How to properly lay a vapor barrier membrane or film inside the house: which side to glue, types of fastening and installation options

Maintaining appropriate insulation is essential when working on a home’s interior to keep it cozy and energy-efficient. A vital component of this procedure is the vapor barrier film or membrane. This substance keeps moisture from seeping into the walls, which could cause rot, mold, and other structural problems.

The effectiveness of a vapor barrier depends on how well it is installed. Its performance can be affected by the side you decide to glue it to, the kinds of fasteners you use, and the installation technique. Whether you’re a professional or a do-it-yourself enthusiast, knowing these specifics will help you steer clear of common pitfalls and guarantee the safety of your house.

This article will discuss the various kinds of vapor barriers that are available, which side is best to face, and the best ways to secure them in place. You can maintain the long-lasting and dry walls in your house by taking the proper measures.

Vapor barrier of walls

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One of the first things to do when building and finishing a house is to create a vapor barrier for the walls. Moisture protection will keep the building from collapsing and provide warmth and comfort to the occupants. in addition to defense against fungus, which has a detrimental impact on everyone in the household’s health.

Different materials are used to create vapor barriers both inside and outside the building. Installation technology necessitates adherence to the phases of the job as well as the guidelines that determine the standard of the work produced.

Why is it necessary to install a vapor barrier inside and outside the house

Insulation materials that absorb moisture, such as breathable materials, are frequently used when finishing a house’s exterior and interior walls. A condensate collection point consequently emerges. As a result, the insulation is destroyed, fungus grows, and finishing materials are distorted and damaged (wallpaper peeling, tiles falling off, deformation of plasterboard sheets).

A vapor barrier that can prevent moisture from getting to the insulation is used to create the required microclimate in the space. Many of these materials are also breathable, which is essential for finishing materials and walls alike. You can create ventilation with this feature, which is essential for all wall-mounted elements.

Situations where a vapor barrier is necessary:

1. When the walls inside the room are insulated with mineral wool. It is breathable, it is destroyed when moisture gets in.
2. Walls covered with plasterboard and other cladding. Mainly, condensation is created between the rough wall and the cladding, which negatively affects the finish.
3. A vapor barrier layer is installed outside to protect the walls from external moisture. This is done when insulating the facade of a building.

To prevent moisture damage to your walls when installing a vapor barrier membrane or film inside your home, it’s imperative to make sure the installation is done correctly. The secret is to understand the different installation options, choose the appropriate fastening method, and know which side of the membrane to face inward. By doing this correctly, you can extend the life of your home’s structure and maintain a comfortable indoor environment.

Types of vapor barrier material: which is better

There are a plethora of options for vapor barriers in the construction industry. It comes in rolls or as a liquid. Every material has a unique composition and purpose. Some are only used indoors, while others are used for walls outside the home.

Mastic

The base of mastic is bitumen-polymer. When applied to the surface, it forms a layer that both shields the rough base from moisture and lets it "breathe." Using a brush, mastic is applied in two layers to dry, clean walls composed of different materials (concrete, brick, and wood). The first layer is dried and then bitumen is applied. One benefit is that the mixture can be purchased already prepared, saving time and effort when cutting or cooking. Mastic has a service life of over 25 years.

Membranes

On the construction market, a wide range of membrane materials are available. The following characteristics belong to them:

• installation on the outside of the insulation. The membrane protects the outer wall from precipitation, winds. Siding, clapboard are installed on top;

The membrane needs to be securely fastened and fit snugly against the insulation. because high winds have the potential to tear it.

• For vapor barrier for walls inside the house, use "Megaizol B" – a polypropylene film in 2 layers with an "anti-condensate" surface. The film protects the walls from the appearance of a dew point, which leads to the development of fungus, dampness;
• Izospan FD, FS, FX – reflective surfaces used in bathrooms, baths, saunas.

Given the variety of membrane options available, it’s important to consider whether they are meant for outdoor use, indoor vapor barriers, or bathtubs.

Vapor barrier film

Use a film with a thickness of less than 0.1 mm for the vapor barrier. Of all the listed, it is the most commonly used. It is impermeable and prevents air from passing through. They have, nevertheless, started manufacturing air-permeable film lately.

Vapor barrier film is useful because it addresses these issues:

1. Microventilation of walls and insulation occurs.
2. Partial removal of condensate collected when the temperature outside changes.
3. In saunas and baths, where there is high humidity and high temperature, which other vapor barriers cannot withstand.

Vapor barrier film solves problems by keeping tiny water droplets out of the way while also allowing it to "breathe."

Liquid rubber

This product is offered as a liquid bitumen-polymer agent. Following application to the surface, a "rubber" covering that replicates all of the wall’s nooks and crannies emerges. The rubber surface protects hydro, offers thermal insulation, and prevents moisture from penetrating.

Liquid rubber types:

1. Emulsion – applied by machine. Applicable to the floor for vapor barrier.
2. Emulsion applied to the floor manually.

Another use for liquid rubber is shielding the foundation from the street.

Installation of vapor barrier material when insulating inside a brick house

Brick walls are constructed with vapor barriers utilizing a variety of materials. These are membranes and films found within the building.

Foil-based materials can also be used. They possess reflective qualities. The foil side is inside the room in this instance.

A brick wall needs to be protected from both sides if mineral wool is used to insulate it from the inside. from the room side due to vapors seeping through the insulation and from the wall side due to condensation.

Penotherm, penofol, and alyuf are examples of protective materials.

Prepare the wall first by dusting it and clearing it of any sharp objects.

Then secure the vapor barrier, add insulation to the lathing that has been made, and place the vapor barrier back on top. The mineral wool is thus shielded from all sides.

Which side to put on the insulation inside the building: how to lay

Choose which side of the material to lay based on where it will be installed:

1. When laying insulation from the street side, the vapor barrier is fixed to the insulation – from the street side.
2. When processing the ceiling, roofing, antioxidant materials are used. They are fixed to the insulation.
3. If there is no additional fastening of the ceiling and roof insulation, then the material is fastened from below the rafters.
4. If thermal insulation is from the inside of the walls, then fixation is made from the outside of the insulation.

There are numerous materials that are used with identical surfaces on both sides. Consequently, it doesn’t matter which side of the vapor barrier is fixed.

Which side to fasten and nail

Nuances emerge when deciding which side of the vapor barrier to fix:

1. There are materials that have the same sides. Their use does not affect the protective functions.
2. The antioxidant insulator is placed with the smooth side towards the insulation.
3. Foil membrane – fixed with the shiny surface inside the room.
4. Film materials – smooth side towards the insulation.
5. When choosing a diffuse component, you need to study the instructions, since they can be double-sided.

What to glue

The vapor barrier can be fixed in a few different ways:

• use nails with wide heads;
• use a construction stapler;
• fix wooden planks on top of the layer at a certain distance.

Adhesive tape is used to glue joints in vapor barriers.

Features of vapor barrier of frame and wooden buildings

The house’s wooden walls are shielded from the elements by an interior and exterior vapor barrier. Primarily, this is required to safeguard wooden beams, as moisture causes them to dry slowly. The timber rots and deforms while it dries.

Installing a vapor barrier layer is essential in a wooden house because temperature swings and the emergence of humidity are possible. particularly during the fall and spring seasons.

Another technique is used to create a vapor barrier in the walls of frame homes.

How to lay correctly

The following steps are taken to create a vapor barrier between the street and the walls of a wooden house:

1. Layers are fixed to wooden beams with an overlap. All joints are sealed with tape or foil tape.
2. Next, the frame base for the insulation is installed.
3. After attaching the mineral wool, a water barrier is attached to the beams on top.
4. The final stage is the finishing of the house.

The vapor barrier should be fixed to wooden slats if the beams produce a level surface. Ventilation will result from this.

Interior vapor barrier of the home:

• a gap should be made using slats for ventilation;
• the material is attached to the slats;
• the next step is to erect a frame base for the insulation.
• after laying the insulation, the water barrier is fixed;
• the final stage is the finishing.

You must adhere to the following guidelines when installing a frame house’s vapor barrier material:

• use membranes, create a ventilation layer;
• vapor barrier is not installed on both sides.

A stapler is used to secure the material, and tape is used to stitch up the borders.

Is additional protection needed

Extra protection is not needed in a wooden house. However, materials like hydro- and wind protection are appropriate for frame buildings. It is fastened to the external coating. Then OSB, vapor barrier, thermal insulation, and finishing are put on.

Is it possible to lay several layers

This is not required because the vapor barrier material’s design ensures that it satisfies all of its purposes. Moreover, vapor barriers are not always the only materials used to protect the walls and insulation (waterproofing, wind protection, etc.).

Pay heed. Certain membrane types are made up of multiple layers. The walls in wet rooms will have extra protection thanks to this material.

How difficult is it to make a vapor barrier with your own hands

A house’s vapor barrier can be installed independently, even though it’s a crucial component in preventing the structure from collapsing. To accomplish this, abide by the guidelines:

1. You need to know how to properly carry out installation in specific cases (high humidity, wooden walls).
2. Before carrying out installation work, you should familiarize yourself with the technical characteristics of the selected material.
3. The roll must be cut precisely by measuring the correct length. The fewer joints, the better for the building.
4. The layer cannot be fixed simply with nails to the surface. Over time, the vapor barrier will tear and weaken. It is imperative to use either wooden slats or a stapler.

Aspect	Description
Correct Side	The smooth side should face towards the insulation, while the rough side faces inward towards the room.
Types of Fastening	Use staples or double-sided tape to attach the membrane securely to the frame or surface.
Installation Options	Overlap sheets by at least 10 cm, and seal the seams with special tape to prevent moisture leakage.

To prevent moisture damage to your walls, make sure a vapor barrier membrane or film is properly installed inside your house. You can optimize the efficacy of glue by selecting the appropriate side to apply it on, be it the rough or smooth side. The membrane will remain stable over time if it is properly fastened, whether with adhesive, staples, or another technique.

You can get long-lasting results by being aware of the different kinds of vapor barriers that are available and the best installation techniques. Investing the time to complete this task accurately will pay off in the long run, regardless of whether you’re working on new construction or retrofitting an older house.

Recall that a properly installed vapor barrier not only protects your walls but also, by halting the growth of mold and mildew, helps create a healthier indoor environment. These pointers will help you make your living area more comfortable and long-lasting.

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