CASE STUDY

Resolving concealed structural constraints to deliver a compliant warm roof

London, UK

Evelyn Mansions is a substantial Victorian residential building located adjacent to Victoria Station. The existing roof had reached the end of its serviceable life and was causing water ingress across multiple apartments.

The project required a long‑term waterproofing solution capable of meeting modern thermal performance requirements and Building Safety Regulator compliance, while respecting the architectural constraints of a heritage structure in a dense urban environment.

The challenge

During strip-out works it became clear that the existing roof construction differed from the original information available at design stage. Further investigation revealed a concealed timber superstructure above a clay pot roof with a weak screed rather than the anticipated concrete deck. This required a revised roof build-up to be developed while maintaining weather protection for the occupied building.

The approach

Langley worked with the main contractor, GTCI, and the design team to develop a revised roof build-up. The timber superstructure was removed and a cementitious board bonded directly to the clay pot substrate using Hilti shot-fired fixings, creating a suitable base for installation of the warm roof system.

The revised design was submitted to the Building Safety Regulator and approved within two weeks. Works were phased to maintain weather protection throughout the programme.

The outcome