Vapour And Air Permeable Membrane

Using a Vapour And Air Permeable Membrane (VAPM) in your construction project is a great way to prevent water from entering your building. It’s also a way to make your home more energy efficient. The membranes have a lot of advantages, including being breathable and having a vacuum control layer.

Breather membrane

The term ‘breather membrane’ refers to a vapour and air permeable membrane used to protect buildings from the dampness and mould that can build up. They can be installed against the inside face of an external wall or in a roof structure.

Breathable variants do not require the same level of ventilation as non-breathable products. However, some may still need a ridge ventilation system. Typically, these breathable membranes are based on polypropylene or engineered plastics.

To be effective, breather membranes must be installed correctly. A good air tightness and a low water vapour resistance are essential for a roof breather membrane to function properly. In addition, the eaves support tray should be fitted correctly and the joints should be sealed.

There are two types of breather membranes: the water resistant and the water permeable. Water resistant membranes are ideal for framed wall constructions. On the other hand, the water permeable type is most suitable for tiled roofs.

Vapour control layer

A vapour control layer of air permeable membrane is a product used in building construction to minimise condensation. Condensation is the result of warm moist air rising. This moisture can be a health hazard and cause mental and physical problems.

If condensation occurs, the moisture can collect on the outside of a building. This can lead to mould forming, which can be hazardous. For example, it can cause asthma and a host of other illnesses. It can also reduce the energy efficiency of a building.

A vapour control layer can be installed in the loft and roof of a home. In these cases, the membrane is installed on the warm side of insulation. The membrane is usually aluminium or polyethylene.

It is important to keep the vapour membrane warm enough to stay above the dew point on the exterior side. The membrane must also be able to resist penetration by vapour. Ideally, the membrane should be sealed from the inside and outside.

Synthetic underlay

If you’re installing a new roof, you’ll need a roofing underlay. The underlay is a semi-breathable membrane that provides a protective coating for the roof assembly. It also helps prevent water intrusion.

You’ll want to choose a synthetic underlay that is breathable. This is a good idea for any homeowner concerned about moisture infiltration.

There are two types of breathable membranes. One type is called a vapor permeable underlay. These underlayments are primarily used for roof ventilation. However, they are more expensive than vapor impermeable underlayments.

When shopping for underlayment, you’ll need to consider a number of factors, including cost, lifespan, and resistance to wind. The best option will strike the balance between thickness and affordability.

Generally, you’ll find that synthetic underlayments are more expensive than asphalt felt. They’re about twice as expensive. But they’re also less damaging to install. And they offer better traction.

Unlike felt, synthetic underlayments are not prone to wrinkling. Depending on the quality of the material, you can leave them exposed for up to six months.