Sika Sarnafil roof refurb gives church new lease of life

Severe rainwater leaks in the auditorium at Bracknell’s Kerith Community Church were causing big problems and forcing events and activities to be cancelled.

Having already completely re-slated the roof once before, the Kerith Centre management team knew it was time for a change, with the help of Sika Sarnafil and Owlsworth Roofing.

Kerith Community Church’s imposing auditorium space sits below a pitched, fan shaped roof structure, visible some 16 metres above at its highest point. Due to its unusual shape, a certain type of rain coming from one particular direction would breach the combination of slates and lead-lined gutters, resulting in water landing on the very centre of the auditorium stage.

Local architects Allen Associates decided that a seamless, durable single ply solution would suit the project and offer the church protection for years to come. Allen Associates, alongside successful tenderer, Owlsworth Roofing, chose a Sarnafil Plus roofing system thanks to the wide-ranging support services it offered and Sika Sarnafil’s high performance products.

Working alongside Owlsworth, who had an exceptional knowledge of the roof from photos, drawings and inspections, the Sarnafil Plus technical team created a bespoke specification for the pitched roof – a fully adhered system including Kingspan insulation, Sarnavap 5000E SA (a self-adhered vapour control layer), and Sika Sarnafil G410-18ELF Lead Grey membrane.

The project presented a number of trials for Owlsworth, but the roofing contractor rose to the challenge. The scope of works involved the complete removal of all slates, battens, counter battens and insulation, all secured to the slope with wide range of fixings. The direction of the fan shaped roof structure meant that the all stripped materials, new materials and personnel had to go down through the heart of the church, into a central courtyard and out to the carpark via narrow corridors.

Peter Mably, Director of Owlsworth Roofing, explained:

“Being a pitched roof, the 22 degree angle of the slope had an effect on the way in which the works could be carried out. It was possible to stand on most of the layers of both the old and new roof covering when it was dry but less so when it was wet! Health and safety amounted to 45% of the cost of the project.”

With the structural timber deck also acting as the internal ceiling the client didn’t want to see any fixings visible from below. Throughout the project, fixings needed to penetrate the timber deck sufficiently far enough to secure the roof covering but never to penetrate the underside. The new cable-based fall restraint system was carefully designed using a series of timber boxes secured to the deck so that the bolts needed to attach the system’s posts only penetrated the box and could not be seen from below.

Peter added

“All work was carried out while life continued as close to normal as possible at Kerith Community Church, with the building remaining fully open throughout the duration of the project. Although it was a challenging project, the finished results using the Sarnafil G410-18ELF Lead Grey membrane looked fantastic and the roof was awarded a 20 year guarantee from Sika, so the client can trust that they won’t have to worry about the roof for many years to come.”

For more information on Sika Sarnafil’s products and services, call 01707 394444, email sarnafilroofing(Replace this parenthesis with the @ sign) or visit