In modern construction (especially suburban), such materials for the construction of walls as foam block, slag block, gas block are especially popular. Materials are light, convenient to work and most attractive for the developer – cheap. Of course, there is, as they say, the “second side of the coin” – fragility and, partly, the toxicity of the materials. However, it will now be about the drawback that manifests itself when plastering the surfaces of the walls of such materials (especially the walls of gas blocks).
The fact is that the plastering of walls from aerated concrete or foam concrete is difficult in one factor: the surface has too much water absorption, which is why all water from the plaster solution is absorbed into the wall surface. As a result, the solution dries and is painted, and without having time to form a whole and strong plastering coating. In order to avoid this, you need to carry out special surface treatment and select the suitable mixture, which we will consider further.
Materials for the preparation of porous surfaces
Whether it is new or old surfaces, the most important thing in preparing them for plaster is to remove excessive water absorption. In Soviet times, when there were no modern acrylic primers, there was one solution: moisturizing surfaces from the hose with water until they stop absorbing excessively, after which manual or machine plaster was quickly performed with lime or cement-ledge plaster materials.
Today, when special materials appeared, everything has become less time -consuming, the main thing is to keep abreast and know the materials and technologies for their application. And the main materials for the preparation of surfaces for finishing are primers, the most common and effective of all are considered on the basis of a dispersion of acrylic resins (acrylic dispersion primers). They are also used to prepare surfaces for plaster, they also moisturize the base of the floor, before the screed is cemented sandy, in general, in all cases during finishing work.
Apply these compounds with different methods: brush, brush, roller or spray, however, the method of applying macquiller brush is considered the most effective. The most porous surfaces are primed twice, the first primer is diluted with the addition of 10-20% of water.
Materials for plastering porous surfaces
Traditional compounds based on cement or lime with cement (for external and internal work) were used recently due to their cheapness, and compounds based on one isvesting or lime with gypsum (for internal work) were also popular. It was difficult to work with them and their adhesion (adhesion to the surface) was weak, and it was extremely difficult for them to plaster walls from aerated concrete, since the surface of them very quickly pulled out water.
However, today there are various applications of dry building mixtures, the varieties of which can be performed as a screed cement sandy, and plaster of walls and ceilings. Their main advantage over traditional compositions is in higher plasticity and adhesion, which makes them convenient in work and more durable.
There are compounds with which manual and machine plaster are produced, in the second case they are even cheaper. As for the composition itself, it consists of a binder (lime, gypsum, cement), filler (fine-grained career and/or quartz sand) and, most importantly, modifiers-modifiers, which actually give them plasticity (the ability to retain liquid) and High adhesion (clutch) with the surface.