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Roofing ProductsFlat Roofing Breather Membrane

Flat Roofing Breather Membrane

Best protection against condensation for construction and roofing

Permaroof breather membranes offer high performance against condensation in all types of roofing applications. The only 3-layer roofing membrane to pass the air permeability test conducted by the Building Research Establishment (BRE), Permavent offers one of the best options on the current market.

We stock a range of Permavent breather membranes in two sizes – 1m and 1.5m width in black or white.


Breather Membrane 1m

Breather Membrane 1.5m

Breather Membrane 1m Breather Membrane 1.5m
Buy 1m Breather Membrane Online Buy 1.5m Breather Membrane Here"

Why use breather membrane in roofing?

The roof space is often where the heat is most concentrated and lost in a building as the hot air rises from the floors below. Aside from the significant heat loss, it can also lead to the formation of condensation across the entire roof on the inside caused by the differences in air temperature between the outside and the inside. Installing breather membrane helps to minimise condensation build-up in any type of roofing installation. If condensation is allowed to form within the roofing, it isn’t long before wood decks become wet and damage sets in.

In the worst cases, uninsulated flat roofing can be destroyed by wood rot where condensation has been present with no means of escape. Simply installing breather membrane can immediately reduce heat loss by up to 25% and can eliminate thermal bridges at critical points such as eaves and across timbers.

Increasing energy efficiency

High quality breather membranes help to reduce heat loss across the entire roofing system, whether pitched or flat, domestic or commercial. The immediate benefits to this are clear as straightaway, the home gains a better energy rating.

As the moisture in the property is also reduced, this creates a healthier, drier environment and can prolong the lifespan of the roofing. Permavent membranes encompass the latest medical industry technology to encapsulate a high grade hydrophobic film within polypropylene layers. Unlike rival brands, Permavent breather membrane combines a 3-in-1 process to improve the integrity and ultimately quality of the membrane. This single process ensures superior breathability and flexibility over the long term.

All Permavent membranes are certified for use in all types of roofing and walling applications and conform fully with:

  • BS 5250: 2011 Code of practice for control of condensation in buildings.
  • BS 5534: 2014 Code of practice for slating and tiling.
  • BS 8000-6: 1990 Workmanship on building sites.
  • BS EN 1991-1-4; 2005 +A1: 2010 +UK NA.
  • BS EN 13859: Flexible sheets for underlays.
  • BS EN 13501-1 2007.

What about ventilation systems for concrete roofing?

Concrete roofing also needs ventilation across the entire surface. Condensation and moisture are typically always present in some form in a concrete roof, whether old or new. Green (new) concrete should be left to cure for at least three weeks before covering with any kind of membrane.

Permaroof stock accessories to handle condensation and moisture. This type of ventilation system provides an escape route for heavy moisture in concrete roofing. The flat roof aerator sits on top of the bare concrete beneath a waterproofing membrane and insulation. Once membrane is sealed over the base of the aerator, a flue is created to draw the moisture away from the concrete via a series of ribs that encourage the movement of the water vapour.

Find out more about the flat roof aerator from Permaroof.