Damp in a Part Below Ground Kitchen on Brands Hill Avenue, High Wycombe HP13
A house on Brands Hill Avenue in High Wycombe had damp in a kitchen that sits partly below outside ground level, with a vaulted ceiling above.
Project at a Glance
The Brief
The owners wanted to know why the kitchen wall kept showing damp.
The Survey
The affected wall sits partly below external ground level. Concrete hardstanding and step details outside appeared to bridge the visible damp proof course, and the DPC itself was irregular, with several visible lines and changes in level.
Other contributing defects included deteriorated sealing around service penetrations, poor detailing around replacement windows, poor rainwater discharge, possible defects with the retained cast iron downpipe and local deterioration to drainage and masonry. The internal moisture profile matched moisture ingress through the wall.
The Solution
Treat the full extent of the affected wall:
- Remove the damaged finishes and carry out damp proofing up to the underside of the vaulted ceiling.
- Address the external sealing, rainwater and drainage defects alongside the internal work.
The Work
The damp proofing, electrics and associated works ran from 11 to 13 August 2026.
The Result
The whole affected wall was treated rather than a strip at the bottom, matching the extent found in the survey. See our page on damp proofing in High Wycombe.
Frequently Asked Questions
Why treat a wall up to the ceiling?
Where moisture affects the full height, as here with a vaulted ceiling, treating only the lower section would leave damp finishes above.
What does it mean when there are several DPC lines?
It usually shows past alterations. It makes assessment harder and can leave gaps where moisture gets through.
Do downpipes cause damp?
A leaking or poorly discharging downpipe can soak the base of a wall, so it is always checked.
Damp in a kitchen below ground?
Our CSSW and CSRT trained surveyors find the real cause before recommending any work. Non-invasive survey with a clear written report. No obligation.
Survey carried out by Chris Baxter at Advanced Damp. Project completed in High Wycombe, HP13.
Sam Fitzgerald is the founder of Advanced Damp and a working damp and structural waterproofing surveyor diagnosing and treating moisture problems in residential and commercial properties across London and the South East. He is FODCS certified (a Federation of Damp Certified Surveyor) and a member of the Federation of Damp. His hands-on work covers rising damp, penetrating damp, condensation, basement waterproofing to BS 8102, and thermal imaging surveys, and he has personally completed over 400 damp surveys across properties of every type and age. Everything he writes draws directly from jobs he has carried out. He does not write about treatments, products or causes he has not dealt with first-hand in the field.
