A strong and smooth surface under the floor is called a screed. Special constructions and solutions are used to eliminate curvatures, cover communications, create the necessary slope, load distribution. Scaffolding is performed on the covering overlap to strengthen and insulate the floor. Norms and requirements for the arrangement of the floor are enshrined in special State building codes.
Experts distinguish several types of screeds on different principles:
1. Linking with the floor. If there is adhesion of the screed to the work surface (often through the effect of adhesion), then this option is called connected. When separating the screed from the waterproofing and thermal insulation layers, but in contact with the walls, this type is called screed on a separate layer. And in the absence of adhesion of a layer to walls - floating.
2. Method of laying: a continuous layer, with the possibility of a mixture of self-leveling, semi-dry and prefabricated dry. The latter involves backfilling with bulk materials (expanded clay) with subsequent placement of gypsum fiber boards.
3. Features of the structure. Industrial is made using high-strength brands of concrete. And semi-dry cement-sand can be made with the addition of synthetic fiber.
Technologies can be divided into mechanized and manual. The main mixtures for screed are anhydride (based on calcium sulfate, also called "gypsum") and cement-binder.
Popular lightweight concrete screeds are performed in several stages:
If the work is performed in the winter, the bottom layer should be heated to + 50C.