Polystyrene concrete screed: independent base insulation

Polystyrene concrete screed is a type of ordinary cement-sand casting, and differs from it only in the presence of a filler - granulated polystyrene. Due to the presence of this substance in the solution, the thermal insulation characteristics of the coating significantly increase, because such screeds are often placed in residential premises.

Below we describe the technology of pouring concrete with polystyrene filler, and also describe its main advantages and disadvantages.

The composition of the material

For low-rise construction, not the most durable materials are often in demand, but those for which heat-saving and sound-proofing characteristics will be a priority. And one of these materials was polystyrene concrete (find out here why and how the blind is made of concrete).

The composition of the solution for it is as follows:

• The cement-sand mix is ​​used as a base. To achieve the required strength, the manual recommends using cement grade M300 and higher.
• The filler is polystyrene granules. When self-fabricating material, they are purchased separately and poured into a liquid solution.
• To improve the quality of the screeds, plasticizers and hardeners can also be added, but then the price of the coating will increase slightly.

Depending on the ratio of concrete / polystyrene, the material is divided into strength classes:

As a result, we get a fairly lightweight concrete, inside which are sealed cells with air.

Due to this structure, the material has the following advantages:

• Low thermal conductivity. Polystyrene acts as an insulator, because to pass heat such a floor will be much slower than that made from ordinary concrete.
• Good sound insulation qualities. Uneven density (alternating layers of concrete and polymer) leads to the fact that the volume of the transmitted sound is very much reduced.
• Low weight. Porous granules in the thickness of the screed significantly reduce its density, because it puts less stress on the supporting structures.

If we talk about the shortcomings, then it should be attributed to them except that less, compared with solid concrete, strength. On the other hand, such a coating is easier processed by conventional tools, so that if necessary, we will not need to cut the concrete with diamond circles.

Pouring technique

Tools and materials

Such screeds are used in housing construction widely enough. One reason for their popularity is relatively simple casting technology.

If you plan to level the floor with your own polystyrene concrete mix, then you will need:

• Large capacity (minimum 20 liters) for solution preparation.
• The electric drill with a nozzle mixer.
• The rule for leveling large surfaces.
• Level.
• Light beams.

The list of materials will be typical for such works:

• Cement required brand.
• Granulated polystyrene, which can be purchased in most building supermarkets in the most different packaging.
• Modifiers for cement slurry, improving its fluidity and shrinking polymerization.

Tip! For maximum savings, you can make the filler, crushing the old foam plates, but then the quality of the material will decrease significantly. And such preparation will take a lot of time.

If finances allow, you can purchase a ready-made composition in which porous granules are already mixed with sand and cement in an optimal proportion. Such compositions include mixtures under the brand name Polybeton and their analogues.

Preparation for work

We begin the work with the preparation of the foundation:

• From the floor we remove the old coating and dismantle the coupler. We should have a flat concrete slab.
• In advance we lay channels for communications inside the floor. If necessary, we perform diamond drilling of holes in concrete and install mortgages for cable channels and pipes.
• We clean the surface of the slab of dust and debris, treat it with waterproofing mastic or lay the moisture-proof membrane.
• On the perimeter on the wall we glue the damper tape. It not only saves the screed from cracking when temperature drops, but also reduces the level of sound transmission between adjacent rooms.

Then prepare the solution:

• For laying the floors in the same room it is better to mix small portions - then we will be able to provide an acceptable quality of the composition at home.
• Mix dry ingredients. To prepare the solution for the purpose of thermal insulation of floors on 1m³ polystyrene will need about 160 kg of cement.
• Pour 10 liters of water into the container and add 20 ml of dishwashing liquid with anti-greasy effect or a special plasticizer (choose the volume according to the manufacturer's recommendations).

• Pour the dry component into the water and mix with an electric drill until the solution acquires the consistency of thick sour cream.

Floor fill

It remains only to fill and align the tie:

• On the basis of the set beacon rails, aligning them in the same plane. For fastening beacons it is convenient to use slides of a more abruptly mixed solution.

• To ensure the most effective thermal insulation, beacons should be placed approximately 50 mm from the level of the base plate.
• Then we begin to fill the screed, gradually moving from the far corner to the door. The flooded surface is immediately leveled with a rule dipped in water.

Tip! It is very convenient to work together: while you are leveling up the freshly fired area, your partner is preparing the next batch.

• We flood the walls with a spatula as quickly as possible: the solution retains its fluidity for no more than half an hour, so that it will take an effort to remove the cement.

• After pouring, we provide the coating with an optimal mode for drying. The room temperature should be about 15-25⁰C and low humidity. Drafts and temperature fluctuations can lead to cracking of the filled layer.

Conclusion

Стяжка пола из полистиролбетона обустраивается довольно просто. При этом покрытие получается достаточно «теплым», что способствует повышению комфорта в доме, а также позволяет экономить на обогреве (см.также статью «Пескобетон для стяжки: практические рекомендации»).

Fill technology is shown in more detail in the video in this article.