Permavent Ltd

Permavent is a UK manufacturer specialising in high performance roofing underlays, membranes and low pitch roofing systems, with over 20 years of experience across both new build and refurbishment sectors.

The company has built a strong reputation for delivering reliable, compliant and practical solutions that respond to the demands of modern roof design, particularly in moisture management and long term durability.

Working across residential, social housing and commercial construction, Permavent supports architects, specifiers, contractors and developers in the design and delivery of robust roofing systems. The focus is not just on individual product performance, but on how each component contributes to the overall effectiveness of the building envelope.

Technical expertise and specification support:

A key part of Permavent’s approach is providing technical support throughout the design and specification process. A nationwide technical team works directly with specifiers to guide compliant roof design in line with current standards, including BS 5534 and BS 5250.

Permavent recognises that a well developed specification at the outset is critical to the success of any project. The specification team works alongside architects, housebuilders, contractors and designers to develop tailored solutions that meet performance requirements, ensure compliance and reduce risk on site.

Support goes beyond product selection. It includes detailed advice on roof build ups, condensation risk, ventilation strategies and installation best practice. Clear and practical guidance is provided from early design stages through to on site support, helping to avoid costly changes, minimise delays and keep projects progressing as planned.

As performance requirements around airtightness, energy efficiency and moisture control continue to increase, this level of input is becoming essential. Early engagement helps reduce risk, avoid common specification issues and ensure the proposed system performs as intended.

This is particularly valuable on refurbishment and heritage projects, where existing structures often present more complex challenges.

Proven performance at scale

Permavent products are widely used across the UK, across a range of building types and exposure conditions. In 2025 alone, over 25 million square metres of Permavent roofing underlay was installed.

This level of use reflects the confidence placed in the products by contractors and developers. Consistent performance across different project types has helped establish Permavent as a dependable choice for both new build and re roofing applications.

Independent testing and certification

Permavent roofing underlays are independently tested and UKCA, CE and BBA certified, with the exception of NB145. This provides assurance in terms of durability, performance and compliance, which is critical when making specification decisions.

Testing covers key characteristics such as water resistance, tensile strength, tear resistance, vapour permeability and resistance to ageing. These properties are essential to the role of roofing underlays, which must act as a secondary barrier to water ingress while allowing moisture within the roof structure to escape.

Independent verification ensures that performance claims are supported by robust data, giving specifiers confidence in the suitability of the products.

Moisture management and roof design

Managing moisture within the roof structure is a critical part of modern roof design and a central focus of Permavent’s product development. Poor moisture control can lead to condensation, mould growth, timber decay and reduced thermal performance.

Permavent roofing underlays are designed to support controlled moisture movement within the roof build up. Air open, vapour permeable membranes allow moisture vapour to escape while maintaining a weatherproof external layer. This helps reduce the risk of interstitial condensation and can often remove the need for additional ventilation.

Product range

The Permavent range is designed to meet key performance requirements across roofing and walling applications. It includes breathable roofing underlays, wall membranes and low pitch roofing systems, offering solutions for moisture control, airtightness and weather protection.

Low pitch roofing solutions

The Easy Roof System provides a tested solution that allows materials to be used at reduced pitches while maintaining weather tightness. This creates greater design flexibility without changing the external appearance.

The system has been independently tested and received industry recognition, including the Queen’s Award for Innovation in 2014. It's development reflects Permavent’s focus on solving practical design challenges through engineered solutions.

Sustainability and long term performance

Sustainability in construction is increasingly focused on whole life performance. Durable, well designed building envelopes can reduce maintenance and extend the life of a structure.

Permavent products support this by contributing to the long term performance of roofs and walls. Effective moisture management helps protect structural elements, while robust materials ensure consistent performance over time.

Permavent has established itself as a trusted manufacturer of roofing underlays and systems, supported by over 20 years of technical expertise and proven performance.

Through independently tested products, nationwide technical support and a focus on practical installation, the company provides solutions that meet the demands of modern construction.