Question Of The Month: Coating Of Fiber Cement Facade Panels

Sucking or not sucking? When coating fiber cement facade panels, the first thing to check is whether asbestos fibers are contained in the panel. Possibly existing embossings or stamps on the plates show a coding: DIN EN 492 type AT (ie containing asbestos) or DIN EN 494 type NT (ie asbestos-free). If in doubt, separate tests are required. If you can see fibers in the area of broken and cut edges that do not melt or burn when heated with a propane gas flame, you have to reckon with plates containing asbestos fibers. In such a case, all relevant safety, environmental and occupational safety regulations apply to the processing of these areas - as well as the technical rule for hazardous substances 519 (asbestos: demolition, renovation or maintenance work). Note:With the European directive 1999/77 / EG products containing asbestos were banned in principle! Fiber cement building materials for building construction made in Germany today consist of cement and fibers. The latter based on cellulose and / or alkali-resistant plastics and additives. In building construction, fiber cement panels are used as facade panels, balcony cladding, window sills and much more. In the case of renovation, a distinction must be made between normally absorbent and non-absorbent panels: absorbent fiber cement panels are primed with solvent-based or water-dilutable primers and coated with a diffusion-open paint between and finally. ZERO RenoTop Housepaint is such a highly elastic multifunctional paint that has proven itself on fiber cement. The non-absorbent sheets are mainly supplied with a colored coating, whereby this coating has a smooth, hard, UV-resistant and scratch-resistant surface. In order to achieve sufficient adhesion on these substrates, special 2-component primers - such as ZERO PUR-Haftgrund - are recommended. Further processing can then be carried out with acrylic paints or facade paints. In the case of overlapping panels, make sure that the new coating prevents the panels from sticking together! Otherwise this can lead to the breakage of individual plates. In this area, a predetermined breaking point is conveniently generated by a cut. By the way:In the case of recurring coating, the previous sd value (water vapor permeability) deteriorates due to an increase in the layer thickness and bubbles can form in the coating in ventilated facade panels (attention: reservation of concern). As a precaution, also inform yourself in BFS Leaflet No. 14.