innovative construction products

Search

Case Study

Heritage slate meets modern low-pitch roofing performance.

A traditional property within the historic Westonbirt Estate in Tetbury, Gloucestershire, was reroofed by Severnside Morley, using the existing natural Welsh slates in conjunction with Permavent Easy Slate. The property has a strong connection with the surrounding estate and its historic buildings. Westonbirt House was rebuilt in the 19th century, with the wider gardens and surrounding parkland having significant historic interest and were listed Grade I in 1986. Rather than changing the visual character of the roof, the project retained the original roofing material, with the Permavent Easy Slate system providing a discreet solution beneath it. The approach demonstrates how modern roofing technology can be used to address the practical requirements of a low-pitched roof while retaining traditional materials and appearance.

View products used in project

Location

Westonbirt Estate Yard, Tetbury, Gloucestershire

The Project

The project involved the removal and reinstatement of approximately 200m² of existing natural Welsh slates. The roof presented a particular challenge, with a pitch of approximately 12-14°. A conventional approach to natural slate roofing would have presented a significant technical challenge. The project team therefore explored the use of Permavent Easy Slate, a low-pitch slate roofing system designed to enable double-lapped natural slate roofs to be installed at shallow pitches. Rather than replacing the existing Welsh slates, the project team carefully removed and retained the original slates for reuse. The objective was to retain as much of the existing roofing material as possible while providing the roof with a modern secondary layer of weather protection.

Permavent in Action

Following the stripping of the existing roof, Permavent DRY+ was installed as the vapour-permeable underlay, together with butyl tape and counter battens. Permavent Easy Slate was then incorporated into the roof build-up to provide a suitable solution for the shallow pitch. The system is designed to reduce the risk of water ingress associated with low-pitch double-lapped slate roofs while helping to keep the batten cavity dry. The reclaimed Welsh slates were then reinstated, allowing the original roofing material and appearance of the building to be retained. The combination of the existing natural slate and Permavent Easy Slate provided a practical solution to the shallow roof pitch while remaining sympathetic to the character of the property.

The Result

Following completion, the project qualified for Permavent’s 40 Year Guarantee, giving both the contractor and client additional confidence in the long-term performance of the roofing system. The completed project successfully combines reclaimed natural Welsh slate with modern low-pitch roofing technology. Approximately 200m² of existing slates were removed, retained and reused, preserving the established appearance of the property while the Permavent Easy Slate system provided a modern solution for the challenging roof pitch. The project demonstrates how careful removal and reuse of existing materials, combined with the appropriate roofing system, can help preserve the character of a traditional building while meeting the practical requirements of a low-pitched roof.

Permavent Easy Slate

Patented low pitch slate roofing system

Low pitch roofing system as low as 10°
Extends the life of the roof by keeping battens dry
Creates new areas for slate application
40-year product guarantee

Permavent DRY+

High performance vapour-permeable underlay

Vapour permeable
Integrated tapes, suitable in all UK wind zones

MORE CASE STUDIES