This is how you process a vapour barrier

Vapour control and vapour barrier membranes are used to eliminate air flows and to protect constructions and insulation material against unwanted condensation. Air inside insulated spaces is normally warmer than outside air and can lead to increases in humidity. This can be caused by, for example, cooking or showering, although rainwater or elevated groundwater levels can also cause a lot of moisture, which starts to rise due to evaporation.

The created moisture will want to flow outside as vapor, which can cause condensation or construction decay if the wrong type of vapor barrier is used. But above all, moisture can cause insulation material to become moist, which means it will be less effective. That is why it is important to use a good vapour control or vapour barrier membrane to fully seal the inside of well-insulated constructions.

Attachment using staples
You can easily install vapor barriers with staples. Roll out the membrane and staple it in place under the construction. Because staples create perforations in the membrane, it is important to keep the number of staples to a minimum or to insert them where they will be covered by the next membrane overlap. To ensure an effective air seal, it is essential to tape over visible staples and overlaps using suitable tape.

Attachment with double-sided tape
If you want an airtight attachment without perforating the membrane with staples, you can also attach the vapor barrier with VAST-R® double-sided, VAST-R® Sealpro or VAST-R® Butyl tape. Apply the double-sided tape to the underlying construction, apply firm pressure and then remove the release layer. Roll out the membrane and press it against the double-sided tape. Carefully rub over the tape afterwards to ensure effective bonding.

Airtight seal
Overlaps and damage must be taped off using suitable VAST-R® tape or TAFTEX® tape. You should use VAST-R® Sealpro or VAST-R® Butyl tape for connections to walls or floors. Does the membrane feature openings or joints? Then use Tyvek® Flexwrap tape to easily make them airtight.