FAQs – frequently asked questions
Here you will find answers to frequently asked questions about fermacell® products, their applications, installation and maintenance.
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General
The declaration of conformity is required to demonstrate that the work has been carried out in accordance with ABP P-3981/9177 and must be provided by the installer. The specialist contractor/installer hereby declares that they have installed the fermacell™ floor system in accordance with the certificate of suitability.
fermacell™ joint adhesive and fermacell™ screed adhesive are single-component polyurethane adhesives which, once set, are difficult or impossible to remove.
The following points must be taken into account in advance:
1. Protect your hands with gloves! Hands that have just become soiled must not be cleaned with thinner. They should be washed with plenty of soap and water. Adhesive that has set on the skin can be removed by rubbing in grease or cream thoroughly. Grease or cream can also help prevent the skin from becoming soiled.
2. Clean tools to remove fresh dirt using solvents. Adhesive residues can also be removed from tools afterwards using special cleaners.
3. Remove coarse, hardened dirt mechanically beforehand.
The use of fermacell™® Powerpanel H2The use of O as a curtain wall system and as an external soffit is governed by General Building Approval (abZ) Z 31.4-181.
fermacell® fibre gypsum boards and fermacell® flooring elements can be used on all wall and floor surfaces subject to normal domestic use. These surfaces are exposed to splash water only briefly and to a slight to moderate degree.
In areas of the domestic bathroom exposed to water (the entire floor area, and walls behind or above baths and showers), a waterproofing layer is required on the board surface. fermacell® offers a tested system for this purpose.
Cement-bonded Powerpanel boards
fermacell® Powerpanel H2O is suitable for wall and ceiling constructions, and fermacell® Powerpanel TE for floor systems in domestic wet rooms (bathrooms, showers) as well as in public areas (swimming pools, wellness areas, sanitary facilities) and commercial areas (e.g. commercial kitchens, breweries, dairies). In domestic settings, it is sufficient to additionally seal fixing points and joints. Full-surface waterproofing of the board surface is not required.
For use with fermacell® Powerpanel H2O in public areas, the specific requirements regarding the choice of substrate, the necessary corrosion protection and professional waterproofing must be observed.
Detailed instructions on planning and installation can be found in the installation guide.
All national and European approvals for fermacell™® and Aestuver®® You can find products in the Downloads our website www.fermacell.de
Yes, James Hardie offers a solution here in collaboration with PCI. We recommend using fermacell® Powerpanel TE with a tiled finish.
In consultation with PCI, we recommend the following processing steps:
A substrate with a sufficient gradient; if necessary, install a gradient wedge in conjunction with the composite system or with fermacell™ bonded loose-fill.
Installation of fermacell® Powerpanel TE boards, with the tongue-and-groove joints both glued and screwed or clipped in place.
At the floor-to-wall junction, apply the PCITM Pecitape 120* safety sealing tape using PCITM Seccoral 2K Rapid*, Also seal the area at the front with PCITM Seccoral 2K Rapid and PCITM Pecitape 120* to prevent water from seeping through.
Seal the entire surface using the flexible sealing slurry PCITM Seccoral 2K Rapid* (minimum dry film thickness: 2 mm), ensuring that PCITM Seccoral 2K Rapid* is also applied up the wall to the required height.
Lay the ceramic tiles using PCITM Nanoflott Light* or PCITM Rapidflott* flow-bed mortar.
Grouting the flooring with PCITM Nanofug Premium*.
Installation of flexible joints using PCITM Silcoferm S*.
* When installing PCI products, please refer to the information provided in the latest technical data sheets. Please contact PCI directly for further details.
James Hardie does not offer a direct delivery service for fermacell™ products. Delivery to site is arranged by specialist building materials suppliers.
You can find a building materials supplier near you in the Find a dealer.
Constructions using fermacell® fibre gypsum boards offer the highest levels of stability, fire protection, sound insulation and thermal insulation. Their high quality is officially certified by a wide range of tests carried out by government and independent bodies.
Please see our specification guide for design-related technical specifications in the downloads section.
Due to varying weather conditions or significant fluctuations in temperature and humidity, we recommend using fermacell® Powerpanel H2O .
Garages and carports
Garden sheds and carports are ancillary structures for which building materials do not necessarily require approval. For this reason, simplifications can be made in their construction. This applies, for example, to jointing techniques or surface coatings.
For use with fermacell® Powerpanel H2O For wall and ceiling applications in carports and similar domestic settings, joints can be formed using an adhesive joint. Once the joints have been filled, the board surfaces can be finished either with macell™ roller plaster or a suitable paint system. If the boards are simply butt-jointed, the surface must be covered with a fully reinforced plaster system. Furthermore, our gypsum fibreboards can be used in outdoor areas not directly exposed to the elements, e.g. on carport ceilings or soffits.
Building construction
Powerpanel panels have been approved for use on facades and suspended ceilings in building construction. The structural specifications must be strictly adhered to.
James Hardie offers its own fermacell™ rendering system for surface finishes in this area.
fermacell™ products are available in many countries.
These can be found in the European Technical Assessment ETA-03/0050 for our gypsum fibreboards. The specifications for our fermacell® Powerpanel HD can be found in the European Technical Assessment ETA-13/0609 and in the ABG Z-31.1-178.
You will also find information on the design values for wall panels clad with fermacell® gypsum fibreboards and fermacell® Powerpanel HD for verifying their plate-like load-bearing capacity in accordance with DIN EN 1995-1-1 in conjunction with the National Annex (NA) as a result of wind or seismic loads. Design examples and summary information on the structural possibilities in timber construction using James Hardie products can also be found in the document: "Planning and Installation – fermacell™ and Hardie® Products in Timber Construction". Furthermore, our timber construction planner could provide further added value here.
No, fermacell™ adhesives do not contain any solvents. This applies to fermacell™ joint adhesive, fermacell™ joint adhesive greenline, fermacell™ screed adhesive and fermacell™ Therm™ adhesive. Solvents are not required for this process. fermacell™ Greenline Screed Adhesive and fermacell™ Therm Adhesive are dispersion-based adhesives that cure through the release of water. No solvents are required here either. Certificates from the ECO-Institut Köln are available for all adhesives in the download section.
Unfortunately, we cannot make any general statements.
Customers are kindly requested to contact a local dealer. As the manufacturer, we are unfortunately unable to offer direct sales or collection from our premises.
However, our products are available from specialist building materials retailers. If a product is not in stock at your local store, the retailer can order it from us at any time.
You can find a building materials supplier near you here.
In most cases, the designer authorised to submit plans will find it sufficient to refer to our publicly available documentation, such as the handbook: Structures using fermacell® and Hardie™ products.
If required, the relevant general building inspection certificates or reports will be sent to you by email upon request. Please send us your enquiry via our contact form.
Alongside natural gypsum, so-called FGD gypsum (gypsum from flue gas desulphurisation plants) plays a significant role as a raw material for the gypsum industry. FGD gypsum accounts for around half of Germany’s gypsum requirements. FGD gypsum is produced during the desulphurisation of flue gases from power stations fired with fossil fuels. It is specifically recovered during wet flue gas desulphurisation using the lime (limestone) washing process, following oxidation with air, the separation of the gypsum crystals, and washing and filtering. FGD gypsum consists of very fine-grained, high-purity calcium sulphate and is a raw material that can be used directly.
How to contact the Service Centre (Order Processing)
For any enquiries regarding orders, deliveries or invoices for our products, please contact our customer service team.
The technical specifications and values required for the design of structures can be found in a European Technical Approval (ETA) and/or a national approval. All European and national approvals are available in the downloads section.
No. fermacell® fibre gypsum boards consist of 80% gypsum and 20% paper fibres made from recycled waste paper. After water has been added, these two raw materials are pressed under high pressure into sturdy boards without the use of any additional binders.
The composition and manufacturing process have not changed significantly since the panels were invented in 1970: In the case of gypsum, the natural gypsum previously used has been partially replaced by environmentally friendly flue gas desulphurisation (FGD) and recycled gypsum, whilst cellulose-based substitute fibres have been added to the paper fibres. In fermacell® Firepanel boards, some of the cellulose fibres are replaced by rock wool fibres to achieve a higher level of fire protection.
The fermacell™ joint filler has also always been manufactured without fibres (which may contain asbestos). The reinforcing agent used here is methylcellulose (the base material in wallpaper paste).
All other products were developed and launched on the market after 1980. By that time, asbestos had already been banned.
fermacell® and James Hardie products are available at DIY stores and specialist building suppliers. You can also order items from these outlets if they are not in stock. James Hardie does not offer direct sales.
You can find suitable retailers in the Find a dealer.
You can obtain test certificates and reports via our Customer Centre request:
Telephone 0800 3864 001 or simply use the Contact form on our website.
James Hardie Europe manufactures fermacell® fibre gypsum boards at four production sites. The ETA 03/0050 product approval for fermacell® fibre gypsum boards applies to all production sites. The technical specifications listed there in must be strictly adhered to. Furthermore, fermacell® fibre gypsum boards are tested by the ECO-Institut. These reports also evaluate the boards from all four plants. Due to the raw materials available in different regions, colour variations may occur; these do not represent any loss of quality.
You can find the material approval in the downloads section.
Sustainability
If you can't find what you're looking for here, please feel free to contact your technical sales representative at any time.
We are committed to taking responsibility for nature and the environment. That is why we support you in collecting your single-type fibre gypsum board offcuts on site. Our partnership with local businesses enables us to optimise processes and makes taking part incredibly easy.
Yes. fermacell® fibre gypsum products are recyclable and can be returned to the material cycle after use. This requires that the materials are sorted correctly; the boards must not be contaminated with foreign substances.
Positive. Thanks to their high mass and heat storage capacity, fermacell® fibre gypsum boards help to maintain a stable indoor climate and provide heat protection in summer.
Yes. fermacell® fibre gypsum boards are vapour-permeable, help regulate humidity and contain no volatile organic compounds. This ensures a comfortable and healthy indoor environment.
In the case of structures without a visible surface and with butt joints, it is possible to carry out a dismantling process using materials of the same type.
No, fermacell® fibre gypsum products do not require any additional protective coatings. This results in fewer potential pollutants and makes it easier to recycle them as a single material.
You will usually need environmental product documentation, such as an EPD (Environmental Product Declaration), so that the product can be assessed correctly for building certification. Further requirements depend on the specific building certification scheme.
Yes, fermacell® gypsum fibre products may be eligible for funding under sustainable building schemes. They are made from resource-efficient, recyclable materials and meet key criteria for eco-friendly building materials. However, the specific funding scheme and its requirements are always the deciding factor. If in doubt, please feel free to contact our technical sales representative.
Yes. fermacell® fibre gypsum products support certifications such as BREEAM, DGNB, and LEED, as they meet environmental and health requirements. The relevant requirements and the overall project, including all building materials used, are always decisive for obtaining the relevant certification.
Yes, we have the relevant certificates for many of our products. These can be found directly in our downloads section.
Constructions using fermacell® fibre gypsum products are more sustainable because they meet high standards of fire, sound and structural protection whilst using fewer materials, thereby conserving resources and reducing CO₂ emissions.
Yes. fermacell® fibre gypsum boards are the ideal complement to timber structures, as they combine fire protection, sound insulation and negative CO₂ storage (cradle-to-gate) with environmental benefits, making them perfect for sustainable construction methods. Thanks to the high durability of our products, CO₂ emissions are reduced to a minimum over the entire life cycle.
You’re doing your bit for the environment, because fermacell® fibre gypsum products reduce CO₂ emissions and conserve resources thanks to recycled materials such as paper fibres. Our boards are produced in a resource-efficient manner, are highly durable and perform well, which leads to reduced material consumption. At the same time, you are avoiding energy-intensive natural gypsum mining and opting for an overall highly sustainable material cycle solution.
The gypsum used in fermacell® is mainly derived from flue gas desulphurisation gypsum, a by-product of flue gas cleaning, and is therefore considered to be relatively sustainable. However, the extraction of natural gypsum is also carried out in a sustainable and resource-efficient manner and therefore does not pose a problem.
The main components of our fermacell® boards – gypsum and paper fibres – are sourced primarily from regional suppliers and recycling processes. This reduces transport distances and conserves natural resources.
Yes. fermacell® fibre gypsum products are made almost entirely from natural raw materials. The gypsum is largely sourced from flue gas desulphurisation, where it is obtained as a by-product, or from our own recycling processes. The paper fibres used are made entirely from recycled material. Production is resource-efficient and carried out in accordance with high environmental standards.
No! fermacell® fibre gypsum boards are free from harmful substances, contain no VOC emissions and pose no health risks when used indoors. They are also suitable for sensitive areas such as children’s bedrooms or schools.
The Institut Bauen und Umwelt E.V. (IBU) has had the life cycle assessment of fermacell® fibre gypsum boards and fermacell® flooring elements verified by independent experts. According to the issued EPD (Environmental Product Declaration), fermacell® products save CO2 over their entire life cycle (from raw material and energy extraction through the actual manufacturing phase of the boards to the end-of-life phase including disposal) and are free from substances hazardous to health.
Extremely durable. The panels are moisture-resistant, dimensionally stable and can withstand mechanical stress. A long service life means fewer replacements and therefore a lower environmental impact.
ACOUSTICS
Yes, we recommend fermacell™ SK filler or fermacell™ joint filler, as well as fermacell™ paper reinforcement tape – as described in the installation instructions.
No. For areas without acoustic cladding, we recommend using a standard fermacell® gypsum fibreboard (1200 × 900 × 12.5 mm) with a 4-sided beaded edge instead.
We recommend fixing the boards using 3.9 × 40 mm fermacell™ screws.
Nails or staples are not recommended for this type of fastening.
The spacing depends on how the panels are aligned. The installation instructions state that they can be fitted at intervals of 300 mm or 450 mm, depending on the alignment of the panels.
fermacell® ACOUSTIC Barcode is supplied in the dimensions 900 × 2100 × 25 mm.
No. The panel consists of a 12.5 mm thick fermacell® gypsum fibreboard, to the back of which an acoustic fleece and 12.5 mm thick wooden battens have been glued. The total thickness is therefore 25 mm.
We recommend cladding the formwork around the acoustic panels with strips of standard 12.5 mm fermacell® gypsum fibreboards.
This ensures a level surface for the subsequent cladding.
This depends on the room itself, as well as the furnishings and the installation principles. In living spaces, a significant improvement in acoustics can usually be achieved by covering approximately 30–40% of the ceiling surface with fermacell® ACOUSTIC.
Walls and ceilings
fermacell® Powerpanel HD – Direct boarding on a timber stud frame in timber construction:
James Hardie offers the HD rendering system for fermacell® Powerpanel HD. Further information and installation instructions can be found in the document: "fermacell® and James Hardie in Timber Construction – Planning and Installation".
Our application video is also available to assist you with the installation of fermacell® Powerpanel HD boards. fermacell® Powerpanel HD cannot be used for ventilated facades. Further plastering recommendations are available on request.
fermacell® Powerpanel H₂O – Ventilated curtain wall:
fermacell® Powerpanel H₂O may only be coated using the systems specified in the approval; these can be found in the fermacell® Powerpanel H₂O Außen_Z31-4181. If you wish to use weather protection systems from other manufacturers, please contact us via the technical customer hotline. Other finishes, such as tiles or other plasters, cannot be used! Further installation instructions can be found in our manual: "fermacell® Powerpanel H₂O for external use".
Yes! fermacell® gypsum fibreboards with a thickness of 10 mm or more are classified as arc-resistant to Class LV 1.1.1.1 (the highest classification). Further information on this can be found in the brochure Planning and construction in timber building.
No, although fermacell® Powerpanel H₂O can be used in environments with high humidity and consistently high temperatures, the climatic conditions in saunas and steam rooms are constantly changing. Like any building product, fermacell® Powerpanel H₂O is subject to a certain degree of expansion and contraction, which can then lead to cracks in the joint areas.
Furthermore, additives such as essential oils etc. can cause damage to the board structure. fermacell® Powerpanel H₂O must only be used behind timber cladding in these areas, and even then only with boards butt-jointed at the joints.
Yes, one change of material per wall surface is permitted.
The points to be taken into account are set out in the document fermacell®® Powerpanel H2O Wet room panels – planning and installation listed below.
There is no height restriction under the general type approval for fermacell® Powerpanel H2O. The height restriction is determined by the project-specific structural analysis and calculations regarding wind and snow loads, and by the relevant national building requirements in accordance with the Building Regulations (LBO). This is then carried out in conjunction with the statutory regulations (e.g. Model Administrative Regulation on Technical Building Regulations (MVV TB) or state-specific VV TB), technical rules/building regulations such as the Model Timber Construction Guideline (MHolzRL) and generally accepted rules of technology. (e.g. DIN 4102-4).
Further details can be found in the manual fermacell® Powerpanel H₂O for external use – planning and installation.
In private homes, as well as in hotels and office buildings, there is no need to provide edge protection. The fermacell® gypsum fibreboard is strong enough.
Our guide, "fermacell® kompakt Interior Finishing", is dedicated to the topic of loft conversions. It is available in the downloads section of our website
We offer the fermacell® gypsum fibreboard (one-man panel) specifically for use in loft conversions. With its dimensions of 1500 x 1000 x 10 mm, it is particularly well suited to confined spaces and the spacing of the sub-frame. You can find specific installation instructions in the fermacell® gypsum fibreboard installation guide. Our video: “Attic conversion with fermacell®” can also provide guidance on installation.
The maximum continuous temperature for fermacell® Powerpanel H₂O, fermacell® Powerpanel TE or fermacell® Powerpanel HD boards must not exceed 95 °C.
Cross joints should be avoided when installing fermacell® fibre gypsum boards, fermacell® Powerpanel boards and fermacell® flooring elements.
When laying cross joints, there is no interlocking. The intended "staggered bond" – which is also common in masonry construction – results in greater strength. The risk of through-cracks is reduced.
The wall heating system must be approved by the manufacturer for use with gypsum fibreboards. The manufacturer’s instructions must be followed. The flow temperature of the wall heating system must be limited to a maximum of 55°C. To prevent joint cracks caused by the heating and cooling phases, we recommend that the joints in the macell® gypsum fibreboards be finished as adhesive joints. Depending on the manufacturer’s specifications, other jointing techniques may also be possible.
Please refer to the table below for details of the maximum load capacities. This information can also be found in the manual fermacell®® Powerpanel H2O – the panel for wet rooms.
No.
fermacell® gypsum fibreboards are an ideal material for all aspects of dry interior finishing and can be used universally in construction projects from the basement to the roof. Due to their material composition (gypsum and paper fibres), they are a gypsum-based building material best suited for interior use. The boards can also be used in service class 2 applications, in external areas not directly exposed to the elements.
For outdoor use, cement-bonded fermacell™ Powerpanel products should be used in accordance with the relevant building and structural requirements.
Cement-bonded boards are ideal for this purpose. For years, fermacell®® Gypsum fibreboards for suspended ceilings in outdoor areas, e.g. under roof overhangs, canopies, pergolas or gateways. The fermacell®® However, fermacell® Powerpanel H₂O is the better choice for this application. fermacell® Powerpanel H₂O can be used on external suspended ceilings and roof overhangs in accordance with general type approval Z-31.4-181. A project-specific calculation is required.
The method of fixing fermacell® gypsum fibreboards to the substructure using nails, staples or screws has proven its worth and is supported by relevant technical documentation. On solid masonry, fermacell® gypsum fibreboards can also be bonded using fermacell™ adhesive.
Other alternative methods, such as direct bonding to the substructure or substrate using so-called construction adhesives, are certainly possible; however, given the wide variety of products available on the market, James Hardie Europe is unable to make any recommendations or provide any warranty in this regard.
Yes, that is possible. You can find detailed information on bending radii and processing in the manual fermacell®® Powerpanel H²O – the panel for wet rooms.
The structure of fermacell® gypsum fibreboards and fermacell® Powerpanel boards is the same in both the longitudinal and transverse directions. They can therefore be installed either parallel or perpendicular to the substructure.
To achieve optimum strength, it is nevertheless advisable to lay the longer sides of the panels end-to-end on the substructure and the shorter sides at right angles to them. In the case of single-layer cladding, these should then be glued down where possible.
These specifications apply to both wall and ceiling structures.
The fermacell® Powerpanel H2O can be used on external curtain walls and suspended ceilings in accordance with general type approval Z-31.4-181. The panels require permanent weather protection in accordance with the aforementioned type approval.
Further details on installation can be found in the manual: fermacell™ Powerpanel H2O Outdoor use – planning and installation.
fermacell® Powerpanel HD boards are used for the external cladding of external walls in timber frame construction. Here, they serve as direct cladding for the timber studs and as stiffening panels, whilst simultaneously meeting fire safety requirements and providing weather protection (as a render base board).
In addition, our fermacell® gypsum fibreboards can also be used outdoors in areas classified as usage class 2, i.e. in outdoor areas not directly exposed to the elements.
As fermacell™ Deep Primer and fermacell™ Liquid Membrane are only to be used in combination with fermacell™ Flex Adhesive and the tile covering, the tensile bond strength is assessed for this composite system. The system has been tested and approved by independent institutes. However, before laying the tiling, the primer and liquid film layer can certainly be ‘peeled off’. For this reason, you should, for example, lay down a thin PE film on the dry screed for protection before walking on such a layer and then fold this back section by section.
The fermacell® Vapor gypsum fibreboard is a homogeneous, gypsum-bound drywall board containing paper fibres, which is factory-coated with a vapour barrier and has a hydrophobic face. It combines the structural properties of the fermacell® gypsum fibreboard with the building physics function of a vapour barrier. It can be used both as direct cladding and in combination with an installation layer. It is installed in the same way as the fermacell® gypsum fibreboard, using standard tools and woodworking machinery.
The surface finish of the fermacell® Vapor gypsum fibreboard can be achieved by applying a skim coat, paint or render. Tiling is also permitted.
Instructions on how to handle connection details can be found in the manual: "fermacell® and Hardie® Constructions".
Sheet cut-outs can be made using a hand-held circular saw, a jigsaw (with a carbide-tipped blade) or a handsaw. Holes or round cut-outs can be made using a twist drill (steel drill bit) or a carbide-tipped hole saw (can drill).
fermacell® fibre gypsum products consist of 80% gypsum – a mixture of natural gypsum and flue gas desulphurisation (FGD) gypsum – and 20% paper fibres, which are obtained from waste paper through a recycling process. These two raw materials are processed into a homogeneous mixture and, after the addition of water – without any further binding agents – are pressed under high pressure into stable boards, dried, treated with a water-repellent agent to make them hydrophobic, and cut to the required sizes.
fermacell® fibre gypsum boards do not contain any substances that are harmful to health.
The absence of adhesives means there are no unpleasant odours. The boards and the manufacturing process have been tested by the Rosenheim Institute for Building Biology with regard to healthy living and environmental protection. Due to the excellent results, the fermacell® fibre gypsum boards have been awarded the ‘Tested and recommended by the IBR’ seal of approval. Furthermore, the ECO certificate confirms that they are free from harmful substances.
To help you choose the right wall construction, our Design overview can be used. In addition, there are many other useful documents in our Downloads to be found.
Floor
Insulation materials used for additional thermal and sound insulation, as well as for levelling the surface beneath fermacell® screed elements, must be approved by fermacell® James Hardie®. Our approved insulation materials possess the necessary strength and are tailored to the properties of the screed elements and the required load-bearing capacity. A list of suitable insulation materials can be found here.
Further information on impact sound insulation can be found in the handbook "fermacell™ Floor Systems – Planning and Installation" and in our list of insulation materials. For exposed timber beam ceilings, the fermacell™ honeycomb insulation system is recommended, amongst other solutions, for effective impact sound improvement.
No, that is not permitted.
Garage floors are usually subjected to heavy loads, for example from cars or the use of car jacks.
If the space is to be used solely as a storage room, fermacell® Powerpanel TE can be used. However, in the event of a change of use (new tenant), there is still a risk that the space will be used as a garage (excessive loads).
Insulation from above
Screed panels with polystyrene cladding are the most suitable option. These are available with insulation thicknesses of 20 or 30 mm. It is advisable to supplement these panels with appropriate insulation materials. Our list of insulation materials, which details tested and approved products, will help you with this.
If the subfloor is uneven, you can level it using fermacell™ levelling compound or fermacell™ levelling mortar.
As a general rule, a dry and level subfloor is required for the installation of fermacell® screed elements.
In accordance with building regulations, the floor slab must be waterproofed against rising damp and water pressure. If this is not feasible (e.g. in older buildings), the floor slab must be waterproofed before laying the macell® screed elements. Retrospective waterproofing of the floor slab must be carried out in accordance with DIN 18 533 using a bitumen membrane or a plastic waterproofing membrane.
As unheated conservatories are subject to very large fluctuations in temperature over short periods, leading to an increased risk of condensation in the building materials, the gypsum-based fermacell® gypsum fibre screed elements should not be used here; instead, the moisture-resistant fermacell® Powerpanel TE screed elements should be used. It is recommended that the panels be laid as a floating screed on a compressive-resistant insulation layer, e.g. made of rigid foam.
Further information can be found in the manual: "fermacell®™ Floor Systems – Planning and Installation".
Installing screed elements in an attic only makes sense if the space is inhabited (insulated/heated). In this case, the temperature difference between the top and bottom of the ceiling is so small that a vapour barrier is not required. A vapour barrier is only necessary if the temperature differences are significant (e.g. compared to the outside climate). This applies to both solid and timber-beam ceilings.
No, that's not possible.
The fermacell® screed elements require a full-surface base that is sufficiently load-bearing, level and dry. A sufficiently dimensioned, non-springy subfloor must therefore be in place on the wooden joists, e.g. made of boards or suitable wood-based panels. If there is limited installation height available for the screed, this subfloor can be laid between the wooden joists.
No. The fermacell® Therm25™ element combines a load-distribution layer and underfloor heating in a single system.
The system incorporates a fermacell® gypsum fibreboard, which is glued and screwed or stapled in place as an additional layer above (Option 1) or below (Option 2) the fermacell® Therm25™ elements.
In option 3, fermacell® Therm25™ panels can also be bonded directly to a level, load-bearing substrate without the need for additional fermacell® gypsum fibreboard.
Detailed installation instructions can be found in the document ‘fermacell® Therm25™ Elements – Planning and Installation’.
fermacell® screed elements are made from the same gypsum fibreboards that are used on walls and ceilings. It would therefore, in theory, be possible to use them.
In practical terms, there are a number of reasons against this:
Two-layer planking is not always necessary,
the proportion of joints is greater,
the sound insulation of the wall structure is compromised by the bonding of the panels and the resulting rigidity,
From a fire safety perspective, there is no direct evidence,
and last but not least: the price per square metre is higher.
Yes, the fermacell® Therm25™ panels serve as the ideal backing board for underfloor heating.
Once the heating pipes have been laid, an additional layer of fermacell® gypsum fibreboards or – depending on the application – an additional layer of fermacell® Powerpanel H₂O can be installed.
If the wall space is unobstructed and not blocked by furniture,
Wall-mounted radiators provide a cosy radiant heat. A truly comfortable living environment can be created by combining wall-mounted radiators with underfloor heating.
Detailed installation instructions can be found in the document: "fermacellTM Therm25™ Underfloor Heating Elements – Planning and Installation"
A variety of resilient floor coverings can be laid over fermacell® screed elements, such as carpet, laminate, cork, PVC, linoleum, elastomer and LVT design flooring.
You can find more detailed information on this in the technical documentation: "Installation guidelines for resilient floor coverings on fermacell™ floor systems".
Yes, fermacell® Therm25™ panels are suitable for damp rooms in water exposure classes W0-I, W1-I and even W2-I.
In zone W1-I, the surface must also be fitted with a suitable waterproofing membrane. When using fermacell® Therm25™ elements in zone W2-1 (high moisture exposure), the surface must be covered with a layer of fermacell® Powerpanel H₂O and sealed accordingly. This is only possible with installation method 1.
Detailed installation instructions can be found in the document: "fermacellTM Therm25™ Underfloor Heating Elements – Planning and Installation"
For glued parquet flooring, only those parquet adhesive systems that have been expressly approved by the adhesive manufacturer for the specific screed type should be used. Installation must be carried out in accordance with the adhesive manufacturer’s guidelines.
A list of adhesive manufacturers and their systems is available to download.
Guidance on the correct installation of parquet flooring on fermacell® screed elements can be found in the handbook: "fermacell®™ Flooring System – Planning and Installation" and in the technical documentation: Parquet and other wooden floor coverings on fermacell® flooring systems.
There are often a large number of pipes in the area in front of heating circuit manifolds.In these areas, it is recommended to install fermacell® Therm25™ round elements. If the existing channels are insufficient, additional grooves can be cut directly into the Therm25™ elements. Groove cutters (d = 16 mm) or hand-held circular saws are suitable for this purpose.
If it is no longer possible to use fermacell® Therm25™ panels in these areas, it is recommended that the area be left out during installation and filled in after the pipes have been laid using fermacell® gypsum fibreboards, fermacell™ adhesive mortar or fermacell™ bonded gravel fill.
Detailed installation instructions can be found in the fermacell™ document Therm25™ – Planning and Installation.
fermacell® screed elements are suitable as a substrate for the direct bonding of multi-layer parquet in accordance with DIN EN 13489 (e.g. pre-finished parquet elements) and mosaic parquet in accordance with DIN EN 13488. The latter must be laid in a pattern (e.g. herringbone or cube pattern), as this allows the parquet floor to expand in different directions in the event of swelling.
Mosaic parquet must only be installed in a different direction or using other solid wood species and types of parquet with the adhesive manufacturer’s approval. You can also find information on parquet adhesives in our list of recommendations.
Further information can be found in our handbook: "fermacell® Floor Systems – Planning and Installation".
As wooden floorboards can continue to dry out and shrink, and there is also a risk of knots falling out, a vapour-permeable underlay must be laid before the levelling compound is applied. In the area of the floorboards, a vapour-permeable underlay should be considered before installing the levelling compound, if necessary. To reduce impact noise, the installation of 30 mm fermacell®® We recommend screed elements containing wood fibre (2 E 31).
Further information can be found in the manual fermacell™® Flooring systems: design and installation to be found.
Depending on the installation method, different screws must be used to fix the fermacell® Therm25™ panels in place:
Option 1 with top cover plate:
For a 10 mm cover plate: fermacell™ drywall screws 3.9 × 22 (or special expansion staples of the same length)
For cover plates > 10 mm: fermacell™ drywall screws 3.9 × 30 (or special expansion clips of the same length)
For 12.5 mm fermacell® Powerpanel H₂O as a covering board: fermacell™ Powerpanel TE screws 3.5 x 23 mm (or special expansion clips of the same length)
Option 2 with a cover plate on the underside:
fermacell® Powerpanel H₂O screws 3.9 × 35 or special expansion staples (staple length
approx. 32–35 mm)
Option 3 does not require any screws.
Detailed installation instructions can be found in the document: fermacell® Therm25™ Underfloor Heating Elements – Planning and Installation
fermacell® screed elements are pre-treated with a primer at the factory. An additional primer is required if the adhesive manufacturer specifies a system-specific primer.
Decoupling mats are often used or recommended to bridge cracks in solid screeds. However, due to the material properties of fermacell® screed elements, a decoupling mat is not required in this case.
You can find suitable screed systems in the handbook: "fermacell™ Floor Systems – Planning and Installation".
As wooden floorboards can continue to dry out and shrink, and there is also a risk of knots falling out, a vapour-permeable protective layer must be laid before the levelling compound is applied. In the area of the floorboards, a vapour-permeable underlay may need to be considered before installing the macell™ levelling compound. To reduce impact noise, we recommend installing the 30 mm macell® screed element with wood fibre (2 E 31).
Further information can be found in the manual: fermacell™ Floor Systems – Planning and Installation.
There are two different fermacell™ Therm25™ templates:
fermacell™ Therm25™-167 template for use with fermacell® Therm25™ elements with a 167 mm installation spacing
fermacell™ Therm25™-125 template for use with fermacell® Therm25™ elements, 125 mm installation spacing
The fermacell™ Therm25 template is the same size as the fermacell® gypsum fibreboard (1500×1000 mm) and is positioned precisely on the fermacell® Therm25™ elements, in the exact spot where the cover board is to be laid, prior to bonding.
When using fermacell™ Therm adhesive, at least 9 fixing points are required per cover panel (1500 x 1000 mm). To ensure these are evenly distributed, exactly one fixing point should be applied to each grey-shaded area.
(Note: When using fermacell™ screed adhesive, all fixing points on the template must still be used).
If heating pipes are visible in the holes during the inspection of the fields, these must be marked or covered with tape to ensure that no fasteners are attached at these points.
The fermacell™ Therm adhesive or fermacell™ screed adhesive can then be applied, with the fermacell® gypsum fibreboard used as a cover board. The template is placed on the covering board in the same orientation and the covering board is secured with at least 9 (or 59 or 70 in the case of fermacell™ Screed Adhesive) screws/clips.
Each pallet of fermacell® Therm25™ elements comes with a fermacell™ Therm25™ template. This can also be reordered separately if required:
fermacell™ Therm25™-167 Template: 79190
fermacell™ Therm25™-125 template: 79189
Detailed installation instructions can be found in the document: "fermacellTM Therm25™ Underfloor Heating Elements – Planning and Installation". A helpful installation video is also available.
Standard formats
Tiles and natural stone slabs with a maximum edge length of 330 mm may generally be used on all fermacell® screed elements.
If impact sound insulation boards made of mineral wool or fermacell® screed elements laminated with mineral wool are used, natural stone or terracotta tiles are not permitted.
Tiles are laid using the thin-bed method on fermacell® gypsum fibre screed panels. When using fermacell™ Flex adhesive, a primer is not required. Tiles can be laid on fermacell® Powerpanel TE using either the thin-bed or medium-bed method. When using fermacell™ Flex Adhesive, a primer (e.g. fermacell™ Deep Primer) is required.
Large-format tiles
fermacell® screed elements are suitable for laying stoneware tiles of any size. Certain specifications must be strictly adhered to during installation. Further information on this can be found in the tile list.
Further necessary information can be found in our handbook: "fermacell®™ Floor Systems – Planning and Installation", as well as in the document: "Installation Guidelines for Tiled Flooring on fermacell Floor Systems". Only approved systems may be used for bonding. Please refer to the same document for further guidance.
No.
The fermacell™ screed adhesive has been tested and approved exclusively for bonding the interlocking joints of the screed elements. For laying tiles, a suitable tile adhesive, such as fermacell™ Flex Adhesive, must be used.
No vapour barrier or vapour retarder must be installed beneath the fermacell™ Bound Loose-fill T.
The substrate for fermacell™ Bound Loose-fill T must be load-bearing, clean, permanently dry and free from release agents. To ensure the necessary adhesion, the substrate must be primed. Do not use a separating layer, anti-sagging agent or PE film.
The installation of a vapour barrier over the fermacell™ Bonded Loose-fill T may be necessary for structural reasons and should be discussed with a building expert if necessary. In the manual fermacell®™ Flooring systems – design and installation... describes how to install it correctly.
Yes. With option 3, fermacell® Therm25™ panels can be bonded directly to a level, load-bearing substrate without the need for additional fermacell® gypsum fibreboard.
A wide variety of insulation layers can be installed beneath fermacell® flooring elements. For more detailed information, please refer to our flooring installation guide.
fermacell®® Attic insulation panels feature a tongue-and-groove design for joining. They simply slot together across their surface and require neither adhesive nor any other fasteners. Only joints at the edges or where they connect to other components need to be sealed. Standard construction foam, available as a single-component (1-component) or two-component (2-component) product, has proven effective for this purpose.
The fermacell™ Bonded Loose Fill T consists of recycled foam plastic (particle sizes 1–4 mm) and a cementitious binder. Once mixed, it can be worked with for approximately 30 minutes and is ready for foot traffic after approximately 6 hours. After approx. 24 hours, the fermacell® screed elements can be laid on top. fermacell™ Bonded Loose Fill T can be used under all fermacell® screed elements as well as under the fermacell® Powerpanel TE. fermacell™ Bonded Screed T can also be used under other types of screed, such as mastic asphalt, cement and anhydrite screed. The compressive strength must be taken into account! Further information can be found in our product data sheet.
The areas of application, requirements and correct installation procedures are described in the handbook: fermacell® Floor Systems – Planning and Installation.
Two different fermacell™ adhesives are available for installing fermacell® Therm25™ panels. The choice of the appropriate product depends on the specific
Scope of the project:
For projects in application areas 1 and 2: fermacell™ Therm Adhesive (or fermacell™ Screed Adhesive)
For projects in application areas 3 and 4: fermacell™ screed adhesive
With the introduction of fermacell™ Therm adhesive, the fermacell™ Therm templates have been adapted so that they can be used for installation with either adhesive.
When installing using fermacell™ Therm adhesive, for Option 1 with an upper cover plate, there must be exactly one free fixing point per grey-shaded and numbered
To make use of the space on the fermacell® floor element:
For fermacell®Therm25™-125 and -167, this means 9 fixing points
When installing using fermacell™ screed adhesive, in Option 1 with an upper cover plate, all remaining fixing points on the templates for fermacell® Therm25™ elements
(where there is no heating pipe):
With fermacell® Therm25™-125, up to 59 fixing points
With fermacell® Therm25™-167, up to 70 fixing points
Information on the areas of application and detailed installation instructions can be found in the document: "fermacellTM Therm25™ Underfloor Heating Elements – Planning and Installation".
The creaking noises when walking are not usually caused by the fermacell®® not due to the screed itself, but rather to the use of fill material or some other factor in the sub-base.
fermacell™ anti-shedding fleece is capable of bridging gaps of up to 5 mm and knotholes of up to 25 mm. For wider gaps and larger knotholes, we recommend filling the gaps and holes with foam (construction foam can be used), sealing them with adhesive, or covering them with fixed plywood panels. This prevents the tear-resistant fermacell™ anti-sagging fleece from sagging.
No.
The fermacell™ thermal insulation loose-fill is designed for installation beneath fermacell®® The screed elements are too soft and are therefore unsuitable for this purpose.
For further information, please contact Product data sheet is available.
Under fermacell®® Of all screed components, only fermacell™ levelling screed and fermacell™ bonded screed have been tested and approved.
In standard residential areas, the use of 25 mm screed elements (2 E 22) is sufficient. If higher load-bearing capacities are required, e.g. in office buildings, an additional 10 mm gypsum fibreboard layer is necessary to distribute the load. Changes in thermal resistance must also be taken into account. Further information on this can be found in the handbook: fermacell® floor systems – planning and installation.
Using an additional layer also makes it possible to use large-format tiles. You can find more information on this topic in our FAQ Centre: Important Information under the search term 'tiles'
The key benefits compared to conventional wet screeds, such as cement screed, self-levelling screed, anhydrite screed, etc., these screed elements offer: short installation times, rapid readiness for use, no construction moisture, low build-up heights and low weight.
The fermacell® Powerpanel TE 2 E 22 screed panel has been tested and approved for installation on underfloor heating systems in Application Category 1 (residential buildings), including in private bathrooms. If a floor-level shower is to be installed, the fermacell® Powerpanel TE screed element must be used.
As cement-based products, fermacell® Powerpanel TE screed panels are also suitable for wet areas in public spaces and can be used in bathroom installations. The available height for the floor structure and a level, dry substrate are essential prerequisites for the installation of fermacell® Powerpanel TE on approved underfloor heating systems. Any necessary levelling must be carried out in accordance with the installation guidelines as set out in the document: "fermacell® Floor Systems – Planning and Installation".
Further information on underfloor heating systems can be found in the document: "fermacellTM Therm25TM Underfloor Heating Systems – Planning and Installation".
Yes, that is possible.
If there are no plans to convert the loft at a later date, the tongue-and-groove boards or OSB boards must be laid before installing the fermacell™® Attic insulation panels must be secured with screws. If the space is to be converted for residential use at a later date, a stable and load-bearing substrate must be created. To this end, stabilisation measures must be carried out, for example by installing an additional wood-based panel.
fermacell™ thermal insulation loose-fill consists of natural, expanded perlite. It is ideal for providing seamless thermal insulation in cavities, e.g. in timber-beamed ceilings, roofs and sloping ceilings, or stud walls.
Due to its compressive strength, fermacell™ thermal insulation fill is not suitable for use as a levelling fill beneath fermacell® screed elements!
Further details can be found in the product data sheet fermacell™ thermal insulation fill. Unused fermacell™ thermal insulation loose-fill can be used to improve the soil!
fermacell™® Screed elements weigh a maximum of 32 kg/m². This means that the load on the ceiling is minimal. With the honeycomb insulation system, the weight increases by approx. 45 kg/m², which does not require separate structural analysis for timber-beamed ceilings in newer buildings without visible defects or structural damage, as the original structural calculation should have taken into account a live load of 200 kg/m². When modernising older buildings, it is essential to consult a structural engineer.
Please note that the screed honeycomb must always be laid directly onto the subfloor and then filled with fermacell™ honeycomb fill. If a levelling of more than 3 mm is required, this is achieved using fermacell™ levelling fill on top of the honeycomb.
Further guidance on correct installation can be found in the manual fermacell®® Flooring systems – design and installation to be found.
The structural performance data for fermacell® screed elements and fermacell™ loose-fill materials can be found in the handbook: "fermacell® Floor Systems – Planning and Installation". Please contact the relevant insulation manufacturer for details regarding additional insulation materials.
Yes, it can be used in damp areas (up to W2-I in accordance with DIN 18534) as the top layer of macell® Therm25™ screed elements.
In damp rooms where fermacell® Therm25™ screed panels are not used, the fermacell® Powerpanel TE screed panel should be used.
The fermacell™ honeycomb insulation system can also be used beneath the screeds mentioned. It is advisable to use it on wooden floors in combination with an impact sound insulation board laid on top of the fermacell™ honeycomb insulation system.
fermacell™ levelling compound is a specially dried, mineral-based aerated concrete granulate. The angularly crushed granules, which vary in grain size and have a rough surface, interlock when poured and levelled. Due to the grain size, the required stability is only achieved at a minimum layer thickness of 10 mm.
Yes, we can assist you with a professional installation plan – tailored specifically to your building project.
You can obtain a free, no-obligation customised installation plan – including a materials list with quantities, a heat output calculation for each room and a floor plan to help with the installation – by contacting: XXXXXXX.
The top surface of the fermacell® flooring elements features printed markings (centred: ‘fermacell® flooring elements’; on the stepped joint: product name, CE marking, barcode, etc.). The elements are laid in the room from left to right.
The material properties of the screed elements are the same on both sides. In principle, therefore, it would not matter which side is on top.
When laying the tiles, simply ensure that the interlocking edges are positioned correctly. The tiles should always be laid on top of one another, never slid underneath!
The 10 mm gypsum fibreboard can be used to level out differences in height between different floor coverings (e.g. between carpet and parquet). To do this, the fermacell® gypsum fibreboard can be bonded to the screed elements as a third layer and fixed with screws or staples. The correct installation of the third layer is described in the "fermacell® Screed Elements Installation Instructions". The various floor coverings must be laid in accordance with the manufacturers’ installation instructions.
The use of 10 mm gypsum fibreboards for levelling on solid floors or wood-based panels is not permitted.
The fermacell™ honeycomb insulation system consists of the fermacell™ screed honeycomb, the fermacell™ honeycomb fill and the fermacell® screed element. The fermacell™ screed honeycomb is a cardboard honeycomb with a closed back, available in thicknesses of 3 or 6 cm, which is filled with the special fermacell™ honeycomb fill.
This honeycomb insulation system, laid directly onto the (unfinished) timber beam ceiling, provides additional weight and, in combination with the floating fermacell® screed element, helps to reduce sound transmission. The sound-insulating effect of this system is significantly enhanced by decoupling the sub-ceiling (e.g. using a spring-mounted suspension system).
For further information on which fermacell® screed elements are suitable, please refer to the handbook: "fermacell™ Floor Systems – Planning and Installation"
The maximum screed thickness for fermacell™ levelling screed is 100 mm in application area 1 (private residential use). In all other application areas, it is 60 mm.
Compaction is generally not required. However, the fill height may be dictated by fire safety or sound insulation requirements. Furthermore, the fill height may be limited by the use of large-format tiles. The use of underfloor heating or suitable mineral wool insulation boards on the levelling screed requires a cover board, e.g. a 10 mm fermacell®® Plasterboard.
You will find a clear overview in the manual fermacell®™ Flooring systems – design and installation.
The fermacell® Therm25™ panel combines a load-distribution layer and underfloor heating in a single system.
There are three installation options:
In variants 1 and 2, an additional fermacell® gypsum fibreboard is used to complement the system; this is glued and screwed or stapled in place as an extra layer above or below the fermacell® Therm25™ elements.
Depending on the required dead load / live load (i.e. the project-specific application), the required thickness of the additional fermacell® gypsum fibreboard may vary.
In option 3, fermacell® Therm25™ panels can also be bonded directly to a level, load-bearing substrate without the need for additional fermacell® gypsum fibreboard.
Option 1:
Covering on the top with an additional fermacell® gypsum fibreboard, fully bonded and secured to the fermacell® Therm25™ panel
Option 2:
An additional fermacell® gypsum fibreboard is installed on the underside; the fermacell® Therm25™ panel is then bonded and secured over the entire surface
Full-surface filling on the top surface
Option 3*:
The fermacell® Therm25™ panel is bonded over its entire surface to a level, load-bearing substrate. The top surface is then skim-coated over its entire area.
* Note: The fermacell® Therm25™ panels do not improve the acoustic or fire insulation properties of the exposed ceiling
Detailed installation instructions can be found in the document: "fermacellTM Therm25™ Underfloor Heating Elements – Planning and Installation".
When discussing structures using fermacell® flooring elements, the term 'systems' is very often used.
Unlike wall structures, floor structures are, quite literally, built upon one another. This means that the weakest link in this structure determines the performance of the entire structure. The fermacell® flooring element takes on the load-bearing and load-distribution functions. To ensure this, the substrate (e.g. fill, insulation material) must have a minimum strength. The structures and products shown in our fermacell® installation guides have been tested and guarantee this strength. Of course, due to structural requirements, it may happen that the required structure is not mentioned in the documentation. In such cases, please contact our technical customer hotline:
Thanks to the stepped joint, fermacell® screed elements can be used to create a secure (mechanical) bond even in the area of doorways.
Building physics
No, the jointing techniques are consistent with the fire safety certificates. We can send these to you on request.
In general, fermacell® fibre gypsum boards – regardless of its thickness – is a non-combustible material with a building material classification of A2 in accordance with DIN EN 13501-1.
Classification into so-called fire resistance classes (designated, for example, as F30) always refers to the entire structure and does not depend solely on the cladding material used and the number of layers.
Other factors also come into play here, such as the type of construction (e.g. wall/ceiling), the insulation materials used, fixings, the substructure, etc. You will find a clear overview of the relevant parameters and components in our specification guide.
The blanket statement that "one layer of fermacell® gypsum fibreboard is equivalent to F30" is therefore incorrect.
Passage through components
fermacell® boards are non-combustible and can be installed right up to the flue pipe in areas where the pipe passes through building elements, e.g. in timber construction. fermacell® Powerpanel H₂O boards show no change during use. In exceptional cases, fermacell® gypsum fibreboards may experience dehydration in the immediate vicinity (1 to 2 cm) of the flue pipe, but this is usually covered by the flue pipe collar and is merely a visual impairment. Non-combustibility remains guaranteed. Flue pipes must maintain a distance of at least 20 cm from wooden substructures or other combustible building materials. Cavities between the flue pipe and the wooden substructure must be completely filled with non-combustible insulation materials (e.g. rock wool). Local building regulations must be observed.
Casing for flue pipes
Chimney linings must not be constructed using fermacell® boards. In accordance with the Model Fire Safety Regulations (M-FeuVO), flue systems must be constructed as shaft linings with a certificate of suitability (General Building Inspection Test Certificate). This certificate of suitability is not available for the aforementioned fermacell® products. The installation of fermacell® products directly behind the flue pipe depends on the distance between the flue pipe and the fermacell® board and is subject to the decision of the master chimney sweep.
Further information can be found in the handbook: "fermacell® Gypsum Fibreboards in Drywall Construction – Planning and Installation".
No
There are no fire safety tests for applications involving suspended ceilings and ventilated curtain walls. Due to its purely mineral composition, fermacell®® Powerpanel H2O panels are non-combustible and meet the requirements of building material class A1 in accordance with DIN EN 13501-1. The fire safety requirements for building components are laid down in building regulations.
The impact sound insulation provided by loose-fill materials always depends on the overall construction of the floor in question. Generally speaking, as a loose granular material, fermacell™ levelling fill offers better impact sound insulation than bound fill.
For example, on solid slabs (400 kg/m²), a reduction in impact sound of 31 dB is achieved using 45 mm fermacell® screed elements with mineral fibre (2 E 35) and at least 20 mm of fermacell™ levelling compound.
Depending on the overall construction, the fermacell™ Bound Loose-fill T still achieves an improvement in impact sound insulation of 27–30 dB.
Further examples of the use of levelling screed are provided in the handbook: "fermacell® Floor Systems – Planning and Installation".
fermacell® gypsum fibreboards and fermacell® screed elements are primarily made of gypsum. When exposed to high temperatures for prolonged periods (above 50 °C), gypsum releases its crystalline water and loses strength. For this reason, the flow temperature must be limited to a maximum of 55°C, for example in hot-water underfloor heating systems.
fermacell® Powerpanel boards and fermacell® Powerpanel TE screed elements are cement-bound and can withstand temperatures of up to 95°C on a permanent basis.
Further information on this can be found in the "Gypsum Data Book" published by the German Gypsum Association: www.gips.de
No, the specifications apply only to indoor use and to static loads.
Further information on cantilever loads can be found in the document: "fermacell® Gypsum Fibreboards in Drywall Construction – Planning and Installation".
Impact sound insulation boards made from wood fibre are significantly stronger than those made from mineral fibre. They retain their strength even when subjected to pressure or walked on during transport, storage and installation.
With mineral fibre impact sound insulation boards, there is a risk that the stabilising adhesive structure of this material will be irreversibly damaged when subjected to stress – for example, from foot traffic during installation – thereby compromising its strength. However, when installed with due care (e.g. using load-distribution boards made of gypsum fibre during installation), mineral fibre boards offer slightly better sound insulation. Mineral wool insulation materials are non-combustible and contribute positively to fire resistance.
In the case of fermacell® panels laminated with mineral fibre at the factory® The use of screed elements reduces the risk of damage, as there is no direct foot traffic during installation.
To meet the F30-B fire safety requirement, the fermacell® 2H13 ceiling system must be installed with a two-layer cladding of fermacell® gypsum fibreboards measuring 1500 x 1000 x 10 mm.
In the first layer, the fermacell® gypsum fibreboards are installed tightly butted (edge to edge) without joint filling. The second layer is fixed to the first layer of boards with the joints offset and without relying on the underlying structure. This construction can be carried out with or without insulation.
Further information can be found in the handbook: "fermacell® Gypsum Fibreboards in Drywall Construction – Planning and Installation".
At Fermacell® fermacell® Manual® Flooring systems – design and installation: you will find information on point loads and live loads.
Depending on the available installation height for the floor, the installation of the 45 mm fermacell™® Screed elements with mineral fibre (2 E 35) or 30 mm fermacell®® We recommend using a screed element with mineral fibre (2 E 32) on top of a 20 mm layer of fermacell™ levelling compound.
Further dry screed systems are described in the handbook fermacell™® Flooring systems – design and installation shown.
The F 30-B fire resistance rating required for the loft conversion is achieved in the sloping roof (hard roofing) using fermacell®® Roof structure 2 HD 11 (1 x 10 mm fermacell™)® (gypsum fibre boards).
Further information can be found in the manual: Construction overview - fermacell®® and Hardie™® to be found.
The structural performance data for fermacell® screed elements and fermacell™ levelling compounds can be found in the handbook: "fermacell® Floor Systems – Planning and Installation". Please contact the relevant insulation manufacturer for details regarding additional insulation materials.
Light and medium-weight items (pictures, paintings, wall sconces) can be secured using wall plugs and screws (with a full-length thread, at least 5 mm in diameter).
In the brochure fermacell™® Plasterboard in drywall construction – planning and installation The topic of load securing is covered in more detail.
To achieve good airborne and impact sound insulation performance in relatively lightweight, multi-layered timber-beam ceilings, the following options are available:
Increase in the mass per unit area of the rough floor (e.g. using the fermacell™ honeycomb insulation system)
Reducing the stiffness of the impact sound insulation board, e.g. screed elements containing wood fibre or mineral fibre (whilst ensuring that the dry screed retains sufficient compressive strength)
Decoupling the suspended ceiling from the wooden beams (e.g. using a spring-loaded suspension system)
Cavity insulation using fibrous insulation materials (e.g. mineral fibre) in the area of the suspension and between the wooden beams
Further dry screed systems are described in the handbook: fermacell™® Flooring systems – design and installation shown.
Fermacell® gypsum fibreboards and fermacell® Powerpanel H₂O may be used as non-combustible boards behind freestanding stoves, provided that the clearance specified in the stove’s approval documentation for combustible surfaces is maintained.
Areas that are not visible or are enclosed, such as those behind stoves, inside fireplaces and tiled stoves, or the covers of stoves, fireplaces and tiled stoves, must not be constructed using gypsum-based boards. fermacell® Powerpanel H₂O boards may also be used in these areas, but do not fulfil the functions of fire protection boards.
If you have any further questions, including regarding the construction of the chimney or the chimney cladding, please refer to the information service provided by the German Gypsum Association: "Gypsum materials for chimneys, fireplaces and flues". For any questions regarding the use of non-combustible building materials, please always contact your local chimney sweep.
You will also find information on this in our handbook: "fermacell® and Hardie® Constructions".
Processing
There are no specific requirements regarding the spacing of the substructure for external suspended ceilings or curtain-wall, rear-ventilated façades. The restrictions arise from the project-specific design and structural analysis with regard to wind and snow loads, and from the relevant national building requirements in accordance with the Building Regulations (LBO). This is then carried out in conjunction with the statutory regulations (e.g. Model Administrative Regulation on Technical Building Regulations (MVV TB) or state-specific VV TB), technical rules/building regulations such as the Model Timber Construction Guideline (MHolzRL) and generally accepted rules of technology. (e.g. DIN 4102-4).
The spacing of the substructure is determined, among other things, by wind loads and must be calculated for each building by a structural engineer. According to the approval, the centre-to-centre distance of the substructure must not exceed 625 mm in a rear-ventilated curtain wall façade and 420 mm in a suspended ceiling.
Detailed information on this can be found in the manual fermacell® Powerpanel H₂O – for outdoor use can be taken from.
The screws are fitted exclusively to the vertical CW profiles in order to prevent stress between the partition wall and the surrounding components.
The CW profiles can, for example, slide within the upper and lower U-profiles as the wall cladding expands or contracts, thereby preventing any cracks from forming in the wall surface. Rattling noises are prevented by the U-profile being clamped between the fermacell® board and the CW profile. Installation instructions for the cladding can be found in the handbook: "fermacell® Gypsum Fibreboards in Drywall Construction – Planning and Installation".
Please note the following information regarding the weights and sizes of the tiles. Wall tiles (ceramic or natural stone) may be installed on fermacell® gypsum fibreboards and on fermacell® Powerpanel H2O can be laid using the thin-bed method.
The weight of the top layer, including tile adhesive, must not exceed 50 kg/m².
Tiles may also be laid on single-layer panelled walls without any restrictions on the tile size. It is not necessary to reduce the spacing of the substructure. Primers must be used if the manufacturer of the tile adhesive specifies this. Further information on installation can be found in the manual: "fermacell® Gypsum Fibreboards – Installation Instructions".
No, this method of fixing is not permitted.
Due to the properties of the material, the panel can only be installed on a metal or timber substructure, depending on the specific application. Further information can be found in the manual fermacell® PowerpanelH2O – the wet room panel – design and installation.
Additional reinforcement of the joints in the fermacell® gypsum fibreboards is only necessary if a suitable thin-set plaster/surface filler with a layer thickness of at least 1 mm to a maximum of 4 mm is to be applied as a surface finish and the fermacell™ joint filler is used as the jointing method. In this case, the fermacell™ fabric tape is bonded over the finished and dry joint. PVAC glue (white glue) must be used for this purpose.
Further information can be found in the manual fermacell® Gypsum Fibre Boards – Installation Instructions can be found in.
Yes, fermacell® gypsum fibreboards may be fixed directly to wood-based panels with low expansion and shrinkage rates, e.g. cross-laminated timber, structural plywood and OSB/4 boards.
During installation, a joint offset of ≥ 200 mm must be maintained between the joints in the fermacell® gypsum fibreboards and those in the wood-based panels. The adhesive joint method and the clip-fixing method must be used.
Further information can be found in the handbook: "fermacell® in Timber Construction – Planning and Installation".
In addition to applying fermacell™ roller plaster to the surface of fermacell® gypsum fibreboards, it is also possible to use thin-coat plaster systems (1 to 4 mm layer thickness, mineral or synthetic resin plasters) in accordance with the manufacturer’s guidelines. Barrier primers suitable for gypsum substrates and included in the plaster system are recommended. When using a filler joint, this must also be reinforced with fermacell™ mesh tape. In the case of adhesive joints and drywall edges with paper reinforcement strips, additional reinforcement of the joints is not required. The thin-coat plaster must be cut with a trowel at corner and wall junctions.
Further information can be found in the manual: "fermacell® Gypsum Fibreboards – Installation Instructions".
As different components are subjected to different stresses and may therefore move in different ways, particular care must be taken when joining these components at corners.
In domestic building work, it is standard practice to use a flexible sealant (acrylic – not silicone!). To ensure flexibility, a minimum joint width of 5 mm must be maintained.
The acrylic should have an elongation of at least 20% (check the information on the cartridge). It’s best to leave cheap products on the shelf. Construction foam is not suitable; it does not set properly.
Further details and options can be found in the handbook: "fermacell® and Hardie® Products in Timber Construction – Planning and Installation"
Yes, you can fix fermacell® gypsum fibreboards directly to masonry using fermacell™ adhesive.
The substrate (masonry, plaster) must be dry, sufficiently strong and as level and non-shrinking as possible (no fresh masonry). No moisture must be allowed to penetrate the substrate from the outside. Installation instructions can be found in the manual: "fermacell® fermacell® gypsum fibreboards – Installation instructions".
There is no tested and approved solution for non-load-bearing substrates, e.g. directly on tiles. Structural solutions are possible using fermacell® wall cladding or facing shells. The various solutions are outlined in the document: "fermacell® Gypsum Fibreboards in Drywall Construction – Planning and Installation".
Walls and ceilings clad with fermacell® boards must be of at least quality grade 2 and must be clean, dry and sound. No additional priming is required for fermacell® boards that have already been treated with a water-repellent coating at the factory. Application must not take place at temperatures below +5°C. fermacell™ roller plaster is applied undiluted in a criss-cross pattern using a suitable roller and then textured.
The fermacell™ joint filler is a gypsum-based material and requires water to set. The joint edges of the gypsum fibreboard are absorbent and draw water from the filler. If the joint is too narrow, the filler dries out too quickly and fails to set properly (it ‘dries out’) and cracks form.
This problem does not arise with joints that are too wide (up to a maximum of 20 mm). In this case, the filler should not be mixed too thinly (otherwise it would shrink too much as it dries and form cracks).
The best results are achieved using standard twist drills for metal. These drills work equally well in both fermacell® gypsum fibreboards and fermacell® Powerpanel boards. As both types of board are made from mineral raw materials, the drill bits may need to be resharpened after repeated use.
Larger cut-outs, e.g. for sockets, can be easily made using bimetal (standard) or carbide-tipped drill bits.
There are no manufacturer’s instructions for removing the coatings mentioned above. In the case of wallpaper, it is helpful to perforate it first and soak it using a wallpaper remover or diluted water (add a splash of washing-up liquid). Do not allow the panels to become thoroughly soaked!
In the case of paint coatings, it should be checked whether they are suitable as a substrate for the new coatings; if so, there is no need to remove them. Alternatively, the coating can be sanded down. Afterwards, a new coat of primer is required. Thanks to the homogeneous structure of the fermacell® gypsum fibreboards, the strength of the surface is maintained.
The removal of textured plaster depends on the type of finish and the thickness of the coating, and cannot be carried out without a fair amount of sanding and filling work.
If you are planning to apply a new coat of textured plaster, it may be helpful to apply a layer of scrap paper beforehand, which will later serve as a separating layer during renovation work.
Panels with right-angled edges are installed using the adhesive joint method.
Further information can be found in the manual fermacell® Powerpanel H2The wet room panel – planning and installation.
fermacell™ drywall screws (countersunk screws) are specially designed for fixing fermacell® fibre gypsum boards to timber and metal substructures.
The thread on these screws does not extend all the way to the head (as is the case with many no-name plasterboard screws), but ends approximately 8 mm before the surface of the screw head. This allows the thread to cut its own path through the fibre gypsum board and press the board tightly against the substructure. With no-name screws, there are often surface irregularities and misalignments in the board joints. Quick-fit screws for plasterboard (trumpet-head screws) are also unsuitable, as the large head does not countersink into the solid fibre gypsum board. This results in unevenness or the board edges breaking off.
fermacell® gypsum fibreboards have a stamp on the back showing approval and manufacturing details.
They are manufactured to be homogeneous and have the same properties on both sides. However, due to manufacturing tolerances, the reverse side of the panels may have unevenness and imperfections in the finish. The embossing on the reverse side may also show through the coating. It is therefore advisable to install the panels with the unstamped side facing outwards. If the reverse side is nevertheless installed facing outwards, this does not pose a structural problem. In this case, the reverse side should be treated with a fine filler before further coating.
Cement-bonded fermacell® Powerpanel boards
fermacell® Powerpanel boards feature embossing on the front. This also marks the centre of the board and makes it easier to fix in place. fermacell® Powerpanel boards have a very smooth front and a back that is usually sanded and rougher. Although the board has a homogeneous cross-section, it is therefore recommended that it be installed with the correct side facing outwards. The same applies here: if the reverse side is nevertheless installed facing forwards (rough surface facing forwards), this does not pose a structural problem. If a smooth surface is desired, the rough surface should be smoothed using fermacell™ Powerpanel fine filler.
In addition to the adhesive grouting method, there are two trowel-applied grouting methods.
Adhesive joint: Only fermacell™ joint adhesive must be used to create the adhesive joint. The board edges cut to size at the factory or those sawn to a sharp edge on site must be free of dust and dry. The joint adhesive is applied to the edge of the fixed board. The next board is then pressed tightly against it. The width of the joint should then be no more than 1 mm. Depending on the room temperature and humidity, the adhesive will have cured after approximately 18 to 36 hours.
Trowel joint: To achieve a flawless, mechanically bonded joint in the trowel joint of the right-angled or mitred tile edge, the following joint widths should be used:
- 5–8 mm for 10 mm board thickness
- 6–9 mm at 12.5 mm
- 7–10 mm for 15 mm or 18 mm
The joints must be filled to the depth of the board using fermacell™ joint filler in 2 to 3 coats, depending on the quality requirements.
Joint with drywall edge: Gypsum fibreboards with drywall edges are butt-jointed, reinforced in the area of the chamfered edge using fermacell™ TB reinforcement tape or fermacell™ paper reinforcement strips, and filled with fermacell™ joint filler.
Further information can be found in the handbook: "fermacell® in drywall construction – planning and installation".
The spacing of the fasteners is determined, among other things, by wind loads and must be calculated for each building by a structural engineer. Guidance on this can be found in the *fermacell® Powerpanel H₂O for External Applications – Design and Installation* manual.
fermacell® gypsum fibreboards are hydrophobic-treated at the factory. It is not necessary to apply, for example, a wallpaper primer (unless required by the manufacturer of the wallpaper paste), as the fermacell® surface cannot be damaged when the wallpaper is stripped due to the homogeneous board structure.
With certain topcoats, such as silicate paints, textured plasters or tiles, a primer may be required to control the absorbency of the substrate. In such cases, the manufacturer’s instructions must be followed.
Further information can be found in the fermacell® Gypsum Fibreboard Installation Guide.
No, that isn’t necessary. You simply need to ensure that the panels are fitted tightly together. This is also sufficient from the point of view of sound and fire protection.
One of the three fermacell™ jointing techniques (adhesive/filler joint) must be used only for the outer layer of the fermacell® gypsum fibreboards.
Further information can be found in the handbook: "fermacell® and Hardie® products in timber construction – planning and installation".
fermacell® gypsum fibreboards and fermacell® Powerpanel H₂O can be fixed to timber stud frames using staples, nails or fermacell™ drywall screws. For metal stud frames, fermacell™ drywall screws must be used. With gypsum fibreboards, a substructure-neutral “board-to-board” fixing method using staples or drywall screws is also possible. The dimensions of the fasteners, the exact spacing requirements and the consumption rates per m² can be found in the handbook: “fermacell® and Hardie® Products in Timber Construction – Planning and Installation” and in the handbook: “fermacell® Powerpanel H₂O – the Wet Room Board”.