The screed represents one of the horizontal layers of the home closest to our feet, is a component of the building body that acts as support And positioning layer of the future pavement. It consists of a mixture of cement and sandlinked together by the addition of appropriate amount of waterand is essential for the generation of a final surface leveled and suitable for hosting the flooringwhich is why the technique of mixing, processing and spreading the dough.
What is the screed for
As mentioned, the screed contributes to the leveling of the final horizontation layerthat is, it actually creates the flooring support plan. This layer presents itself with thicknesses in the order of centimeters (from 4 to 8), and is basically made above a so -called layer backgroundsimilar and in some cases confused with the screed itself:
In reality, in fact, it background layer precedes the drafting of the screedit guarantees accommodation to the systems of plants (electric and hydraulic) on the ground and therefore allows you to Reduce the gap to be recovered to reach the final share to which the floor must be positioned. It also plays a fundamental role in the performance of thermal and acoustic insulation of the environments. Above this layer, a waterproof barrier can be made (vapor barrier), which will therefore act from Start surface to the creation of the real screed.
The screed contributes to the correct distribution of loads from the flooring to the deep layerswhich is why it is made by better quality concrete than the background layers (which indeed are usually lighter precisely to avoid weighing unnecessarily as a “dead” weight). Within this, we find accommodation for the floor radiants, if the thermal system of the house provides them. The application of the screed – as a layer “superficial” – It therefore needs an prudent technological definition, in relation to what will be the use of the flooring that will be made above. In fact, if we are dealing with floors that need to support important loads (for example a parking lot), then the mechanical characteristics of the screed must be more performing than traditional ones. This can happen by changing the type of cement used, that is, by varying the thickness of the layer. by inserting a collaborating metal network.
It may happen that the two layers are made with the same material and in a single solution, thus identifying a single thickness that is basically called screedeven if cases are not to be excluded in which the whole layer can be called instead background. Nonetheless, the functions of the layers remain the same.
Main types of screed and materials
Among the widespread screeds we find those made directly on site properly mixing concrete, sand and water. However, today different technological solutions are present on the market, such as the so -called self -leveling screedsor screeds made with the addition of chemical additives that drastically vary its fluidityimplicitly guaranteeing automatic leveling capacity and simultaneously reducing the necessary labor. It is also possible to use so -called dry screedssold in slabs and not needing water for laying.
Depending on the supply then, the screed can be defined pre -packaged or predicate. The first is always made on site but through Automated dosage and mixing procedures. The second is instead mixed on the pipeline, while The doses of the various ingredients are defined as priori in the sales package.
In the case of Cover horizontationthe screed also has the further crucial REPORT REPORT OF RATE WATERS: It is an indirect role, as it is not the actual screed that is in contact with water. However, in these cases the realization variable thicknessallows you to obtain a final surface with a slope setoriented in such a way as to make rainwater convey the appropriate collection systems, that is, eaves and plumbers, thus avoiding stagnation and accumulations in specific points of the roof. In technical jargon, this particular system is identified as “pendulity screed“, as in fact it is itself that it creates the final slope that will have the external surface.
