CLIENT BRIEF
RTP Surveyors were instructed to investigate ongoing water ingress affecting the ceiling of a wraparound extension to a C19th two-storey detached dwelling in Perranporth. The extension had previously been recovered in GRP with associated external rendering works undertaken at first floor level. Despite these interventions, water ingress persisted, requiring further independent investigation by RTP Surveyors.

KEY CONSIDERATIONS
A detailed inspection was undertaken to identify the source of water ingress and assess the condition of the roof and associated structural elements.

The investigation identified extensive deterioration of the reinforced bitumen sarking membrane, which had degraded significantly and had rotted back from the gutter line into the roof void. The eaves board was found to have been overboarded, with the original timber beneath exhibiting advanced decay.

The concrete interlocking roof tiles were also approaching the end of their serviceable life, with elevated levels of porosity observed.

In addition, the roof structure showed evidence of retrospective strengthening works, including ad hoc strutting, likely introduced to accommodate increased loading from heavier concrete tiles replacing the original, lighter natural slate covering.

The combination of these factors indicated a progressive failure of both roof covering and supporting elements, contributing to continued water ingress despite previous repair attempts.

OUTCOME
The investigation identified multiple contributory defects across the roof covering, supporting structure, and eaves detailing, confirming that prior remedial works had not addressed the underlying causes of water ingress.

The findings provided a clear technical basis for a comprehensive roof refurbishment strategy, including consideration of structural capacity, appropriate replacement materials, and full renewal of degraded membrane and timber elements.