Question 1

What is the difference between non-breathable and breathable roof membranes?

Accepted Answer

Non-breathable roof membranes are waterproof barriers that prevent moisture vapour from escaping, potentially causing condensation and dampness inside the roof. In contrast, breathable roof membranes allow moisture vapour to escape while blocking water ingress, reducing condensation, mould, and rot, and ensuring better indoor air quality and roof longevity. Choosing the right membrane depends on your building needs and climate conditions for optimal moisture management and weather protection.

Question 2

What is the best breathable membrane for roofs in the UK?

Accepted Answer

The best breathable roof membrane in the UK offers a high level of water resistance combined with excellent vapour permeability, suited to local weather conditions. Look for membranes with proven durability, ease of installation, and strong moisture control to prevent condensation, mould, and structural damage. Brands like Tyvek and Klober offer breather roofing membranes that are highly recommended for energy-efficient, long-lasting roof systems. Breathable roofing membranes often come in lengths of 50m but other Always choose a membrane that complies with UK building regulations and is suitable for your specific roof type.

Question 3

What is the difference between a ‘vapour control layer’ and ‘breather membrane’?

Accepted Answer

A vapour control layer (VCL) is a semi-permeable film designed to restrict moisture vapour from entering roof or wall cavities, helping to prevent condensation and dampness. Meanwhile, a breather membrane is a highly permeable material that allows moisture vapour to escape from within the building while providing excellent weatherproofing. Essentially, a VCL controls internal moisture, whereas a breather roof membrane manages external moisture and airflow, contributing to a healthier, more durable roof system.

Question 4

What lengths do breathable roof membranes usually come in?

Accepted Answer

Breathable roof membranes are commonly available in 50m rolls, offering large coverage with fewer joints for efficient installation. Depending on the project size, some brands also supply shorter rolls of 25 meters or longer options up to 100 meters. The 50m length is widely preferred in the UK, providing a cost-effective solution for roof protection while ensuring optimal moisture management and weatherproofing.

Breathable roof membranes

A.proctor Roofshield Breather Membrane 50 X 1m X 0.75mm

Tyvek Supro Breather Membrane Felt Underlay 1m X 50m (50m2/roll)

Tyvek Supro Breather Membrane Felt Underlay 1.5m X 50m (75m2/roll)

Tyvek® Supro Plus, With Integral Tape, Breather Membrane 1.5m X 50m

Permo Forte 1.1m x 50m

Buildbase Breather Membrane 50 X 1.5m

Buildbase Breather Membrane 50 X 1m

1500mm X 50m Primaguard Breathable Membrane 115GSM

Easy Trim Ultra Breather Membrane 50m X 1m

Easy Trim Grafter Breather Membrane 50m X 1m

Easy Trim Ultra Breather Membrane 50m X 1.5m

Klober 10K Slate Vent 600 X 300 X 60mm Slate Grey

Klober Permo Extreme RS SK Blue SK? 75m

Cromar Vent 3 High Performance Breathable Membrane 50M x 1M Grey

Procheck FR200 1.6 x 50m