1) Is Breathable Roofing Membrane waterproof?
Yes. Breathable membrane is extremely waterproof and due to its composition, also protects against snow and dust. If laid correctly, it will protect against rain or snow blown by the wind and prevent it from getting through gaps in the roof tiles. Our breathable roofing membrane is BBA Approved and is a low resistance membrane (LR) allowing moisture to transfer into the batten space above. It is vital that there is sufficient air movement for any built-up condensation to escape. WRAPTOR has a vapour resistance of less than 0.25MNs/g for design purposes.
2) How Long Will It Last?
Breathable roofing membranes can last a lifetime, depending on the product and manufacturer guidelines. If you do need to replace your roofing membrane, it can cost anywhere between £2,000 and £7300+ (the majority of which is the labour required to remove and reinstate the roof tiles) (checkatrade.com). The first sign of a damaged roof is often a leak, where the membrane has been breached. If you suspect an issue, it is a good idea to call in an expert, as a patch repair can be far cheaper than replacing the entirety of the membrane.
3) Do You Need To Use Physical Roof Ventilation With Breathable Roofing Membrane?
Not necessarily. However, according to British Standard BS 5250 & NHBC, it is recommended to use additional ventilation solutions such as eaves, ridge or tile options. It is also essential to ensure the manufacturer of the breather membrane is a British Board of Agreement (BBA) (such as WRAPTOR) or Building Research Establishment (BRE) certified product in order to ensure the suitability of the vapour permeable underlay for use within a roofing structure.
4) What Thickness Of Membrane Is Available?
Roofing membrane is available in a variety of thicknesses measured using GSM. This stands for ‘Grams Per Square Meter’. The higher the value is often an indication of the physical thickness of the material. Higher GSM roofing membranes are used where harsher wind conditions occur. This is dictated through different ‘wind zones’:
|Wind Uplift Pressure|
|250mm Batten Gauge (batten restrained lap)||345mm Batten Gauge (taped lap)||250mm Batten Gauge (taped lap)|
|Zones 1 to 2||Zones 1 to 2||Zones 1 to 5|
|Zones 1 to 3||Zones 1 to 3||Zones 1 to 5|
|Zones 1 to 3||Zones 1 to 4||Zones 1 to 5|
5) Can You Purchase The Entire Quantity Required?
With manufacturing delays due to Covid-19, it is important that you can actually purchase enough roofing membrane for your project. If the weather is unpredictable, delays can cause problems to both progress and water inset in the roof. Make sure that the supplier you choose has actually got stock available for dispatch to avoid these problems.
If you are looking for a breathable roofing membrane, BBA approved and with options for different wind uplift pressures, then take a look at our range of WRAPTOR breather membranes. If you need a quick estimate for the cost of your project, head over to our roofing membrane calculator. You can either buy online or submit a quote and one of our team will get back to you shortly.