Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video Today, any person living both in an apartment and in a private house seeks to surround himself with maximum comfort ... The level of comfort is certainly related to the temperature conditions of the home. Previously, it was believed that in private, country or frame houses, it is quite problematic to create an acceptable temperature regime without special loads and costs.

Today, there are a huge number of possibilities for effective thermal insulation of buildings using modern and high quality materials. One of such materials, which appeared on the construction market not so long ago, is penoflex.

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What is Penoflex?

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video Penoflex is a heat-insulating material consisting of sheets from 20 to 100 mm in size, based on polyethylene foam. Penoflex insulation has a reflective layer, which allows it not only to retain heat, but also to withstand high humidity, mechanical stress and fire, and also act as a sound insulator.

This functionality is explained by the composition and structure of the material: a large number of sealed air pores of different sizes makes it possible to effectively resist heat loss.

An additional layer of foil reflects heat into the room.

In addition to the listed advantages, penoflex has such advantages as:

  • High level of strength;
  • Long service life (it is not subject to decomposition) ;
  • Ease of installation (it is enough to cut the material with ordinary scissors or a knife and apply an adhesive layer on the polyethylene foam, and within a maximum of 4 hours the penoflex will be fixed on the desired surface), in more detail you can familiarize yourself with the installation technique below;
  • Ease of storage - to store Penoflex insulation, you do not need to look for a special place - it can be kept in packages even outdoors;
  • Environmental safety - Penoflex is not toxic, absolutely safe, and also does not promote reproduction bacteria;
  • Penoflex is resistant to both temperature extremes and various chemical influences (except for some types of solvents, for example, acetone): it does not enter into chemical reactions with soil or building materials (including bitumen, cement , lime, etc.).


If we compare foam flex insulation with other heaters, then a 20 mm layer of foam flex insulates in the same way as 40 cm wood, 1 m 20 cm brick or 3 m 20 cm concrete.

Since Penoflex is a relatively new material, many homeowners did not have the opportunity to apply it a few years ago.

However, this should not be considered a problem, since Penoflex insulation can be installed both at the stage of building a house and during its alteration or repair.The thickness of the foam flex layers should be determined taking into account specific premises and temperature conditions in the construction region: for Siberia, the number of layers will be greater than for the European part of Russia.

Where is Penoflex used?

If we talk about those areas of construction where Penoflex can be used, then there are almost no restrictions!

Penoflex is used:

  • to protect the foundation from freezing;
  • to insulate basements, floors and ceilings;
  • for insulation of balconies, loggias, floors in buildings with a small number of floors;
  • to create an insulating layer for sandwich panels;
  • for maximum temperature preservation in pools and pipelines.
  • for the construction of roads of any scale (road, rail, runways). Here, Penoflex is used to prevent deep freezing, replaces elevated embankments in permafrost regions and resists frost heaving.

Internal insulation of the house

Let us turn in more detail to the internal insulation of the house with penoflex.

General rules for installing penoflex

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video It is necessary to prepare a flat base (here you do not need to strive for perfect evenness, since penoflex is a flexible material that, in some cases, can even hide defects and surface irregularities). After the preliminary procedures, you can put the Penoflex insulation itself. Pay attention to the fact that it is necessary to fasten the layers end-to-end, and the seams that appear should be treated with a sealant, and then glued with waterproofing tape. Experts also recommend performing the lathing during fastening, it will create a ventilation gap between the insulation, the base and the finishing material (about 20 mm.

). If there is a need, then you can fix the sheets of penoflex with glue or umbrella dowels.

1. Floor

There are several nuances when installing penoflex on the floor: for better functionality, a layer for the distribution of point loads should be created (for example, use a DSP or 2 sheets of gypsum fiber board, which must be laid apart). The resulting joints should be glued with tape or insulation, while making sure that when pouring is done, it does not end up inside.

You need to leave gaps around the perimeter, which will then need to be foamed.

Penoflex must be placed between the logs of the house, having previously eliminated the gaps and cracks (they must be putty). After that, a layer of waterproofing material is placed (the simplest option is a polyethylene film, which must be overlapped at the joints), on which the foam is glued.

Penoflex insulation can also be used between the floors of a private house, if there is a need for it.

In the event that your house does not have a basement or the floor is made of concrete, the installation of the penoflex will take a little more time.

To begin with, the floor must be leveled and waterproofed without the use of solvents ("cold" method), over the "cold" insulation, penoflex is glued to the bituminous mastic.

2. Walls

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video Pre-alignment is also not required in full. Sheets are attached to the walls, the gaps between which are treated with foam, a sealed layer of any heat-reflecting material is glued on top of the polyurethane glue, for example, it can be a regular or foil-clad polyethylene film. The joints that appear must be treated with metal tape, all these stages create the so-called "thermos effect".

3. Foundation and insulation with foam flex on the ground

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video If a decision is made to isolate the house from the ground level, you should start with the formation a layer of gravel cushion (it can be sand or expanded clay), which is well compressed and compacted. The next layer is concrete (it can be either a poured solution or reinforced concrete slabs).

Next - penoflex, on top of which an iron mesh is placed. The entire resulting multi-layer structure is poured over with concrete.


Measures for warming the foundation are best carried out at the beginning of construction work: at the first stage, a ditch is dug around the building, its depth should be about 60 cm, width - about 1m. However, these parameters depend on the depth of soil freezing in winter in a particular area.

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video The next stage is cleaning the foundation, if there are a lot of defects, you can level it with cement mortar. Next, several layers of waterproofing mastic are applied, on which insulation is glued using bitumen mastic.
If there is a need to create an insulating layer that protects against moisture, you can make a concrete coating for retaliation on top of a sand base, layers of foam flex are placed on top, which is also covered with sand.

It is recommended to lay Penoflex insulation with an overlap and in 2 layers, using a checkerboard pattern, this will provide greater insulation.

How to choose a penoflex?

Do we insulate the walls with foam flex outside and inside a private house with our own hands? Review and instruction + Video The required amount of penoflex is calculated according to special formulas, specialists will help you with this.

Each part of the building has its own view, there are five of them in total:

  • for basements / foundations;
  • for walls / plinths;
  • for roofs;
  • walls, plinths and pitched roofs;
  • for industrial / warehouse premises - with high mechanical stress.

( 1 grade, average 5 of 5 )

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