Proud member of the Federation of Damp
Rising Damp in a Bay Window and Bedroom Damp on Tolworth Road, KT6
A house on Tolworth Road had damp in two rooms: the living room bay window and a front bedroom. The survey found rising damp in one and penetrating damp in the other, with poor ventilation adding to both.
Project at a Glance
The Brief
The owners wanted to understand why damp was showing on the road facing walls downstairs and upstairs.
The Survey
In the living room bay window, rising damp was found on the road facing wall up to sill height. Room readings showed 22.6 C, 57.5 percent humidity and a dew point of 13.8 C, which the surveyor flagged as high due to limited ventilation. A built in unit had also developed mould from stored items and still air.
In the front bedroom, penetrating damp ran along the road facing wall, caused by cracks in the external render. Humidity there was 59.1 percent with a dew point of 15.2 C.
The Solution
The report set out the treatment and the preparation needed:
- Carefully remove the decorative detail on the curved bay wall so the wall could be treated.
- Have the built in units moved by others before work started.
- Treat the affected walls as specified in the report and repair the external render cracks.
- Improve ventilation, including vents to built in unit doors.
The Work
Advanced Damp completed the work over three days.
The Result
The owners came away knowing which damp was which and why the air inside mattered too. See our page on damp proofing in Surbiton for more work in this area.
Frequently Asked Questions
Can rising damp and penetrating damp happen in the same house?
Yes. It is common for one wall to have rising damp and another to have rain getting in through cracked render.
Why does high humidity matter?
When humidity and dew point are high, moisture condenses on cool surfaces, adding to damp and mould.
Why is there mould inside my built in wardrobe?
Stored items and closed doors stop air moving, so moisture builds up. Clearing some items or adding vents helps.
Damp in a bay window?
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 Lionel Sewell (FODCS) at Advanced Damp. Project completed in Tolworth, KT6.
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.
