Underlay for floor screed

In order for the final result of the work to meet all the necessary requirements, the actions taken must be carried out in strict accordance with the rules. This applies without exception to all stages of work, even those that may seem less significant than the others. For example, the substrate under the floor screed, for all its apparent insignificance, plays a rather important role, and therefore it is necessary to consider this issue separately. This will be discussed further.

Purpose

First of all, it is necessary to determine what tasks are assigned to the substrate and why it is needed.

• The substrate under the concrete screed can be laid as a waterproofing barrier. The idea is that the concrete mix that makes up the screed contains a certain amount of moisture. If the base is concrete, then in principle there are no problems with this, but when the screed is on top of the wooden base, then the base will not be separated from the screed.
• The second case of application of the substrate in this capacity is the variant when the screed is performed on top of the earth base. The fact is that in this case it is necessary to isolate the coupler already, since the base will always be slightly wetter, which over time may lead to the loss of the operating characteristics of the coupler.
• Among other things, the substrate can be laid for sound insulation of the floor. In this case, an appropriate material should be used, for example, a cork substrate with good noise absorption.
• Substrate under the screed should be used in cases where there is a need for additional floor insulation. Foam plates, which are impervious to moisture and have good thermal insulation performance, are also well suited for these purposes.
• Do not do without laying the substrate under the screed in the case of installation of a heated floor system. It is better to use a substrate with foil, which will prevent heat loss and at the same time serve as waterproofing.

Piling

As can be seen from the above, laying the substrate under the concrete screed is quite a desirable point of repair work. As for the process itself, it does not pose any difficulty. The selected material is simply laid on the base. If we are talking about roll materials, it should be noted that the laying of individual sheets of the substrate should be carried out with an overlap of at least 10–15 cm. Additionally, all these places should be taped.

Note! If you use some kind of plate material such as polystyrene foam or foam, then lay it end-to-end, evenly over the entire surface. For additional insulation, the joints should be taped.

Whatever material is used as a substrate for the screed, it must be laid strictly evenly and tightly. There should not be even the slightest gaps through which moisture could penetrate, since it is precisely at this point that the screed failure and the formation of cracks will continue to occur. Especially when it comes to holding the screed on top of the earthen base.

In conclusion, it should be added that the question of whether to use a screed substrate should be addressed privately. In principle, it is possible to carry out the screed without the use of additional materials, and in some cases, for example, when the screed is planned over concrete, this is permissible, but in order for the screed to perform its functions as long as possible, you should not neglect this stage of work. . In addition, the substrate has a number of its operational characteristics, which will be quite desirable.

Video

This video will introduce you to the technology of laying the concrete substrate of the floor on the ground: