Damp Survey on Historic Bushy House Conservatory
The Problem
The aim of the investigation was to identify damp and timber decay problems or relevant building defects and to give recommendations on any remedial works required to correct such problems and prevent damp or decay problems in the future using environmental means.
The Solution
The investigation revealed significant timber decay, structural in most cases, particularly to the sections around the eaves and upper glazed frieze. This included timber decay to rafters, top and bottom rails of the glazed lights, the wall plates, and to the main support posts. Downpipes had been incorporated into the external columns and were found to be blocked with debris, with biological growth noted to the south, east, and west gutters leading to chronic overcharging of the roof drainage system and most likely a direct cause of the timber decay in the building. Rafter capping pieces over rooflight junctions were also found to be poorly detailed allowing significant moisture penetration and subsequent decay.
Significant remedial intervention was required in order to rectify the decayed timbers, the overcharging gutters, and the poorly designed drip detail at the joins of the rooflights. All decayed timbers were identified on marked-up CAD drawings produced by H+R from measurements taken at the time of survey, along with annotated photographs and a detailed table. Recommendations for suitable remedial repair techniques and timber species to use were provided along with advice for access restrictions prior to commencement of works.