Cheylesmore House, Coventry | System THX

LOCATION

Cheylesmore House, Coventry

WATERPROOF SYSTEM

Project Type: System-THX PU Liquid Waterproofing

System: System-THX

Roof Type: Single Ply

BACKGROUND TO THE PROJECT/CHALLENGE

A government-owned administrative building required refurbishment works to an ageing flat roof system suffering from deterioration to the existing single ply membrane. The objective was to restore the roof’s waterproofing performance while avoiding the cost, disruption, and environmental impact associated with a full roof replacement.

Following a detailed roof condition survey, a liquid polyurethane (PU) overlay system was specified to provide a seamless, fully bonded waterproofing solution capable of extending the operational lifespan of the existing roof.

The client outlined several key project priorities:

• Maintain building operation throughout works
• Minimise disruption to staff and public access
• Avoid intrusive strip-and-replace roofing works
• Deliver a cost-effective long-term waterproofing solution
• Improve overall roof performance and weather resistance
• Reduce waste sent to landfill in line with sustainability objectives

As the building remained fully operational during the project, careful planning and phased working were essential.

PROJECT SOLUTION

System-THX PU roofing system was selected as the preferred refurbishment method due to its ability to overlay the existing membrane without requiring full removal.

The specification included:

• Full roof preparation and cleaning
• Localised repairs to defective membrane areas
• Application of specialist adhesion primer
• Reinforcement of all critical details, laps, and penetrations
• Installation of a reinforced liquid PU waterproofing system across the entire roof area

The liquid system provided a seamless finish, eliminating vulnerable joints and significantly improving long-term waterproofing performance.

SCOPE OF WORK

Surface Preparation

The existing single ply roof was thoroughly cleaned, power washed and prepared to ensure optimum adhesion. All loose materials, contaminants, and failed detailing were removed or repaired prior to coating application.

Primer & Overlay Application

Our System-THX 0130 PVC Single Ply Primer was applied across the roof before installation of the liquid polyurethane waterproofing membrane. System-THX Embedment Coat was installed at 2.0L/m² with a 225 g.s.m. glass fibre reinforcement mat. An additional coat of System-THX Protection Coat at 0.3L/m² was installed to finish the system.

Maintenance and access walkways were installed using a mineral finish cast into the liquid coating system.

Key Benefits Delivered

• Seamless waterproof roofing system installed
• Extended lifespan of existing roof structure
• Reduced disruption compared to full replacement works
• Lower overall project costs
• Improved weather and UV resistance
• Reduced waste to landfill through overlay refurbishment
• Maintained full building operation during works

The completed system now provides a durable and maintainable waterproofing solution aligned with the client’s long-term asset management strategy.

THE OUTCOME

The liquid PU overlay refurbishment provided a practical and sustainable solution for extending the service life of the government building’s existing single ply roof system. By avoiding full roof replacement, the project achieved substantial cost savings, reduced environmental impact, and minimised disruption to daily operations.

This project highlights the effectiveness of liquid-applied roofing systems in public sector refurbishment environments where operational continuity, sustainability, and long-term performance are key project drivers.

We worked with Crescent Roofing for this project.