Kemper System helps protect concrete heritage

Cold-applied liquid waterproofing specialist, Kemper System, has helped to preserve a grade II listed building thanks to its Stratex warm roof and Kemperol liquid roofing systems.

Because of the unusual design of St Thomas More Church in the Sheldon area of Birmingham, architects Wood Goldstraw Yorath worked in close consultation with Kemper System to enhance the waterproofing performance by addressing leaks and U/V damage to the existing substrate, whilst also improving drainage and reducing the risk of standing water on the roof.

The structure of the building with its many glass and concrete terraces, saw Kemper System’s Stratex tapered warm roof system being specified along with their solvent-free and odourless Kemperol 2K-PUR waterproofing membrane to refurbish the church’s failing asphalt roof.

The technical team at Kemper System also devised a series of drainage channels to address the volume of standing water on the roof, whereby excess water would be caught and drained off the building.

Contractors, Alliance Technical Services Ltd, a specialist conservation company, not only worked to recover the roof with Kemper’s Stratex warm roof system, but also installed new glazing to the central ribs and high level roof windows, fitted an external downpipe and drainage, and completed concrete repairs and concrete rib replacements.

For the recovering of the roofs with the Kemper designed system, operatives removed the existing chippings on the roof ready to clean and prime the asphalt substrate, and installed a hard top tapered Kempertherm PIR insulation board. This was adhered to each terrace section in such a way to create channels behind and either side of each piece of insulation.

As primarily structural engineers, Alliance Technical Services Ltd undertook thorough product and application training at Kemper System HQ in Warrington before installing the Kemperol 2K-PUR system, to familiarise themselves with the liquid waterproofing product application.

Derek Lowe, Managing Director at Alliance Technical Services Ltd, said: “This was a particularly interesting project for us as the church required remedial works to the concrete whilst also installing an alternative waterproofing solution to ensure the graded building remained watertight. The Kemperol 2K-PUR liquid applied waterproofing system was an ideal solution to work around the complicated structure of the building with its many terraces, outlets and joints. These formally weak areas were able to be fully waterproofed in one seamless, easy application.

“We undertook excellent training at Kemper’s headquarters to ensure we were able to apply the system effectively and efficiently. Thanks to the durability of the Kemperol 2K-PUR waterproofing system, the church’s heritage has been protected and can continue to be enjoyed by its many visitors.”

Technical manager at Kemper System, Ross Smith, added: “This interesting project presented design, specification and installation challenges which were easily solved thanks to versatile qualities of the Kemperol membrane.

“The wet-on-wet, cold applied liquid was the perfect solution to ensure a quick and easy installation, yet providing the reassurance of a sound, waterproof solution for many years to come. Its odourless, solvent-free qualities meant the refurbishment works created little disruption to local residents or those using the church.”

Added to Historic England’s ‘At Risk’ register in 2015, the Roman Catholic Church of St Thomas More was designed by renowned architect, Richard Gilbert Scott – who also designed the Guildhall’s West Wing and Art Gallery – with stained glass by John Chrestien.