Repair & Renovation Guide 149 7.9 Appearance of lap marks on the painted surface (e.g., by stopping and resuming painting on the same surface(s) at different times) POSSIBLE CAUSES It may be caused by the cracked substrate (plaster) of the surface trying to paint. The cause also, may be the application of matte paint on a gloss surface. Also, it is possible that a coat of paint was applied over a previous coat that did not have the time to dry sufficiently. It is also possible that a coat of «hard paint» was applied over a substrate that has greater flexibility (elasticity) than the one on the finished surface. SOLUTION To avoid such problems, it is very important to know from the beginning that the substrate of the paint and the final coat will have identical properties and compatibility as materials. Also, the sufficient time between successive coats of paint must be allowed. If the problem already exists, the entire coat of paint must be removed. Continue by sanding the substrate thoroughly to even it in its entirety, clean thoroughly, prime and repaint the entire surface. 7.10 Growth of mold and microorganisms on a painted surface POSSIBLE CAUSES • Paint on a surface already affected by mold and microorganisms, without the proper procedures for their removal. • Moisture or water leaks on painted surfaces or their substrates. • Moisture penetration through the wall(s) or the roof. • ‘Contamination’ of the paint from materials used for the skimming of the surface. • Surfaces without exposure to sunlight. • Water vapour that condenses. • Surfaces that are near gardens. SOLUTION It is always a good practice, before starting painting on a surface to clean it thoroughly with anti-mold products. Clean water should always be used for the preparation and possible dilution of the skimming paste. The solution of the problem is achieved, depending on its extent and the possibilities of intervention that we have in the space, as described in PROBLEM - SOLUTION 2.3. 7.11 Disintegrating paint and substrates (plaster/render) from moisture attack SOLUTION Identify the cause that has created the disintegration and take the necessary steps to treat it. • Continue by removing the loose plaster in sections or completely if deemed necessary. Replaster the surface and allow for it to dry completely. • Waterproof the wall surface in its entirety with the flexible mortar WATERPROOF MORTAR (p. 273) in order to protect (the wall surface) from future moisture penetration into the plaster. • Complete the repair by priming and repainting with the acrylic paint 100% ACRYLIC (p. 273), 10 YEARS WARRANTY (p. 281) or the polyurethane-acrylic hybrid paint DUROPAINT-PU (p. 251).
RkJQdWJsaXNoZXIy MTk0OTg2