What screed knows everyone, but not everyone understands the need for it.This intermediate layer is the basis for the finished floor, its quality depends on the service life of the surface coating.To align the bases of stone, brick and concrete, when the level difference is between 20 and 60 mm, apply a cement-sand screed.With it created the basis for the device floor coverings of various kinds.
Benefits
worth noting resistance floor with cement coating to water, mineral oils, organic solvents and other substances.Specific maximum pressure that the cement-sand screed is able to withstand is 600 N / sm.kv..It can also easily transfer the average intensity of traffic with rubber tires.With regard to impact resistance, it is characterized by the absence of any chips from falling objects with a weight of no more than three kg.Because of these properties, it can be used to perform the tie in offices, homes and warehouses, commercial and industrial areas.
composition of cement-sand screed consists of the following ingredients:
- small fraction sand;
- cement (usually Portland cement);
- modifiers (plasticizers different regulators shrinkage);
- spetsnapolniteli.
Through using fiberglass reinforcement, you can forget about the usual strengthening of the floor steel rebar.As regards modifying additives by the use change physicochemical characteristics of the mixture and increase the frost resistance and ductility of the screed.
addition of plasticizers helps to reduce water separation and peelability mortar reduction in the rate of hydration, also allows setting cement in the initial stages of curing, thereby obtained a more fine-grained and homogeneous structure.Cement-sand screed based on Portland cement can be activated as a waterproofing and corrosion-resistant layer.It will ensure protection of concrete foundations.
thickness
screed floor heating should not be thinner than 5 cm;if present in the composition of plasticizers, it is not less than 3 cm. When you perform over a wide area is to use special units, the use of which contributes to a significant reduction in time and effort.There are several factors that affect the thickness of the screed:
- the presence of the insulation layer;
- the degree of smoothness of the base;
- type of flooring.
insulation
Running it dense materials capable of carrying the load, such as mineral wool or polystyrene.For use in screeds density of mineral wool should be at least 150-170 kg / cu.m., And the density of styrofoam - not less than 35. Various heat insulating mound (foam glass, perlite, penolistirol), glass used on the floors, which are made on the joists.You can use expanded clay litter, but, compared with polystyrene, it is less effective insulation, and to obtain the necessary factor to do about 30 cm backfill.
