Vapor barrier using aluminum foil                    

Vapor barrier using aluminum foil

Vapor barrier using aluminum foil

The vapor barrier and vapor retarders

Renovation or new construction often raises the question of whether a vapor retarder or a dampremmende folie (Vapor barier foil) is more appropriate. Insulated building parts can be sealed with either alternative.

An advantage of a vapor barrier is that it prevents moisture from escaping, so she is steam-tight.

On the other hand, water vapor can escape in small quantities through a vapor retarder.


There is often talk about SD values in this context. Using this Sd value, we can determine how long it takes water vapor to migrate through an airtight component based on the diffusion-equivalent thickness of the air layer. For example, if the value is 4 m, then this means that water Vapor passes just as quickly through an airtight component as it does through an air layer that is 4 m thick. The Sd value of a vapor barrier is normally over 1,500 m. All values below this are considered vapor retarders.

In order to better protect the thermal insulation against moisture penetration, various foils can be used for the Vapor barrier. Fiberglass insulation can, for instance, be laminated with aluminum foil. As a result, a vapor barrier is created.  Since the 1970s, aluminum foil has been used as a vapor barrier.

Aluminum foil can be used as a vapor barrier and as a vapor retarder, for example when perforated aluminum foil is used.

Is aluminum foil useful as a Vapor barrier?

Insulation for roofs using aluminum foil

Despite the fact that aluminum foil ages faster than other materials, it makes sense to use it. Aluminum foil can be used to produce an inexpensive vapor barrier. Make sure that aluminum foil is glued over a large area when using it.

Swimming pools, saunas, and other wet areas in public places are usually sealed with aluminum foil. Insulating the roofs of houses should also utilize aluminum foil. Vapor barriers are essential in this process. These prevent moist air from entering the house.

the roof construction can reach.

Aluminum foil vapor barrier

Thermal insulation should always be installed on the room side with a vapor barrier made from aluminum foil. It cannot work otherwise. Many aluminum foils have labels that must point towards the interior of the room during processing in order to ensure the foil is processed correctly. Using high-quality aluminum foils as a Vapor barrier is an excellent choice because they are extremely durable and inexpensive.

Among all materials, plastic and aluminum foil are most commonly used as vapor barriers. Plastic is usually used as a vapor barrier. The web width of a standard roll of film is 1.50 m. The length of most rolls is 50 or 100 meters. As an aluminum foil, it is extremely resistant to tears, vapor diffusion-proof and tear-resistant. Vapor barriers laminated with PE and aluminum are ideal for vapor-tight constructions. Installing a Vapor barrier made from aluminum foil will provide optimal thermal insulation. Aluminum foil provides an additional 10% thermal insulation.

Vapor control layers: What are the applications?

A Vapor barrier must be installed professionally if there is to be no moisture damage. The reason for this is that construction with a Vapor barrier can only be sealed with aluminum foil with some difficulty. However, in most cases, the fault lies with the workmanship rather than the foil.

It is often the connections that are troublesome when the aluminum foil is not applied correctly. It is possible, however, that the film can also be damaged when the sockets are attached. If you want to erect a vapor barrier in the attic, sauna, pool area, steam bath or cold store, be careful with the aluminum foil.

If the thermal insulation is still damp during installation, this must also be checked in advance. Thermal insulation in this case should not be allowed to dry completely until it is completely dry. Unless aluminum foil is used, the water from the components won’t be able to evaporate. Because of the sorption capacity of the material, air-dried components also contain several liters of water per square meter. Whenever aluminum foil is used as a vapor barrier, it should always be consulted by an expert. With everything properly laid out, aluminum foil provides a high-quality barrier.

The films can be customized to suit any structure and are available in different sizes and lengths. Especially suitable are multilayer metallization films. They reflect heat energy and add an extra layer of insulation.

Read Also: Types of Formwork Used in Concrete Construction

Pro / Contra

Processes that are simple

Aluminum foil has the biggest advantage as a Vapor barrier in that it is easy to process. It is also very inexpensive compared to other materials. Moreover, when a Vapor barrier is implemented, the aluminum foil increases the thermal insulation.

Reflective heat and radiation

Up to 99% of electromagnetic radiation is shielded by aluminum foil Vapor barriers. They also reflect half the heat. Aluminum foil sheets must be laid neatly, which is a small disadvantage. The foil sheets aren’t airtight otherwise.

Be careful!

You need to be very careful with the aluminum foil since it can tear easily. After it has been properly bonded, however, it offers an optimum vapor barrier. Aluminum foil can be used as a vapor barrier on all unventilated and ventilated roofs, i.e., warm and cold roofs. Apartments with attics or facades can be insulated with it.

Most films are water- and wind-resistant, as well as vapor-proof. A Vapor barrier can reduce a house’s energy costs. Heat is prevented from escaping through a good-quality film while the insulation is protected from moisture. It can also be very useful to install insulation on the rafter if necessary. As an example, when the roof has already been removed or when the renovation is underway. Afterward, the Vapor control layer is attached to the underside of the roof insulation.