Five Considerations When Selecting Roofing Membranes
Sometimes called single-ply membranes, roofing membranes are roof coverings that are applied to a roof to provide the waterproofing layer.
They play an important role in the roof build-up and ensure that the building is water-tight. But what types of roofing membranes are there? And which is the most suitable for your project?
In this article, we discuss some of the key differences between different roofing membranes, helping you decide which roofing membranes might be the best fit for your project.
Not All Roofing Membranes Are The Same
The difference between roofing membranes lies not just in the various brands available, but also in the different materials used to make them. Each material has its advantages, and it’s helpful to understand a little more about each type.
EPDM
These roofing membranes are made from synthetic rubber and can be fully adhered or mechanically fixed. In the UK, CARLISLE®'s HERTALAN® EPDM waterproofing system is the only one of these roofing membranes that can be installed using induction technology.
Bituminous
These are supplied as a sheet of bituminous material and are often installed as a ‘torch-on’ system using the flame from a hot torch to melt the bitumen and adhere the roofing membrane to the roof.
EPDM/bituminous hybrid
There is only one roofing system that combines the durability of a bituminous material and the elasticity of EPDM in a single roofing membrane: RESITRIX® from CARLISLE®.
TPO
TPO, or thermoplastic polyolefin, is a roofing material made from a blend of polypropylene and elastomer. These roofing membranes, such as CARLISLE®’s SURE-WELD® TPO, are particularly popular in the US market, and are known for their elasticity and pale colour.
PVC
PVC single ply roofing membranes are still commonly used in the UK but they often have a limited lifespan due to shrinking and cracking, and there are also environmental concerns about the potential for leaking plasticisers.
Roofing Membranes Have Different Fixing Methods
When considering various roofing membranes, it’s important to think about buildability and the implications of different fixing methods.
Mechanical fixing
This involves securing membranes using physical fasteners.
Loose laying with ballast
The loose-laying layers are secured in place by means of an appropriate ballasting solution, such as gravel with a grain size of 16 / 32.
Ballasting for flat roofs is determined according to DIN EN 1991-1-4. The roof structure’s load-bearing capacity must be taken into consideration according to the loads to be transferred. A suitable protective fleece is required to create a separating layer between the ballast and the waterproofing system.
Fully adhered roofing membranes
These are installed by applying a specialist adhesive to the roof substrate to fix the waterproofing layer.
Self-adhesive roofing membranes
They are installed by removing the release film to expose the self-adhesive layer. Flame-free hot air welding equipment is then used to seal the laps.
Induction installation
This method can be used to install CARLISLE®’s HERTALAN® EPDM and SURE-WELD® TPO roofing membranes, enables the fixings and roof covering to be removed cleanly at the end of the its service life so that it can be recycled or re-used, enabling true circularity.
Torch-on roofing membranes
These require the use of a naked flame. This system is commonplace for bituminous roofing membranes and requires a meticulous approach to health and safety, including a two-hour fire watch at the end of every day on site.
Installation of all of CARLISLE®’S roofing membranes is flame free, and we provide installation training to ensure that, regardless of the installation method, our roofing membranes deliver their certified performance.
Can Roofing Membranes Be Used For Green Roofs?
With biophilia becoming an increasingly popular design feature for both residential and commercial buildings, it's important to consider whether the roofing membranes you are considering for your green roof are suitable for the loadings of a green roof and if they offer sufficient root resistance.
All of CARLISLE®’s membranes are root resistant and compatible with green roof specifications. Find out more about Green Roof Sytems by clicking the button below.
Which Roofing Membranes Offer An Extended Service Life?
When correctly specified and installed, roofing membranes can provide an extremely robust and durable waterproof covering, making them an ideal, low maintenance, sustainable roofing solution.
EPDM membranes, including the HERTALAN® EPDM and the RESITRIX® EPDM and bituminous hybrid roofing system from CARLISLE®, offer a service life of at least 70 years. This is because they provide excellent resistance to U/V and freezing conditions, along with permanent elasticity and high levels of durability.
TPO also offers a long service life, for example, CARLISLE®’s SURE-WELD® TPO system remains flexible in cold temperatures and reflects heat instead of absorbing it, providing both weather protection and weather resistance for a service life of at least 30 years.
Can Roofing Membranes Contribute To A Building’s Sustainability Credentials?
One of the biggest factors in a building’s sustainability performance is the longevity of the building fabric.
What’s more, these membranes also protect the building from water ingress, helping to maximise the service life of other materials used in the building envelope and interior fit out.
CARLISLE®’s roofing membranes have excellent sustainability credentials:
HERTALAN® is both durable and recyclable, delivering a cradle-to-cradle approach to circular sustainability.
RESITRIX® is 100% non-toxic and produced with EPD (Environmental Product Declaration) certification and DGNB (German Sustainable Building Council) compliance.
SURE-WELD® TPO has no plasticisers, no halogens, and no heavy metals. Their pale, reflective surface also reduces the urban heat island effect.
If you’d like to know more about our range of high performance roofing membranes, get in touch with our team on 01623 627 285.
Lancaster House, Millenium Business Park
Mansfield, Notts NG19 7DW
T +44 1623 627 285
E info.uk@ccm-europe.com