Insulation of the floor: how to insulate the floor of the first floor effectively, reliably

Comfort in the house is, first of all, warmth. Living on the ground floor, whether it is a private house, apartment, housing over an arch or over an unheated room, floors often cause discomfort and other serious problems. This is cold, high humidity, the annoying smell of damp at any time of the year, and especially in the dank off-season and, as a result, endless colds of the whole family. Proper insulation of the floor during repairs or even at the stage of building a house will save adults and even small children from any of these problems from now on..


  • Comprehensive solution to three problems
  • Classic Log Flooring
  • Wood concrete floors
  • Prefabricated Dry Flooring


Comprehensive solution to three problems

The problems of cold, high humidity and the smell of dampness should be solved in a complex. In order for floor insulation on the first floor to fulfill its main function, it is necessary to carefully seal holes, cracks and joints in the concrete floor slab, as well as at the places where it joins the walls. For these purposes, you can use mounting foam.

Polyurethane foam is an excellent heat insulator, and expanding, it perfectly fills any smallest irregularities and seals even through cracks. In addition, it is lightweight and does not create an additional load on the ceiling. Processing with mounting foam around the perimeter of the room of all joints and cracks will allow you to get rid of the smells of dampness and mold from the basement. Excess dried foam must be cut with a sharp knife..

To get rid of high humidity in the apartment on a concrete base of the floor, it is necessary to lay a layer of moisture and vapor barrier. This can be roofing material, glassine, a plastic film or any other modern vapor-insulating film material. Insulating material sheets are lapped over the entire area of ​​the room by 15-20 cm overlap. The lap places are glued with bituminous sealant and fastened with a construction stapler, and the film sheets are wound on the walls to a height of 18-20 cm.

Floor insulation - a comprehensive solution to three problems

Before insulation on a concrete floor base, it is necessary to lay a layer of moisture and vapor barrier.

The next stage is the insulation of the concrete floor of the first floor is carried out according to one of the following options:

  • Classic floors on logs;
  • Screed from sawdust concrete – wood concrete;
  • Prefabricated Dry Flooring.

Classic Log Flooring

Logs made of wood are laid on the floor on a vapor barrier with a pitch of 500-600 mm, usually parallel to the shortest wall of the room. They are attached to the concrete base of the floor with special anchors measuring 8-10 x 200-250 mm. In the space between the lags lay layers of insulation, usually mineral wool, less often – foam.

For cold and humid conditions of the first floors, mineral basalt wool is better than other heaters: it does not burn and is practically non-hydroscopic.

It is recommended to use fiberglass for insulation only under the condition of very carefully made vapor-waterproofing. This material is too hygroscopic..

Polyfoam as floor insulation the ground floor is almost never used due to non-compliance with fire safety requirements, in addition, rodents can bite it.

Expanded polystyrene is the most expensive insulation, but its use is justified if it is necessary to ensure the thickness of the insulation layer is less than 50 mm.

Classic Log Flooring

Log floors – traditional construction for insulating the ground floor

After laying the insulation on the logs, a draft floor of a grooved pine board is laid and, finally, any finishing coating: parquet, laminate, tile, linoleum or carpet. When choosing a floor option for logs, it should be noted that its thickness is about 7-10 cm and in rooms with too low ceilings it is not always acceptable.

Wood concrete floors

Arbolit or sawdust is a very popular in the recent past, but undeservedly forgotten cheap, light and durable material for floor insulation. It is also called wood concrete and orgabeton. The mixture is prepared from sand, cement and sawdust, adding chemical additives nitrate or calcium, water glass for mineralization. The benefits of arbolite are undeniable:

  • High thermal insulation;
  • Small specific gravity;
  • High strength
  • Environmental friendliness;
  • Does not burn;
  • High bending strength;
  • High degree of sound insulation;
  • Convenience in processing;
  • Very low cost.

But this material has two significant drawbacks:

  • Layer thickness 100-150 mm;
  • Long drying time without chemical additives – 22-25 days.

Given the significant thickness of the sawdust concrete layer, it is possible to insulate floors with this material only in rooms with sufficiently high ceilings. Fill the mixture with two layers.

For the first, thicker level, a mixture is prepared at the rate of one part of cement M400, two parts of medium-sized sand, six parts of sawdust and pour an even layer of 70-80 mm thick.

For the second level, which serves as the final screed, one part of cement M400, two parts of sand, three parts of sawdust are mixed and poured with a thinner layer of 20-25 mm.

Wood concrete floors

Arbolit – a cheap, lightweight, durable mixture for floor insulation on the ground floor

After solidification in 3-3.5 weeks, parquet, laminate or any other floor covering can be laid on arbolite.

Prefabricated Dry Flooring

This type of floor based on dry leveling mixtures and gypsum fiber boards is called a dry screed, it is easy to install, is water-free and, thanks to a coating thickness not exceeding 50 mm, is suitable for rooms with low ceilings.

Prefabricated Dry Flooring

Dry screed – a modern and effective way to warm the concrete floor

A layer of fine expanded clay or quartz sand is poured onto the vapor-moisture insulation layer, leveling the filling with a long level and, if necessary, slightly tamping.

Two layers of moisture-resistant gypsum fiber sheets are laid on top of the expanded clay backfill, fastening them together with dowels. You can also use sheets of moisture-proof plywood used in the construction of yachts – this is a very durable and wear-resistant material that practically does not deform. If KNAUF Superfloor panels are used, a single layer is sufficient: they initially have a double thickness. It is advisable to glue the sheets of coating material between each other, and to putty the seams with a dense putty for external work for strength and guaranteed moisture resistance.

Modern German technology of dry prefabricated floors is rapidly gaining popularity, thanks to many advantages:

  • Excellent thermal insulation;
  • Moisture resistance;
  • Soundproofing;
  • Simplicity and speed of installation, which does not require special training;
  • Cleanliness in work;
  • Suitable for laying not only on concrete, but also on a wooden floor;
  • Light weight.

On a dry prefabricated floor, you can walk immediately after installation and lay the finish flooring – parquet, laminate, linoleum or floor tiles.

Listing the traditional methods of warming floor structures of the first floors, it should be noted the most modern and most effective systems – water and electric and infrared warm floors. Water heated floors are not recommended for use in multi-storey buildings due to possible leaks, but this prohibition does not apply to apartments on the ground floors. Electric heated floors are easy to install, but their operation is expensive. It doesn’t matter which type of floor insulation you choose, the most important thing is that your abode on the ground floor will be filled with warmth and comfort.


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