Floor insulation with isolon in a private house: under linoleum, plywood, screed

The problem of maintaining heat in a house can be solved by laying traditional thermal insulation, for example, mineral wool, expanded polystyrene or foam. They have excellent insulating characteristics, but at the same time they have to put up with serious disadvantages, such as heavy dusting and the release of unsafe styrene or toluene vapors. As an option, you can insulate the floor with isolon; the material is quite new, but has already proven itself as a leader, without bad habits.

Izolon can be laid on both wooden and concrete floors

Types of isolon for thermal insulation of floors

There is nothing new in the technology of insulation with isolon. The material has been produced for quite a long time, so insulating the floor in a private house with isolon could have been done a decade and a half ago. Another thing is that insulation was used on a large scale mainly in industrial equipment, and only recently attracted everyone’s attention with its rather interesting characteristics.

The material is polyolefin foam with an additional reflective coating of aluminum foil. Due to this, it is easily recognizable by its characteristic surface pattern.

In order to get the desired effect from the installed thermal insulation, you need to imagine what kind of isolon structure is suitable for the floor in a wooden house as insulation.

The industry produces isolon with different structures:

• The classic version of foamed polyethylene filled with a pore-forming gas agent, this includes Izolon 100 and its foreign analogues;
• Foamed polyethylene, reinforced with catalyst additive. As a result, chemical bonds appear between individual pores—cells—that improve the durability and strength of the insulation. A typical representative is Izolon 300;
• Heavy and dense PET, which has undergone special treatment by sintering at elevated temperatures and irradiation. As a result, cells are crosslinked at the physical level, without the participation of reagents. The most striking representative of this type is Izolon 500.

Important! The greater the depth of additional processing of polyethylene foam, the higher its strength, the greater the number of air cells, and, accordingly, the lower the thermal conductivity coefficient.

Brands with a soft and viscous structure perfectly absorb noise and vibrations; Izolon 100 is suitable for soundproofing the floors and walls of a building. The more internal connections between the cells, the harder the material is, and the worse the sound insulation of the floor based on isolon works.

Izolon 300

In addition, thermal insulation based on foamed polyethylene is available with one-sided foil, with double-sided foil and also with a self-adhesive base on one side.

Izolon 300

This type of thermal insulation can be considered as a universal material, equally suitable for noise control and floor insulation. The three hundredth Izolon has good noise-absorbing characteristics, within 22-25 dB. The material is able to withstand prolonged heating and constant alternating load.

Laying isolon 300 on the floor guarantees effective protection against any vibrational low- and high-frequency noise and sounds. Isolon is especially good as insulation and sound insulation on concrete floor slabs. Available in rolls, in the form of a sheet with a thickness of 5 to 10 mm.

Material marking uses a numerical index, a sequence of four digits. The first two indicate the foaming ratio of the material, usually it is 30, which means an increase in the volume of polyethylene during processing by 30 times. The second pair of numbers indicates the thickness in millimeters.

Important! A good argument for using Izolon 300 as floor insulation in a wooden house is the fact that three hundredth polyethylene foam is the main material for heat and sound insulation of modern car bodies.

The cost of insulation directly depends on its thickness, on average the price is 1-3 dollars per meter.

Izolon 500

One of the most common and widely used insulation options for walls and floors of wooden houses, stone and brick buildings. In a situation where complete floor insulation is required, “Izolon 500” is subjected to special thermal and radiation treatment, as a result of which the insulation surface is quite rigid and durable.

Material characteristics:

• The compressive strength is 0.036 MPa, which means that you can walk on the insulation laid on the floor as if you were walking on EPS. Unlike penoplex, isolon retains fairly high elasticity and the ability to stretch without destruction by 130-180%;
• The thermal conductivity coefficient is only slightly higher than expanded polystyrene and mineral wool. It is 0.031 W/m*K versus 0.028 W/m*K for competitors;
• Izolon's flammability class is at the G2-G4 level.

Izolon 500 is somewhat inferior in noise insulation and sound absorption efficiency to its closest relatives. This figure is 20 dB versus 22 dB for the 300th brand and 26 dB for the 100th.

For wooden floors, insulation with a self-adhesive layer is best suited

The material is produced in the form of sheets with a thickness of 20 mm to 100 mm. Polyethylene foam can be easily cut and cut into any configuration for installation both on the screed and between load-bearing floor joists. The cost of Izolon 500 is 40% higher than that of the three hundredth brand.

The presence of full aluminum foil instead of a metallized lavsan coating, like penofol or polyisol, guarantees high thermal resistance when heated and at the same time provides almost complete, at the level of 97%, reflection of radiant heat.

What to choose for a specific situation

There is no universal recipe for using isolon. For example, for laminate flooring, it is recommended to use a 25 mm thick sheet for insulation and sound insulation. If the room is heated with infrared heaters, then insulation with a foil screen can be installed.

For interfloor ceilings, especially in modern houses where the floors are made of concrete slabs, it is recommended to use dense isolon 500 with a thickness of 8-10 mm. If you plan to install a heated floor in the room, then it is best to use double-sided foil-coated insulation material up to 10 mm thick.

Isolon may be inferior to mineral wool in terms of insulation efficiency, but there will definitely be no problems with it due to water, condensation or pathogenic microflora

A similar material can be used under classic concrete pouring or in a dry backfill screed. For insulation along joists or in two-layer versions using mineral wool, Izolon with a thickness of 20 mm and above is used.

Material composition

Izolon is based on foamed polyethylene, having a thickness of 2 to 100 millimeters. At the same time, isolated air cells make this material an extremely weak conductor of heat, which makes it possible to insulate the room even at this expense. With sufficient thickness, of course. The foam base is covered on top with aluminum foil, which can be located on one or both sides of the material.

The material can also be used when insulating an external wall from the outside, located between the wall structure itself and the external decoration in the case of using curtain panels. In this case, the heat from the wall in the form of the same infrared radiation does not escape into the external environment. The proportion of reflected heat is very high, approaching 98 percent.

Specifications

• Material density - 19-200 kilograms per cubic meter;
• Sound absorption – up to 68 percent;
• Operating temperature from -80 to +80 degrees Celsius;
• Water absorption – up to 1 percent.

The last parameter means the material’s high resistance to humid air and water, which greatly expands its scope of application. This area, by the way, is really very wide: insulation and soundproofing of walls in apartments and private houses, floors (including self-leveling ones), interfloor ceilings, balcony structures, as well as non-residential premises. The material exhibits its properties well when insulating wet rooms with large temperature differences, such as baths. Finally, the material is used for pipe insulation, the production of workwear, as well as the manufacture of climate control and refrigeration equipment, but we will not touch on this.

Which side should I place the isolon on the floor?

Experts advise in any case to carry out insulation with the foil surface directed towards the inside of the room. In this way, it is possible to block the leakage of radiant heat and at the same time strengthen the vapor barrier of the floor.

An exception may be a scheme with two-layer insulation of plank floors on wooden logs, provided that water heating is used in the house. For example, when laying the bottom layer of mineral wool, you can lay foil-coated polyethylene foam with aluminum foil to the mineral wool. This is done in order to block the seepage of supercooled water vapor through the layer of polyethylene foam insulation. The foil perfectly traps vapors, prevents moisture from condensing and forces it to escape through the air gap between the isolon and the mineral wool.

Let's sum it up

Insulating the floor of a log house is a very responsible job. The comfort of living in the house will depend on how correctly and efficiently it is done, so it is best to entrust it to specialists.

will help make your home warm and cozy. We have been providing finishing and insulation services for wooden houses for more than ten years and have accumulated vast experience in this area, which we want to share with you. We will be happy to provide our services to residents of Moscow and the region. Leave your requests, and we will send a specialist to you for free to inspect and draw up a preliminary estimate of the work.

On the Contact page you will find detailed information on how to contact us.

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How to attach isolon to the floor

It is clear that the method of fixing the insulation depends on the nature of the base. Foamed polyethylene, even with great thickness, remains a plastic material. Therefore, it is impossible to lay Izolon on the floor using point fastening with self-tapping screws or metal brackets. Under load, isolon can break at the fastening points.

It is best to lay the insulation on an adhesive basis, and the glue should not dry out. These can be viscous oil mixtures, silicones, but it is best to use self-adhesive polyethylene foam or double-sided construction tape with a metallized surface.

Sequence of work during insulation

First of all, you need to decide on the thickness of the material, which depends on the availability of free space and climatic conditions. In cold regions, the insulating capabilities of isolon may not be enough, and it is better to use thicker layers of traditional insulation for this.

The leaves must be laid end-to-end, trying to avoid the appearance of gaps. To prevent this when finishing complex surfaces, you should carefully measure all the parameters and cut off the fragments with a high-quality sharp knife. In this case, the joints between the sheets are closed with aluminum tape, which also ensures the reflection of infrared rays.

In this case, empty space should be left between the isolon and further finishing, since otherwise condensation will collect on the material, which has mediocre vapor permeability.

Important! Do not place this foil material in close proximity to electrical wiring, as aluminum conducts electricity.

As for fasteners, many models of such insulation have a self-adhesive base, which allows you to radically simplify the process. If this element is not there, then the ideal solution would be to use acrylic-based adhesives or those marked No. 888.

How to attach isolon to a wooden floor

A slightly different scheme is used when laying the panel on a wooden base. If you need to insulate a plywood floor, it is best to lay insulation without fixing it to the base. Only the joints between sheets or panels are sealed. This method is recommended for a wooden base under flooring in the form of linoleum or laminate.

When laying isolon on joists, fixation is performed using staples, glue and wooden slats.

Manufacturers: list of verified brands

You need to select an adhesive for gluing penofol to concrete based on the type of surface where the material will be installed. For example, heat-resistant compounds are used for lining a sauna, and products that are frost-resistant and hydrophobic are used for exterior work. When choosing an adhesive for internal use, you should read the quality certificate to confirm the safe properties of the product.

The list of high-quality adhesive compositions is presented in the table:

Preparing the base

Unlike penoplex, polystyrene foam and even mineral wool, Izolon is quite sensitive to mechanical load, so the material can only be laid on a flat horizontal surface. Especially if the flooring is supposed to be laminate or, even worse, linoleum. In this case, the height difference in a one-meter area should not exceed 2-3 mm, and in principle there should be no bumps and depressions.

The concrete floor must be cleaned of loose “cakes”, dust and dirt must be removed. We carefully knock down the cones with a hammer and chisel, and clean off the remains with a grinder. Any depressions must be filled and smoothed to floor level. Next, it is advisable to wash the concrete and cover the floor with a primer. Not with paint, not with varnish, but with a primer for concrete.

Important! Additional treatment does not affect the insulation of concrete with isolon, but the concrete surface, even if covered with thermal insulation, will mercilessly collect dust. This is especially true for thin screeds.

When people walk on the floor, the Izospan cloth will work like an air pump, and all the dust will slowly move from the surface to the walls, and then get inside the room through the baseboards.

Completely worn-out floors need to be overhauled before insulation; a new screed may have to be made. It is impossible to lay Izolon on a surface full of cavities and cracks; under load, the glued panel will separate into separate sheets or strips.

If you plan to insulate the floor with isolon in a wooden house, then first you will need to remove the old floor covering, clean or sand off the paint, and treat the wood with a bioprotective solution. The floorboards are wedged together with wooden inserts, but the cracks cannot be completely sealed, otherwise the floor will rot under the insulation. After sanding, they can be selectively blown out with foam.

Plywood floors are prepared in the same way as concrete floors, you just need to additionally check that all the sheets lie on the base without “popping” or “bubbles”. Holes are drilled in problem areas, foam is blown in and immediately loaded with pressure weighing at least 10 kg.

Sequence of work during insulation

When working with isolon, you must adhere to the basic rules of installation and operation, which will allow the insulation to last longer, performing its duties efficiently.

Insulation of ceiling and floor with Izolon

This material has a small thickness, therefore, in order to obtain a high-quality thermal insulation cake, it is often combined with other insulation materials, for example, mineral wool.

The ceiling insulation method consists of the following steps:

1. Mineral wool is laid between the ceiling joists.
2. Isolon is attached stretched along the joists.
3. They stuff the counter-lattice.
4. Apply the finishing touches.

Isolon can serve as a sound insulator, for which it is placed directly under the finish. In this case, the material is attached end-to-end to the working surface using a construction stapler.

Note! If possible, it is better to leave a gap between the isolon and the finish necessary for the evaporation of moisture.

When insulating the floor with isolon from the inside, the work order looks like this:

1. Dismantling the old coating. If insulation is carried out in an old house, then first of all it is necessary to dismantle the existing floor covering.
2. Preparing the base. At this stage, the underlying structures are restored: the cracks are sealed, a new screed is poured.
3. Installation of floor waterproofing. The base is coated with a primer. After it has dried, the surface is covered with plastic film or a waterproofing membrane. Coating waterproofing can also be used.
4. Laying a thermal insulation layer. Sheet or roll insulation is adjusted in size so that it covers the entire surface. The joints are sealed with foil tape - there should be no gaps at the bottom, as they significantly worsen the thermal insulation properties.
5. Waterproofing material is laid on top of the isolon and a fine finish is provided.

Note! If necessary, double-layer insulation is installed.

Wall insulation with Izolon

As a rule, such work is carried out using additional insulation - mineral wool.

Order:

1. Wooden blocks for the future counter-lattice are attached to the wall.
2. Mineral wool is laid between the bars.
3. Foil-coated isolon is nailed on top of the bars. Its shiny side should be directed towards the room.
4. The rolls are laid end to end. Existing cracks are covered with aluminum tape.
5. The counter-lattice is nailed.
6. The trim is attached.

Additional Information! A gap of at least 15 mm should be left between the finishing material and the foil.

How to properly lay foil-coated isolon on a concrete floor under linoleum

Oddly enough, many problems arise with the alignment of the panel. Izolon is usually purchased and stored in rolls; when it comes to laying insulation, the sheet unrolled on the floor acquires a wavy surface. You shouldn’t even try to stick such a “wave” evenly; the isolon will need to be laid out on the back side on the floor, slightly stretched and pressed along the edges with a light weight. After a couple of days, the isolon will become almost flat.

Next, we install the insulation according to the following scheme:

• We lay a waterproofing film on the floor. The procedure is mandatory for basement rooms and rooms on the first floor. For apartments, waterproofing on concrete floors can be omitted and replaced with a primer;
• Using a tape measure, measure the distance between the opposite walls of the room and cut off the Izolon strip with a margin of 10-15 mm. Knowing the width of the insulation roll and the dimensions of the room, we cut the required number of strips. Each time before cutting a new panel, we measure the length along the floor from wall to wall;

• We lay insulation on the floor along the starting wall. We are trying to adjust it so that the side edge of the canvas fits as tightly as possible to the wall. We lay the rest on the floor end to end, but without gluing with tape. Typically, one of the Isolon strips will have to be cut to fit into the overall width of the room;
• Place double-sided tape on the floor along the wall and lay the first strip of insulation on it. After leveling, we attach the remaining edges of the panel to the floor in a similar way. We add the remaining strips of Izolon to those already laid and connect them with tape;
• We lay fiberboard sheets on top of the insulation.

Due to the low strength of Izolon, you should not walk on the insulation; even without shoes you can easily damage the material. Therefore, when carrying out insulation work, it is necessary to use several small sheets of fiberboard, on which they move around the room.

Next, we lay the wood-fiber board, and glue the sheets together at the joints with mounting tape. It is impossible to glue fiberboard directly onto Izolon or lay linoleum on insulation without an intermediate layer. If the thermal insulation thickness is more than 8 mm, then plywood will have to be used instead of fiberboard.

How to lay isolon under OSB, plywood on a wooden floor

Thermal insulation procedures for plank and plywood floors are slightly different; in the first case, you will have to do thorough preparation to avoid damage to wooden parts, joists and supports. Thermal insulation of a plywood floor is somewhat simpler, but this reduces the height of the ceilings of the room.

We insulate the plank floor

The first step is to remove the floorboards. The boards are carefully unfastened, inspected, rejected or repaired.

Floorboards need to be removed

Only the joists will remain on the floor. If the beams are simply laid on a concrete base, then the procedure for laying Izolon is significantly simplified.

You will only need to lay insulation in the space between the beams. If the logs of the plank floor are raised above the ground on supports, then before laying the insulation, the beams will need to be hemmed with a plank on the cranial blocks, otherwise there will be nowhere to put the thermal insulation.

The general insulation scheme is as follows:

• We remove dust and dirt with a vacuum cleaner, treat the beams with an antiseptic impregnating solution and dry for at least two days;
• We cut Izolon sheets individually, according to the measured distance between the beams;
• If there is additional insulation with mineral wool under the Izolon layer, then first we lay a vapor barrier, then mineral wool, and only then sheets of polyethylene foam and always with staggered seams.

Izospan V or Izolon 100, 2-3 mm thick, can be laid on top of the beams. In both cases, the material is secured with a stapler and glued with tape. The thickness of the main insulating layer must be at least 50 mm.

Laying thermal insulation on a plywood base

First of all, you need to lay a beam on the plywood; it will act as a load-bearing frame that absorbs loads and protects the insulation from loads. The bars can be attached to plywood sheets with self-tapping screws using a vapor barrier film or without it, if the wooden base has been pre-treated with varnish.

The next stage is to lay Izolon between the bars. It is best to use sheets 20 mm thick; the thermal insulation is pushed between wooden guides and connected with tape.

A vapor barrier needs to be laid on top of Izolon. This solution reduces moisture absorption and deformation of the timber in the autumn-winter period. You can sew plywood or OSB on top.

How to lay Isolon under a floor screed

Very often, tiles, ceramics or any other floor coverings that require a sufficiently strong and rigid supporting surface are laid on an insulated concrete base. Isolon is an excellent type of insulation, but it is not strong enough, so it will need to be hidden under a screed.

Installation of thermal insulation under a concrete screed is carried out in the following way:

• We lay a waterproofing membrane on the subfloor, be sure to overlap the edges onto the walls to a height of at least 20 mm at the level of the final floor covering;
• We glue the joints between individual pieces of waterproofing twice, the first time with tape during installation, the second time with a primer, before laying the Isolon-based insulation;
• We roll out the roll into sheets and immediately lay the insulation on top of the waterproofing. Moreover, we change the laying direction to 90°. The edges of thermal insulation must also be laid on the walls with an allowance;
• Next, we install the reinforcing mesh; it will need to be raised on chips above the surface of the foil Izolon to a height of at least 20 mm;
• We install beacon chips on the insulation and fill the screed with a cement-sand mixture. The thickness of the screed must be at least 40 mm for insulation up to 10 mm thick. With a larger layer of thermal insulation, the layer is increased to 50 mm;
• After 4-5 hours, the chips are pulled out and the holes in the concrete are sealed.

The edge allowance for waterproofing and insulation is trimmed and fixed with a stapler. The gap is filled with foam and carefully trimmed. All that remains is to glue the tiles and nail the baseboards.

Warm floor on isolon, dry-laid under laminate

Manufacturers: list of verified brands

Penofol can be glued to concrete using different compounds; there are several manufacturers on the market offering proven substances.

The best options for compositions for gluing penofol to concrete:

• Weicon Easy-Mix PE-PP 45 is a two-component adhesive that provides high quality fixation. The base is methyl acrylate.
• Moment is a two-component sealant, prepared from two substances according to the instructions, and must be used within the specified time.
• Tilit - suitable for joining seams, but can also be used for gluing sheets.
• Titanium is an easy-to-use, lightweight composition that exhibits high adhesion to concrete, one-component, and adheres well to foil-coated foam.
• Ceresit (CT83) is a universal composition for all types of surfaces.

• Atlas Stopter K-20 kley – exhibits high technical characteristics and provides a high-quality connection.
• Allfix is ​​a universal composition, suitable for all types of bases, provides a high level of adhesion.
• The facade is a one-component composition, frost-resistant and waterproof, suitable for outdoor work.
• Luxe-88 is a three-component adhesive, antibacterial and absolutely safe, provides instant adhesion.
• T-Avangard-K - not only glues, but also provides additional waterproofing.

How to put isolon under an electric heated floor

The first thing you will need to do is lay out the base for laying the thermal insulation. The subfloor can be poured in the form of a screed or assembled from a moisture-resistant plasterboard sheet. In any case, the surface should be as smooth and flat as possible.

Installation of isolon is carried out in the following order:

• We treat the base with a primer;
• We lay Izolon 100 without foil on the floor, carefully glue the joints, the edges should be laid on the walls with an allowance of 30 mm;
• The next layer is made of foil Isolon 500, it is best to lay two layers 10 mm thick with seams spaced apart;
• The sheets are laid out on the floor with the foil facing up and also taped with metallized tape;
• Depending on the design of the heated floor, it will be necessary to install fastenings for heating pipes or cables on the insulation surface. In this case, the floor is covered with screed under the tiles.

For wooden floors, before laying the heating elements, support bars are laid, and only after that the cable or plastic pipes for the coolant are installed. All that remains is to connect the heating, check and cover the floor with a tongue and groove board.

Recommendations and common mistakes

The first mistake appears due to the desire to save. Insulation based on Izolon is quite expensive, so even pieces and small pieces are used. In practice, this means the appearance of a large number of cold bridges at the joints. Pasted tape provides only a mechanical connection; it will not protect against heat loss. Therefore, insulation must be laid with a minimum number of panels.

The second mistake is related to the refusal to use vapor barrier and waterproofing. Membranes must be used without fail; Izolon is capable of absorbing moisture up to 0.01%. This is not much, but it is enough to lead to a sharp increase in the thermal conductivity of the material upon contact with water.

Flaws

• Izolon has a relatively high cost, so for large volumes of work this can become a problem;
• Despite its flexibility, the aluminum layer is very fragile and can be damaged by external influences during storage, transportation or installation. If there is damage, a cold bridge is formed, which, with a relatively small thickness of the material, becomes very noticeable;
• Not every finish is suitable for isolon. The material can be covered with a protective film or painted, but cannot be used as a basis for wallpapering and plastering. The classic application scheme involves fastening the material for subsequent finishing with suspended structures, such as drywall or the same lining.