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Why a vapour barrier?

A vapour barrier or vapour retarder is used in the building industry to prevent water vapour from precipitating as condensation in the thermal insulation or flooring. In the laminate flooring sector, the vapour barrier is a film that is usually made of polyethylene (PE film). It prevents moisture from penetrating through the subfloor into the laminate flooring.

How does this moisture develop and what are the consequences?

Under certain climatic conditions, water vapour can develop due to temperature differences in the subfloor. This condenses in the floor area as condensation water and can penetrate the laminate floor. This can cause damage to the laminate; for example, the floor can swell or unsightly ripples can form.

What kind of subfloor requires a vapour barrier?

Especially with mineral subfloors such as screed, asphalt or concrete, a vapour barrier film must be laid. This is because these substrates consist partly of water – so rising moisture is to be expected under certain climatic conditions. To prevent this water vapour from condensing on the laminate flooring and causing structural damage, a vapour barrier should be laid.

Laying the vapour barrier under laminate flooring

The vapour barrier is laid under the laminate flooring and under the impact sound insulation. This means that the film must be laid in a trough-like manner in the first step. The vapour barrier is spread to overlap the edges by approx. 20 cm. To seal everything optimally, the ends and the overlap should be sealed with adhesive tape – for example, with a special aluminium adhesive tape for vapour barriers. An alternative to the vapour barrier is an insulating underlay with an integrated vapour barrier. This is a time-saving alternative, as it eliminates an entire work step.

Take a look at the insulating underlays for laminate from LOGOCLIC® and find out about the right products for your project.