How to pack a vapor barrier

During construction, it is extremely important to provide a high-quality vapor barrier, which would protect the load-carrying structures from excessive moisture. Otherwise very soon a fungus or mold spots will appear inside the walls, floor or ceiling, which eventually lead to the destruction of the building. But before this tenants will have to experience the negative changes in the microclimate inside the premises, which can cause chronic malaise and various illnesses. We will explain in detail how to choose and lay the vapor barrier in this article.

Types of vapor barriers

Modern building materials market offers a wide range of vapor barriers, which have extended the operatingthe time frame of the building and maintained a favorable microclimate inside.

The process of installation itself is quite simple and can be carried out even without the possession of professional skills. But before you start work, you need to choose the right vapor barrier, applicable specifically for your case.

Three types of vapor barrier materials are known, depending on the type of installation:

• ;
• painting;
• the troweling.

Below we will discuss each of them in more detail.

Awning vapor barrier

The overlying vapor barrier is provided with a special protective film.

Advantages of this type of vapor barrier are obvious:

• simple and quick installation;
• sealed connection segments;
• small number of seams;
• durability;
• good vapor barrier properties.

There are several types of pasting vapor barrier, depending on the materials used:

1. Polyethylene film - it can be of different density and length, sold in rolls. The film cuts are attached to each other using a regular or aluminum tape, and to the base with nails or staples( a construction stapler).Laying the film can be any side, leaving small gaps at the bottom and top for air circulation and providing a good stretch. If you do not leave the gaps, it is possible that condensation will form.
   
2. Penofol is a vapor barrier coating with a reflective layer. This is a special durable and flexible foamed polyethylene with one foil side. It is actively used in the construction of frame houses from the galvanized profile. Also great for building saunas and baths. Laying penofol quite simply, but the installation rules will depend on the characteristics of the structure. The material has not only excellent vapor barrier properties, but is also considered a good heat insulator, reflecting ultraviolet radiation and maintaining a comfortable temperature inside the house. Penofol for the floor is used mainly for hot or very humid rooms - baths, showers, kitchens, bathrooms.
   
3. Polypropylene film is a material that is more durable than polyethylene film. The best species are those with an anticondensate coating, which have a low vapor permeability. They do not allow the condensate to get on the inside and securely protect the structure. In other cases condensation forms on the inner surface of such films, so if you decide to use this material, make sure that it has a corresponding vapor barrier. One side of such a film has a rough surface. Lay the vapor barrier in a rough side outward so that condensation can evaporate quickly. But there are cases when the polypropylene film is spread in two layers: smooth or rough sides inside.
   

Paint vapor barrier

Painting vapor barrier is carried out by means of bituminous mastics( cold, asphalt, etc.), chlorinated rubber paints, polyvinylchloride varnishes. This type is suitable for protecting uninsulated roofs, as well as roofs, built of steel corrugated board.

To ensure the paint vapor barrier, you must first thoroughly clean the surface of any contaminants, dry it well and remove any irregularities with a special grout. Then apply the mastic evenly, having processed every centimeter of the area.

The paint vapor barrier is not only suitable for horizontal surfaces. To treat walls, chimneys or ventilation outlets, it is necessary to use heated mastic.

Depending on the type, the mastic should be heated to different degrees:

• bituminous - 180С;
• rubber-bituminous - 200С;
• tar - 160С;
• sounding - 70C.

Trowelling vapor barrier

The trowelling vapor barrier is a coating of surfaces with a cement-sand mortar made of cement grade 50. Sealing joints is carried out with special solutions, for example, UT-31.

After grouting mortar, the walls are painted with paint or covered with cement. This type of vapor barrier is mainly used for walls.

Which side to lay

Many inexperienced builders often do poor work, because they do not know which side to lay the vapor barrier. As a result, there is no use in such work, and money is wasted.

Basic rules for installing insulation:

1. If you use a double-sided film, where one side is smooth and the other side is rough, always lay the material with a smooth surface inside, that is, a heater. The rough side should contact with moisture and allow it to evaporate without hindrance. If done on the contrary, the glossy layer will not take steam, but accumulate it in the form of condensate. Its task is to protect the thermal insulation material, not missing the accumulated steam roughened side.
2. If you are working with a polypropylene film with a single-sided glossy( laminated) layer, it is necessary to lay the vapor barrier in the smooth side inwards, and the wicker - outward.
3. When working with foil films, remember that the foil layer is designed to reflect ultraviolet radiation. Obeying the logic, it can be concluded that it is necessary to lay such a vapor barrier with foil outwards.

The above principles apply to almost all cases, however manufacturers of modern vapor barrier materials can still make their own adjustments, so always read the instructions on the packaging. A striking example is the vapor barrier film Izospan, the manufacturer of which recommends that it be placed with its rough side inward, and the glossy film outward.

Installing a vapor barrier

Knowing how to put a vapor barrier properly will avoid the formation of mold and fungus. Depending on which part of the house you work with, the installation of materials will be different. Consider the most popular options for laying the vapor barrier in a residential area.

Steam insulation of the roof

For a competent vapor barrier of the roof, you need to know some of the nuances. So, rolls of material should be rolled from top to bottom, slightly pushing each next layer to the previous overlap by 3-5 cm.

A special tape is used to connect the individual parts of the coating, ensuring tightness of the seam. Most often, a strong aluminum tape or a rubberized adhesive tape is used.

If it is a vapor barrier of an insulated roof, the film should be placed in a horizontal position and secured to the crate or flooring.

Steam insulation of the ceiling

To prepare the ceiling for the installation of vapor barrier, a lot of time will not be required. You only need to sweep the surface, collect the dust with a damp cloth and let it dry completely. Then it is necessary to cover and wipe all irregularities and notches, if any, to level the ceiling with a primer and wait until it dries.

The vapor barrier film needs to be stretched so that there are no irregularities in which condensation can accumulate. To ensure such a stretch on the ceiling, attach the material to the ceiling beams with ordinary transparent tape. The cuts of the film must also be overlapped and the joint sealed with adhesive tape. At the junction line, after every 30 cm, nail with wide hats.

Ceiling vapor barrier is attached separately or simultaneously with a heater using wooden or metal rails. Reiki should be screwed with the same frequency that nails were driven - 30 cm. Very useful in this work will be a furniture stapler - the staples will replace nails with large hats and provide a reliable fixation.

In the construction shop you can be offered a sheet vapor barrier for the ceiling. To attach it, you will also need a special profile, which you can buy or make with your own hands. In this situation, you first need to attach the frame to the ceiling, and then insert a sheet vapor barrier and a heater into it. The sheets are also lapped onto the walls to prevent cracks in the areas where the walls meet the ceiling beams.

In some cases, if the ceiling is suitable, a varnish vapor barrier can be used. The material is applied in several layers, each of which must be thoroughly dried before applying the next one. Usually 2-3 layers of vapor barrier are sufficient.

Steam insulation of the wall

The steam insulation must be laid on the walls by rolling rolls from the bottom up and fixing the horizontal parts of the material with wooden slats or a galvanized profile. It is necessary to leave a vent for air circulation. It is usually made between the vapor barrier and the interior trim at a distance of about 4 cm. This condition must be observed in all rooms, especially where the heating is unstable, often high humidity.

The lower part of the vapor barrier material should be located below the base level of the house, so that water can not penetrate into the walls.

Steam insulation of the floor

Before laying the vapor barrier on the floor, all the wooden elements of the base must be carefully treated: bars, logs and boards. Treatment is carried out by antiseptic means, which protect the tree from decay and spoilage by parasites.

If you intend to install a vapor barrier on an already constructed floor, you should disassemble it by removing the finishing floor and removing the old vapor and thermal insulation materials that have become unusable. After this, you should thoroughly clean everything and, just in case, process the wooden segments of the rough floor with an antiseptic. After this, a new heat and vapor barrier is laid.

For more information on how to lay the vapor barrier on the floor and walls, see the video below:

We hope this article will help you properly fix the vapor barrier and cope with any of its types. In any case, do not forget to read the instruction from the manufacturer on the packaging in order to avoid rare, but possible exceptions to the method of installation.