Timber stud walls

Clay building boards with a thickness of 22 mm can be easily and rationally applied to an interior wall that has been appropriately gridded with wooden studs, as well as in roof slopes and ceilings. Metal profiles are also suitable for fastening, provided there is additional transverse stiffening. The centre distance of the substructure should be 31.25 cm or 62.5 cm for the clay building boards. If studs or rafters are present, the load-bearing battens are dimensioned accordingly. The load due to the additional application of the plaster must be taken into account. The 16 mm clay building board always needs a full-surface wooden substrate, such as formwork made of rough sheet piling.

Clay board 22 mm

Masonry walls

The clay building board is also ideally suited for application on flat substrates such as concrete, sand-lime brick and brick walls and wood-based panels. Here, it can usually even be simply glued on. Both the 16 and 22 mm boards can be used on partition and interior walls, and the 16 mm board can be used on ceilings and in sloping roofs..

The clay building board can also be used on old plaster substrates: This way, damaged, uneven walls get a straight surface again. Larger defects must be repaired with clay base plaster and sufficiently dried before installation. By the way, clay building boards can also do a wonderful job as a moisture regulator in bathrooms (outside of wet areas), thus preventing mould infestation.

Clay base plaster

Installing clay building boards

Clay boards are very easy to install on the prepared substrate. Various types of fastening are available for this purpose: Corrosion-resistant screws and wide back staples on wooden substructures, on flat substrates the panel can be glued. The panels can also be fastened to a wooden substructure (grid or full-surface) with a pneumatic tacker and suitable wide-back staples . This is particularly quick and efficient. On sloping roofs it is absolutely necessary to additionally screw the panel. Here, the board can be fastened quickly with the stapler, then secured with the screws.

The panels are now fixed with screws and retaining plates or staples. On flat, load-bearing, vertical walls, the boards can be easily glued with clay adhesive and reinforcement mortar. The joints of the edges must be fixed with an offset of at least 25 cm. At door and window reveals, make sure that the board is cut out in an L-shape at the corners. At the panel joints, the screws are either placed with a 2 cm edge distance or screwed into the joint using a retaining plate (not on ceilings and roof slopes).  

Heating, gas and water pipes can be accommodated as usual in dry construction. Socket openings are also sawn out as usual with the hole saw. If only pictures, lamps and other light objects are to hang on the walls, fastening with screws and dowels is sufficient. For radiators, wall cabinets and similar heavy objects, the substructure must be equipped with correspondingly strong wooden slats.

Clay adhesive and reinforcing mortar

Mounting the clay boards

Once installed, clay building boards can be worked on straight away.
The boards are lightly moistened with a sprayer and skimmed with  adhesive and reinforcing mortar. A reinforcing mesh is embedded across the entire surface of the applied plaster.

Reinforcing mesh

Once the wall is completely dry, it can be plastered with clay fine plaster in a thickness of 2 - 3 mm. It is possible to apply a facing plaster or finishing plaster . Here you can decide according to your own surface requirements. If the substrate is made of OSB boards, make sure that the plaster is applied as thinly as possible on the board. A lot of moisture due to thick plaster layers can deform the boards, as the moisture cannot be released to the substrate, and can thus lead to tensions in the board. After the plaster has dried to a leather-hard consistency, it can be sponged, rubbed or smoothed.

Clay paint or clay brushed plaster can now be painted onto the clay fine coat plaster as well as the clay fine-finish plaster. All of the above-mentioned surface products support the outstanding room-climatic properties of clay building board and clay plaster.

Fine clay plaster   

To the brief instructions