For quality of a plaster covering the great value has a correct choice of a solution. First of all it is necessary to consider, the building subject to furnish is constructed of what material. Porous materials - brick, concrete, from plaster plates, etc. - well absorb a moisture. Therefore in order to avoid fast drying of the put layer, solutions should be applied more liquid consistence. Knitting for them - izvest, cement and their mixes.
For wooden surfaces are more suitable alabaster knitting in the pure state or in a mix with izvestju. Concentration of solutions thanks to smaller absorbability of a moisture wood can be and more dense, than applied on porous surfaces.
At a solution choice it is necessary to consider the chemical and physical nature both knitting, and a material of a finished surface. A brick wall with cement or limy plaster, concrete with cement plaster work quite homogeneously.
Between durability of a solution and durability of a material of a plane on which it put, certain dependence should be maintained. We said already that oshtukaturivanie buildings begin only after the construction will give defined usadku. But also after such term usadka will proceed to some extent. Plaster will react to it. That is why the dependence mentioned above is necessary.
Very strong plaster at usadke and other volume changes of weaker basic material of a surface cannot change together with it, cracks, otsloenija are inevitable. Therefore durability of plaster should not exceed durability of a material of a finished surface.
It is necessary to consider and factor of temperature expansion of two co-operating - a plaster layer and the basic surface. Especially in this respect it is necessary to be attentive if it is necessary to plaster metal beams and similar designs. The closest factors of expansion, at metal and a cement mortal.
Sometimes as the reason rastreskivanija plasters wrong selection of structure of a solution serves. .