Daniel Sandell identified that whilst the roof was at the end of its natural life, fortunately, it was suitable for an overlay system rather than a costly entire roof strip and replacement. To improve the drainage, the refurbished roof system would also include a tapered warm roof design around the sump outlets.
The StressPly Flex built-up membrane system (BBA-certified) was specified to overlay the 930 sqm roof to deliver a thermally efficient, fully waterproof warm roof refurbishment. StressPly Flex is a high-strength torch-on bituminous waterproofing system designed with superior tensile and tear strength for optimum waterproofing performance.
The Approved Contractor, Richard Soan Roofing Services, got to work preparing the roof by removing the hazardous existing coping stones and debris and plywood board capping the parapets. Torch Flex, a high-performance VCL, was installed, and an additional 90mm flat board and drainers were added to bring the total u-value to 0.18 W/m2K.
A Torch Flex Ultra Vent underlayment sheet was installed before finishing with the StressPly Flex 4.2mm bituminous slate finished cap sheet. The parapet walls were encapsulated with the StressPly Flex system and completed with a GRP Trim.
To complete the works, the aged and underperforming rooflights were removed and replaced for improved thermal efficiency, increasing the volume of natural sunlight for the classrooms below.