Vapour Control Layers

Vapour control layers, also known as vapour control barriers, are very important in the building envelope to ensure that unwanted moisture and water vapour don’t enter the building or transfer between layers. If water vapour passed through timber frame walls for example and met insulation, the water vapour could cause the insulation to deteriorate and in turn the timber walls would rot and sag. Vapour control layers can help reduce interstitial condensation that can result in a lot of damage and repair costs.

Vapour barrier

Vapour barriers are a specific type of vapour control layer that stop the movement of water vapour. Vapour control barriers prevent moisture transmission and can be installed in walls, roofs and floors to aid the protection of the building. Heavier duty vapour barriers are available for kitchens, bathrooms and other moist areas such as Novia 1200 gauge whereas Novia 500 will suffice for areas such as domestic living rooms or hallways. Typically manufactured from polythene, vapour barriers are important in timber frame constructions too to prevent wood from rotting and structural damage.

What’s the difference between a vapour control layer and a vapour barrier?

A vapour control layer and a vapour barrier both offer a building structure different features. Some buildings need to have the movement of vapour and air completely restricted but some buildings, like most timber frame structures, require some restricted movement to allow for the correct airflow for longevity and integrity of the building. In timber frame structures for example air and water vapour needs to move from inside of the building to the outside, in a controlled way, so that the timber doesn’t become damp or rotten.

A vapour control layer limits the movement of air and water vapour through the membrane, known as being air permeable and vapour permeable. A vapour barrier, or vapour control barrier, eliminates the movement of any vapour or air from passing through the walls of the building. Use of a vapour barrier must be very carefully considered as this could lead to a build up of humidity and condensation within layers of insulation.

Products in Vapour Control Layers:

Showing 1-24 of 55 products

Showing 1-24 of 55 products