Roofing Membrane

Roofing membrane is typically a flexible, lightweight sheet material installed beneath the roof tiles, slates, or metal sheets. Its main function is to act as a secondary barrier against water penetration, often referred to as a breather membrane or underlay. It protects the roof structure and the interior of the building from wind-driven rain, snow, and dust that may get past the main roofing material.

How does roofing membrane work

It works by being watertight but vapour permeable meaning it allows moisture vapour from inside the building to escape to create a well-ventilated and dry environment. The Cromar Vent 3 Light Roofing Membrane is an ideal solution for a variety of applications including residential and commercial roofs. 

Benefits of updating your shed felt 

Keeping your shed roof watertight is a simple way to protect the contents of your shed from water damage and can be a simple DIY task, but refreshing your shed roof felt can also;

• Extend the lifespan of the shed structure, preventing rot and decay
• Enhance insulation, keeping the shed cooler in summer and warmer in winter
• Provide a more aesthetically pleasing finish to the shed roof
• Reduce the likelihood of costly internal repairs due to water ingress

Roofing membrane FAQ

What is the difference between a breather membrane and a non-breather membrane?

Breather membranes (also known as vapour-permeable underlays) are designed to be waterproof but allow moisture vapour to pass through, letting the roof structure ‘breathe’ and preventing condensation build-up. Non-breather membranes are usually impermeable to vapour, requiring a traditional ventilated cold roof space to avoid condensation issues. Most modern construction uses breather membranes for ease and efficiency.

Do I need a roofing membrane under roof tiles?

Yes, when it comes to building or renovating your home, a roofing membrane is an essential component of a tiled or slated roof. It acts as a secondary barrier against wind-driven rain, snow, and dust, protecting the roof structure and interior from water if the roof tiles are compromised or damaged. It also helps to channel any water that gets past the tiles down to the gutter.

How long does a roofing membrane last?

The lifespan of a roofing membrane can vary significantly depending on the material quality, installation, and specific environmental conditions. High-quality, modern breather membranes are typically designed to last for the lifetime of the roof covering, often 20 to 40 years or more. Always check the roofing merchant’s guarantee.

Can I use roofing membrane on a shed roof?

While roofing membranes are primarily designed for main residential and commercial roofing applications, they can be used on shed roofs. However, shed roofs often utilise heavy-duty shed felt as a simple, durable, and cost-effective waterproofing solution.