Icopal’s new Monarperm Breathe membrane range is made up of high performance pitched roof underlays that the company says are ideal for use in warm or cold, ventilated or non-ventilated pitched roof constructions.
Suited to installations directly, fully-supported over insulation boards, or draped unsupported over rafters, Icopal says the membranes – Breathe AllZones, Breathe Two and Breathe One – are virtually unaffected by regular conditions within a pitched roof space.
They consist of a vapour-open microporous film that’s thermally bonded between two outer layers of spunbonded polypropylene. The outer layer forms an external wind and waterproof barrier with the central microporous film acting as a one-way valve. This allows vapour to escape and prevents water penetration through the membrane whilst the inner white surface protects against abrasion and provides a high level of light reflectance.
With low resistance to the passage of moisture vapour, the risk of condensation is lowered whilst remaining airtight and watertight.
This explains the highly efficient guarding against wind driven rain or snow and the ability to track any water safely down the gutters and away from the construction.
BS 5534:2014 specifies that all roofing membranes are tested at defined batten centres for most interlocking tiles, and against various levels of wind speed. This is to avoid ‘ballooning’ of the underlay as it can impact upon slates or tiles causing them to dislodge. The standard divides the UK into five zones according to wind pressure.
There are three products in the Breathe range. Breathe AllZones is suitable for zones 1 to 5 at 345mm batten centres without the use of tape. Breathe Two can be used without tape in zones 1 and 2 at 345mm batten centres, and Breathe One is suitable for zone 1 at 345mm batten centres without tape.