The property
A period building in Crystal Palace divided into flats. The area inspected was the ground-floor communal hallway, directly below the kitchen of a flat above. Its ceiling was traditional lath and plaster, with a later plasterboard ceiling fixed beneath it, and a decorative cornice around the edge.
The client's concern
Leaking pipework in the flat above had reportedly let water into the ceiling for about a year. Large parts of the hallway ceiling had come down, and the building's owner needed to know whether the floor structure had been affected and what repair was needed.
What we saw
Much of the original lath and plaster, and the later ceiling below it, had collapsed, leaving the laths and parts of the timber joists exposed. There was extensive staining and mould growth, and the remaining plaster had lost its key to the laths. No active leak was seen on the day.
How we investigated
A Specific Structural Inspection of the hallway ceiling and the floor structure above it, from below. We examined the exposed laths and joists, took moisture readings and recorded the condition of the remaining plaster. The flat above was not available to inspect, so the pipework and the source of the leak could not be checked, and this was not a specialist timber decay survey.
What we found
The failure was of the ceiling, caused by prolonged water from above, rather than of the primary structure. The exposed joists appeared dry, with no obvious severe distortion or splitting. The remaining lath and plaster, however, was unstable and at risk of further collapse, and the condition of concealed timber, especially the joist ends at their bearings, where decay usually starts, could not be confirmed.
What we recommended
Strip out the whole lath and plaster ceiling rather than patching it, with the hallway protected and cordoned off while the work is done. Inspect the exposed joists, especially their ends, and have any decayed or weakened timber assessed by a timber specialist and repaired or replaced. Confirm that the leak has been permanently fixed and let the structure dry out. Then build a new plastered ceiling and make good the cornice to match.
Related services
This was a Specific Structural Inspection (SSI). Read more about our structural inspections and our work in Crystal Palace, or see more case studies.
