Izospan A, B, C, D: insulation specifications and rules of use

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Lydia Korzheva
Last update: May 2019

The device of moisture and vapor barrier is a very important stage of construction. One of the best materials used for this purpose is isospan. It belongs to the category of relatively new products used in the protection of structures. The manufacturer presents a wide range of insulation films that differ in purpose.

You will learn all about the assortment of membrane films labeled as Isospan A, B, C, D from our article. We have described in detail popular insulation materials, given their technical characteristics. Independent home masters with us will find installation manuals and useful tips.

Overview of existing varieties of isospan

For the most part, isospan is released in the form of a membrane or film. Both versions have a vapor barrier function. There are types that are 100% waterproof and unilaterally leaky. If we separately consider the types of this material, then each is intended for separate tasks.

The term isospan hides four broad groups - A, B, C, D. They are distinguished by individual design features.

Apply isospan to the device attic insulation systemsinstallation of cold roofs, arrangement of floorsbath construction increase wall heating as an insulator for building envelopes. The material is especially effective as a protection for insulation systems and wooden elements from putrefactive processes, and metal ones against corrosion.

There is isospan used inside buildings, and its other varieties are intended for outdoor use. There is also an isospan of universal use. In any case, its use makes it possible to significantly prolong the operating time of the insulation, which, under the influence of moisture, quickly loses its properties.

The main groups of isospan
Three main groups of isospan can be distinguished: moisture- and windproof, steam- and moisture-proof, vapor-proof. The materials included in the second group are used for interior decoration

Steamproof isospan is used when performing both internal and external works. The functionality of the material is divided into classes.

Group A Insulation Material

Material marked with the letter “A” belongs to the first group. It is characterized by high density, therefore it is indispensable for warming attics, walls, roofs. It does not develop fungi, mold.

This diffusion membrane retains water, but steam passes through it unhindered. For the manufacture of polypropylene. It strengthens and protects the thermal insulation from the influence of atmospheric outdoor moisture or cold air from the side of the room, which is not heated.

Izospan A, like a wind barrier
Izospan A is an excellent wind barrier for ventilated facades. It mitigates the consequences caused by the onset of side winds favoring the escape of heated air from the insulating layer.

In order for Isospan A to fully reveal its capabilities, it is necessary to strictly follow the technology during installation. Since air jets pass through it only unilaterally, in no case should the sides be confused. Otherwise, the insulation layer will get wet due to the accumulation of moisture in it.

Isospan A is produced in rolls 1.6 m wide. The area of ​​the material in the reel is 35.7 m². The optimum temperature limits for operation are -60 - 80⁰. For three or even four months, the membrane without loss of characteristics can be influenced by ultraviolet radiation. In the future, these aggressive rays will gradually reduce the UV stability of the material.

Isospan marked with letter A may contain fire retardant additives. Then, to all its characteristics, one more is added - protection against fire. This brand belongs to the G1 flammability group, and according to the flame propagation speed - to the RP1 group.

The material withstands quite high breaking forces - from 125 longitudinal and from 95 N / 5 cm transverse. This is facilitated by special additives that enhance the structure of the material.

The vapor permeability of the material is a minimum of 3500 g / m² day. Water resistance parameter - 330 - mm. water Art. Based on these characteristics, isospan A is advisable to use when installing ventilated facades, frame walling, a roof with a double crate and slopes at an angle of 35 °.

Isospan AS
The 3-layer AS membrane insulates both wall and roof structures from street moisture and steam. The presence of such a barrier guarantees the safety of the insulation

In contrast to the group A membrane, the AM film has a two-layer structure. She also found application for the protection of insulation, roofing elements from condensation, weathering.

These types of insulation have a number of differences:

  1. As - the strongest, in addition, it stands out by a rather significant period of operation, but the rate of steam pass is only 1000 g / m² per day.
  2. AND - The best view of steam throughput.
  3. AD - strong membrane with vapor permeability of 1500 g / m² per day.

There are differences in terms of installation. If brand A is selected, an air gap is needed, otherwise the steam will be vented inefficiently. Membranes AS, AD are mounted directly on the insulation.

The second group marked B

This vapor barrier has a slightly lower price.

The technical parameters of Isospan B are as follows:

  • composition - polypropylene;
  • minimum breaking load - 130 N / 5 cm;
  • minimum lateral load - 107N / 5 cm;
  • application temperature - -60 - 80⁰;
  • water resistance - 1000 mm of water. With t. Minimum;
  • UV resistance - 3 - 4 months;
  • minimum vapor permeability - 7 gr. on m² per day;
  • The structure is two-layer.

It is used as a subroofing film in frame building envelopes, in interior partitions.On the one hand, it is smooth, the opposite side is rough, just moisture is retained on it and its evaporation occurs.

With its help, the structure is insured against penetration insulation layer of the ceilingwalls system floor insulation in a private house.

Isospan B
Lay the grade B isospan so that the rough side is on top. It is a high-quality vapor and waterproofing for rooms with traditionally high humidity - bathrooms, bathrooms, showers, basements

The price of this brand is the most affordable. Unlike brand A, this material is not fixed on top of the insulation, but on its lower side. Do it from bottom to top, then lap. For better capture of water vapor, a 5-centimeter clearance above the rough layer is required.

Features of the material of group C

Regarding resistance to vapor permeation, water resistance, UV stability, this type of insulation does not differ from the previous material. Grade C isospan has the same temperature range: (-60) - (80⁰). The difference is in the breaking load, here it is larger - the longitudinal minimum is 197, the transverse - 119 N / 5 cm.

The two-layer film is especially durable. Group C polymer membranes perform hydro and vapor barrier protection attic insulation, attics, roof slopes with a maximum of 35⁰.

They are used as a waterproofing substrate for a metal tile, since it perfectly protects the rafter system from rain and melt water. In addition, it is a good waterproofing for bases of different types. Apply the material in the case of concrete floors in places of high humidity.

Brand D Product Description

A distinctive feature of isospan D is its good resistance to UV rays. Tensile strength is also high - longitudinal tensile load - not less than 1068 N / 5 cm, 890 - transverse.

Isospan D Parameters
This vapor barrier enters the market in rolls measuring 160 x 437.5 cm, which is 70 m². The reel weighs 7.7 kg. Elongation Ratio - Within 23%

Due to its high strength, brand D polypropylene fabric can easily withstand considerable mechanical forces during installation and operation, including the weight of snow. For this reason, it is quite suitable as an unstable roof that has been functioning normally for about 4 months.

The material proved itself well in the role of under-roof waterproofing in cold roofs. It saves wooden elements from the destructive effects of moisture penetrating from the outside, as well as wind, snow, which can be there through leaks in the roof. This is an effective waterproofing layer in floor heating systemsbasement ceilings.

Isospan Installation Instructions

Steam, moisture and wind protection of the building - a comprehensive event. Using glassine or plastic film is ineffective. Izospan is specially designed for this purpose and its high qualities are tested by practice.

For installation, in addition to the actual isospan, a supply of tools and fasteners is required:

  • special scissors;
  • self-tapping screws;
  • construction stapler;
  • connecting tape;
  • metal profiles or wooden slats.

It should be remembered that on the walls the membrane is attached both from the inside of the room, and from the outside, and on the roof - only from the inside. Features of a particular type of isospan are reflected in the instructions for use of the material.

Installation of a group A membrane

The best application of this heat-insulating, waterproofing, windproof membrane is to protect the frame wall of low-rise buildings from moisture and wind. Mount it on the outside of the insulation layer under the exterior decoration of the building.

Izospan A for frame walls
The outer side of isospan A does not allow moisture and wind to affect the state of the insulation. Internal - prevents condensation, as has the ability to remove steam

Laying isospan A in accordance with its technical characteristics is carried out on top of the insulation in a special frame.

The technology is simple and does not require special qualifications:

  1. The roll is expanded and cut into panels of the required size.
  2. The segments of the membrane are arranged alternately on the frame horizontally overlapping outward, starting from the bottom, and moving up.
  3. Fix the protection on the frame with an overlap using a construction stapler or another method. The minimum overlap value both horizontally and vertically is 100 mm.
  4. The material is further strengthened. To do this, stretched panels are pinned to the rafters with a construction stapler.
  5. To seal the overlap, the joints of the panels are fastened with a 2-sided KL isospan tape.
  6. In the area of ​​fastening lay a self-adhesive tape.
  7. On top of the isospan layer, wooden counter-rails are mounted vertically with respect to the frame. They are pre-treated with an antiseptic. The size of the rails is 40 x 50 mm. They serve as the supporting structure for the outer skin - in the form of lining, siding, etc.

A prerequisite is a ventilation gap equal to the thickness of the counter-strip between the isospan layer and the outer skin. The bottom edge of the membrane is located so as to divert the flowing moisture into the drain of the base of the building.

Laying a film of Am and As in an insulated pitched roof

For this type of roof, experts recommend choosing isospan Am or As.

Isospan Am or As
The material protects the supporting structure and insulation from condensation collected under the roof, as well as from snow, wind, moisture, which fall through the loose laying of the coating

They lay the membrane without a ventilation gap, so there is no need to arrange an additional crate between the insulation layer and isospan. Fix it in a stretched form.

The sequence of operations is as follows:

  1. Roll the roll and cut directly on top of the insulation.
  2. Lay out the panels horizontally, turning the white side to the insulation. The beginning of installation is the lower part of the roof. The segments overlap horizontally and vertically by at least 15 cm.
  3. Strengthen the membrane along the rafters with a stapler.
  4. The joints are fastened with a solid 2-sided adhesive tape isospan KL.
  5. Traces of fastening with nails or self-tapping screws are closed - glued with a self-adhesive strip along the rafters and other elements. This is especially true for roofs with a slight slope - up to 22⁰.
  6. Wooden antiseptic slats 4 x 5 cm are vertically fastened over the tape along the rafters.
  7. Mount the crate on the counter rails. Based on the type of roof, this can be a continuous flooring.

To eliminate the under-roof condensate between the front side of the film and the roof covering, a condensation gap is arranged using rails with a thickness of about 50 mm.

For the free movement of air in the space under the roof, the bottom of the roof and the area of ​​the ridge are supplemented with ventilation holes. Moisture from the membrane surface drains into the drain along the lower edge of the membrane

When installing isospan on the crate, slight sagging is allowed. A membrane without insulation is practically useless.

The use of insulation material B

This type of membrane perfectly performs the function of vapor barrier, protecting the insulation layer from water vapor rushing upward from the side of the room, and also protects the space of the rooms from getting insulating particles in them.

Mount it from the side of the heater, directed inside the room. Installation is carried out using a building stapler on rafters or rough sheathing. Sometimes galvanized nails are used for this purpose. Correctly, when the flat side is closely adjacent to the insulation.

Work starts from the bottom. Vertical and horizontal overlap are the same as when installing other types of isospan - from 150 to 200 mm.

As in the case of Isospan Am, the joints are glued with the Isospan KL, SL. The material contact points with constructions of any material are sealed by using the ML proff single-sided adhesive strip.

Lining vapor barrier
If the room is finished with lining, the vapor barrier is fixed with wooden strips soaked with septic tank 4 x 5 cm. For plating with plasterboard sheets - galvanized profiles

The interior finish is attached to the wooden base with a ventilation gap of about 40 mm. In the case of the use of isospan as a vapor barrier for the frame wall, it is fixed from the inside of the insulation to the loaded parts of the frame or to the rough skin.

As a tool, a stapler is used, although the use of galvanized nails is also possible. It is laid on the heater with an even side to it. When decorating gypsum plasterboard walls, galvanized profiles are used, with clapboard - wooden counterrails.

Izospan as a vapor barrier of the attic floor is placed in the gap of the ceiling finishing material - the draft ceiling. A smooth surface is turned to the latter. Mandatory in this case is the ventilation gap.

The vapor-permeable membrane of brand B is also a good hydro-vapor barrier for interfloor ceilings. Mounted between ceiling trim and draft system. The rough side is turned down. They fix on the beams with an overlap.

Between the insulation layer and the final layer of vapor barrier, between the finishing floor and the vapor barrier layer, between the finishing ceiling material and the lower layer of isospan B, a ventilation gap is arranged.

Basement waterproofing
The scheme of waterproofing the basement. Here 1 - floor, 2 - isospan B (vapor barrier), 3 - membrane D (as hydro-vapor barrier), 4 - heater layer, 5 - counterrail, 6 - beam, 7 - overlap

The bottom of the basement must be protected with a vapor barrier. This must be done so that moisture does not penetrate from the ground to the insulation and other structural elements. The recommended type of isospan for this purpose is D.

The best option for using brand D

The type of izospan D for cold pitched roofs is an excellent hydro-vapor barrier. Through its use, elements and structures of the attic space made of wood are protected from under-roof condensate, snow, wind, and atmospheric moisture.

Starting the installation of a protective barrier for a cold pitched roof, isospan D is laid out and cut. All this is done right on the roof rafters. The advantage of the material is that it does not matter which side to attach this isospan to, which is very convenient.

Horizontal sections are overlapped, traditionally starting from the bottom of the roof structure.

Conclusions and useful video on the topic

Video # 1. How to install a vapor barrier in a house:

Video # 2. The sequence of work when arranging floor and ceiling ceilings:

Video # 3. Demonstration of the process of laying the vapor barrier film B to protect the roofing cake from household steam:

Laying the hydro- and vapor barrier is an extremely simple process, but the protection they provide to the structures is very effective. Protection against atmospheric water and domestic fumes is a guarantee of a long service life of materials used in construction.

The key point when choosing a particular type of protection is the specific location and circumstances of its installation. In this regard, when purchasing material, you need to carefully study the acceptable options for its use.

Tell us about how Izospan brand insulation films were used in the arrangement of the attic in your own country house or in a country house. Share useful information on the topic of the article, which may be useful to site visitors. Please leave comments, post photos, ask questions in the block below.

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Visitors Comments
  1. Svetlana

    Good evening! There is no information on the warranty period of Izospan anywhere. It is widely believed that no testing of this material has been conducted and does not indicate any warranties by Hex.