Izospan: types, specifications, instructions for use

In many building structures, vapor barrier, wind protection, and waterproofing are used. One of the proven manufacturers of these products is an enterprise from Tver, which produces vapor-waterproofing materials and windproof membranes under the Izospan brand. The article describes the scope, technical characteristics and instructions for use of various types of Izospan.

Types of Isospan (Isospan)

Let’s start with what Isospan is. This is a trademark under which the Tver enterprise Geks produces non-woven building materials – films and membranes for various purposes. In short, there are vapor barrier, windproof and waterproof roll materials. There are a lot of materials, so the names, applications and features are summarized in a table. It’s easier to navigate that way.

As you can see, all Izospan materials can be divided into three groups:

• Wind protection. This is a group of materials Izospan A and varieties. These are materials that protect the insulation from blowing, keeping warm. At the same time, they remain permeable to steam, but do not conduct / do not pass moisture.
• Steam and waterproofing materials. These are Izospan B, C, R and several of their varieties. They do not let moisture through in any form.
• Energy-saving vapor-waterproofing Izospan F. It is distinguished by the presence of a metallized layer, it does not let moisture through in any form – neither steam nor liquid.

There are also connecting materials – one- and two-sided connecting tapes on a different basis. They are needed during installation, they allow at the joints to avoid deterioration in performance. Some allow you to achieve tight connections.

How to distinguish by name

In the name of the materials, a key letter is affixed, by which it is possible to determine the group and basic properties. So Izospan A with all other indices denotes a vapor-permeable membrane. Izospan B, D, C – hydro-vapor barrier. The difference between the films of this group and the first is that these materials (B, C, D) do not let vapor through. The materials of the first group (A) conduct it (steam), and retain only water. The exception is Izospan A base. It does not retain water and conducts steam.

The third group is also hydro-vapor barrier. It differs in that it has a metallized coating. The names of materials in this group contain the letter F: FD, FX, FS, FB, RF. They are used to more effectively retain heat, as heat rays are reflected from the shiny coating. But reflection is possible only if there is an air gap in front of the film of 3,5 cm (or more).

After the first letter in the Izospan marking, there is often a second one. It describes the special properties of the material. It can also be an abbreviation or a short word. For example, the presence of the letter M or S indicates the presence of reinforcement. The prefix fix means that there are strips of glue along the edges, so there is no need to use adhesive tape.

Izospan A: instructions for use

Izospan A group of materials – vapor-conducting windproof membranes that do not conduct water in a liquid state. The exception is Izospan A base. This membrane is only a windscreen. It does not interfere with the passage of steam and water. It is used in the ceiling above the ventilated facade, stuffed from the side of the subfloor. Protects from blowing through mineral wool, does not prevent the removal of moisture from the insulation.

To understand where and how best to use Isospan A, look at the characteristics. Once again: the film is not blown (keeps heat), removes steam, does not let water through. These properties are needed in the following constructions.

Rules for laying and installing windproof vapor-permeable membranes

Vapor barrier materials are laid on vertical, inclined and horizontal surfaces. Despite the fact that the designs are different, the installation rules do not differ. Here’s what to remember:

1. On pitched roofs and walls, work begins from the bottom. On horizontal roofs – from one of the walls.
2. The second layer of material is laid with an overlap. That is, one panel overlaps another by at least:
   • 10 cm on the walls;
   • 15 cm on roofs;
   • 15-20 cm in ceilings.
3. Vertical joints (if any) have the same dimensions.
4. All joints of the canvases are glued with double-sided adhesive tapes.
5. The adjunction to the walls, the truss system is also glued. To adjoin the rafter system, it is recommended to use the Izospan self-adhesive sealing tape. For joints – KL, for adjoining the structure KL +.

The task of vapor-permeable waterproofing and wind protection is to let steam through, but prevent moisture from entering in a liquid state. Therefore, the strength of the joints is important.

On a pitched roof, over insulation

Vapor barrier is laid on top of mineral wool, covered with any roofing material on top. Let’s see how everything works. Here it is necessary that the steam that got into the insulation from the attic be removed. At the same time, condensate and possible leaks did not get into the insulation. So you need to remove the steam and not let the water through. What does Izospan A.

The membranes are unfolded with the logo “towards you”. It is better to lay it not in tension, but with sagging. In this case, condensate, from which there is no escape on the roof, will drain to the center, and then to the gutter of the drainage system. So it will dry out faster even in damp times, moisture will be less retained, less likely to get into the insulation.

On top of the vapor barrier, slats are stuffed along the rafters, and then across the crate for the installation of roofing material. With such a device and the presence of ventilation holes in the roof, the vapor barrier will be blown and dry.

In the frame walls from the side of the street

The humidity is usually higher indoors than outdoors. And no matter how we protect the walls, steam seeps through them. These are the laws of physics. And since he hit the wall, he must be taken out. So here the same task is to remove steam. This can only be done from the side of the street. So Izospan A in the frame walls is also laid from the side of the street. Here you can use all types of Isospan A, except for the “base”.

When using Izospan A “in its pure form”, it does not matter which side to lay it on. All other modifications – AS, AQ, AM – are deployed so that the logo is outward.

When insulating walls with mineral wool and for ventilated facades

With external wall insulation, in ventilated facades, the situation is almost the same as with the frame. Some moisture seeps into the wall from the room. Then it penetrates into the heater. Since wet mineral wool is a poor insulation, care must be taken to ensure that this steam is quickly removed. At the same time, it is necessary to protect the cotton wool from getting wet and to keep warm to the maximum. That is, the same vapor-permeable membranes of the Izospan A group solve the problem.

Any vapor barrier for use in case of external wall insulation, except for Isospan A with OZD, AF + and basement. The laying rule is the same – turn the logo towards you. For use in the system of ventilated facades, Izospan AF + is recommended for use. If a metal structure is used, its strength will be a guarantee that the vapor barrier will not tear. If the ventilated facade is sheathing on wooden bars, Izospan AM, AS and AQ may well be suitable in any of the options.

Ceiling over ventilated subfloor

The ceiling insulated with mineral wool over the ventilated plinth has its own characteristics. First and foremost, for the circuit to work, the subfloor must be ventilated. This means that there must be air in the foundation. And they must be open even in winter, otherwise you will have wet insulation and cold in the house.

How does this pie work? From the side of the house, moisture and steam seep into the insulation. If you simply knock out the insulation with a mesh or slats, the wind walking underground will do an excellent job of removing moisture. But at the same time, it will carry away heat and gradually take out particles of mineral wool, reducing its thickness. Here, in order to get rid of blowing heat and insulation, they use the Izospan A basement vapor barrier. It passes freely steam and moisture in both directions, but does not pass wind.

Such an objection may arise. Moisture from the soil will evaporate and enter the insulation. Under certain conditions, it condenses on the membrane, causing the insulation to get wet. Maybe it’s better to use a vapor barrier with waterproofing properties? No. It won’t work. If the membrane does not conduct moisture, then the one that condenses or gets into the insulation will remain there. Because it will not heat up enough to evaporate and come out in the form of steam. In a couple of years you will have bags of water hanging from the ceiling and completely wet and unusable insulation.

And in order to reduce the evaporation of moisture from the soil, a dense film is placed in the underground, a layer of sand (any, but without clay and dust) is poured on it with a layer of 5-10 cm. The film retains most of the moisture, and the sand works as an adsorbent, absorbing the fallen condensate. It (sand) is also dried by the walking wind.

Interfloor and attic flooring

In overlappings, steam enters from below, and must be removed from above. Therefore, a vapor barrier to protect against moisture is placed from below, and a vapor-permeable wind protection is placed from above. In this cake, it additionally protects against the penetration of mineral wool particles into the room. Putting Izospan should be all the same – the logo should be facing you.

In the interfloor overlap, to reduce the cost, vapor-permeable Isospan can be replaced with non-woven material (any type of geotextile). Its main function here is to protect against the penetration of small particles of mineral wool into the air. But you can do this only if the flooring is sheet material in two layers, moreover, in a space between the seams. Otherwise, moisture can seep in and then just a non-woven material will not protect the insulation from getting wet.

In the attic floor, such a replacement is not considered at all – here it is also necessary to protect heat from weathering. So wind protection is essential here.

Also note that the vapor barrier is attached to the beams with counter rails. And the flooring is already laid on them. Counter rails are needed to create a ventilation gap, which is a prerequisite for the evaporation of moisture. It is important.

Instructions for use of vapor barrier Izospan B, C, D

Izospan vapor barrier films are at the same time waterproofing. They do not let water or steam through. What is the difference between Isospan A and B? The fact that B does not let steam through, A does. This is in short.

Made from different materials. There are films, nonwovens and fabrics made of polyethylene and polypropylene. Fabric-based materials have very high strength characteristics. Their use is justified in places where they can be subjected to high mechanical stress. Technical characteristics of Izospan vapor barrier films are given in the table.

The main task of these materials is to cut off steam from the insulation as efficiently as possible and at the same time provide protection from moisture. A “side”, but important effect is protection against the penetration of mineral wool particles into the indoor air. It is applied in a design of walls, overlappings, on a roof, at the device of a concrete floor. Vapor barrier is often part of the “pies” above, simply because they perform other tasks.

Vapor barrier installation rules

The main task when laying vapor barrier films is to achieve as complete tightness as possible. It is necessary to pass as little steam as possible into the heater. We make all connections reliable using sealing and connecting tapes. The basic rules for vapor barrier do not differ from those described above:

• On walls and roofs, start from the bottom.
• The next canvas overlaps the first one by 10-20 cm.
• We make vertical joints with an overlap of at least 20 cm.
  

• We glue all connections with double-sided tape.
• We make the connection to building materials with the help of mounting and connecting tapes.
• When used for flat roofs and ceilings, the vapor barrier is placed on the walls and sealed there.

In addition to gluing the joints of the canvases, it is also important to use even planks-bars for the final fixing of the material. They tightly press the material, sealing at the same time the holes that the fasteners invariably break through.

Pitched roofs – insulated and non-insulated

Pitched roofs can be insulated or cold. In any case, a vapor barrier is laid from the attic side. It does not let steam into the insulation and this is its main task for this case. But Izospan for insulated roofs and non-insulated roofs is recommended differently:

• for insulated roofs, it is better to use RS, B or B fix, they differ in strength (RS is stronger);
• for non-insulated – D or D fix, DM (DM is stronger than just D).

Films Izospan RS and B have one rough side, the other is smooth. So, Izospan B and RS must be turned with the rough side into the room. We unfold the smooth one to the insulation or roofing material.

Flat insulated roofs

When insulating a flat roof, the vapor barrier is laid on the ceiling under the insulation. The purpose of this layer is twofold. On the one hand, do not let steam into the insulation, on the other hand, cut off moisture from the ceiling in case of leakage.

In this case, it is recommended to use Izospan D and RM, RS. They have sufficient strength to withstand the loads that will necessarily arise when laying insulation.

Izospan B: instructions for use for walls

In the pie of frame walls, the Isospan V vapor barrier is laid from the side of the room. The task of vapor barrier: let steam into the insulation as little as possible. What gets into it (and it will definitely get into it) will come out, since there is a vapor-permeable film Izospan A outside. But the less moisture there is, the better.

In this case, Izospan RS (RS) and B are recommended for use. RS strength is required only if you plan a break in work and the wall cladding will be mounted after some time. The smooth side of Izospan B goes to the heater, the rough side is directed into the room. This is the basic rule.

Please note that in the diagram, Izospan B is nailed to the racks with planks, and wall sheathing sheet material is mounted on the lathing planks. This option is good, as it allows you to isolate the holes that the fastener makes with the help of a strip. There is another option – you can attach the film to the racks using a stapler and staples with wide backs. The inconvenience is that the rack will not be visible and it is not clear where to attach the sheet material. But the option is possible, although not ideal.

Attic and interfloor ceilings

Vapor barrier in a wooden floor pie is needed from the side of the lower room. Looking from the bottom up, the sequence goes like this:

• ceiling lining;
• vapor barrier (Izospan V);
• draft ceiling;
• insulation between beams;
• vapor-permeable film (Izospan A);
• floor laid on counter rail.

How does the vapor barrier work in this cake? It does not let vaporous moisture from the room into the insulation. In the event of a leak from above, it will also retain moisture, but this is an emergency and the water will not hold for a long time.

Which side to lay Izospan B in this case? Rough side in, smooth side up. When installing, try to damage the panel as little as possible. If a hole has formed somewhere, we seal it with tape. Better branded, but you can just good, with a high-quality sticky layer.

Base plinth

The basement ceiling is built according to a completely different logic. Here the steam will flow from top to bottom. From a warm room with moist air to a cooler and drier underground. And so that moisture penetrates into the insulation as little as possible, we put a vapor barrier on it (thermal insulation). The steam that got into the insulation will either fall on the ground in the form of drops, or be carried away by the wind in a vapor state.

Izospan B and RS are recommended for use. When laying, we turn the rough side to the insulation, the smooth side looks into the room. The films are laid on beams, fastened with planks – counter-rails. The flooring is already laid on them.

For better heat conservation, you can use vapor barrier materials with a metallized layer: RF, FS, FD, FX. In this case, the thickness of the counter rails is at least 35 mm. This is the minimum gap that ensures effective heat reflection.

Screed on a concrete base

If you need to level a concrete slab, use a screed more often. To prevent water from the solution from leaving the ceiling, it is advisable to use waterproofing. It can be a coating or roll material. The cheapest is film. But you have to walk on it and it is unlikely that it will remain intact. Especially if the screed is reinforced. Is it possible to pour a screed without a film? If you are not afraid to flood the neighbors from below, then you can. Or if you use coating waterproofing. Without it, most likely, the screed will not have the required strength. A certain amount of moisture is required for the formation of cement stone. And it will go partially into the slab, partially seep through the cracks. What will be the result is unknown. Accordingly, the film is desirable to use.

Under the screed on a concrete base, it is recommended to lay the vapor barrier Isospan D (D) or Isospan RM (RM). These are high strength waterproofing materials. Which side to lay these materials does not matter. But Izospan D has a very high strength and it makes sense to use it only if reinforcement is to be laid. Under the screed without reinforcement, RM is enough.

If there are significant depressions at the base, it is better to repair them; it makes sense to cut off too protruding humps. This will not only increase the chances of the safety of the film, but also allow you to make a thinner screed. And this is a significant savings.

Vapor barrier with reflective layer Izospan F

The third group of materials is vapor barrier films with the effect of heat reflection. They differ in that the outer layer is a metallized film (lavsan or polypropylene). They can be used instead of similar materials (vapor barrier) in all the above designs. In the presence of an air gap, the material is able to reflect heat radiation back into the room.

Energy-efficient vapor barrier Izospan F is installed from the side of the room. When installing, turn the shiny side into the room. The use of this group of materials can reduce heating costs by about 10%, but there is still debate about this: not everyone believes in it.

The second scope of Izospan F is a substrate for finishing floor coverings. Under the laminate, parquet board, film floor heating, it is recommended to use Izospan FX. This is polyethylene foam with a thickness of 2-5 mm with a glued metallized film. In addition to reflecting heat, it is also thermal insulation. Under all other coatings, you can put any other material of this group.

Use of Izospan F in the underfloor heating system

When laying a warm floor system in the screed, the cake remains the same. Only pipe or cable is added. But they need to be laid according to a certain pattern, so a metal mesh is also needed. Pipes of a water-heated floor or an electric heating cable are tied to it.

In order not to heat the ceiling to the neighbors from below, it is advisable to direct the heat as high as possible. To solve this problem, a heater is laid on the slab, and waterproofing with a heat-reflecting effect is placed on it. In this case, the material does not let water into the stove, and reduces heat loss during operation. For underfloor heating, it is recommended to use Izospan RF, FX, FD, FS.