Damp in the Original Solid Brick Walls of a House on Ambler Road, Finsbury Park N4
A house on Ambler Road in Finsbury Park had damp affecting the original solid brick walls in the entrance hall, under the stairs and in the kitchen. The survey found several outside causes that needed to be dealt with as well as the walls themselves.
Project at a Glance
The Brief
The owners wanted a localised survey of damp in the older part of the house, where staining and damaged plaster were showing in the hall, under the stairs and in the kitchen.
The Survey
Readings were elevated on sections of the original 9 inch solid brick walls, with visible staining and heavily moisture affected bonding plaster. There was evidence of earlier damp proofing in the kitchen. The later cavity wall section of the kitchen extension did not show the same pattern.
Outside, the surveyor recorded several likely contributors: heavily deteriorated mortar joints around the front bay window, deteriorating timber bay windows, a garden party wall and limestone pillars in contact with the main wall, locally high ground at the rear, and a very narrow gap to the neighbouring extension that restricts airflow. A disconnected cast iron pipe linked to the neighbouring property was also noted, and a possible plumbing leak behind the kitchen boxing in was flagged to be checked before any damp work began.
The Solution
The report split the work by responsibility:
- External repairs and investigations, including repointing, the bay windows, the disconnected pipe and the concealed plumbing check.
- Remedial damp proofing by Advanced Damp to the areas marked on the floor plan, with damp affected plaster replaced.
- A drying period for the treated walls before decorating.
The Work
Advanced Damp carried out the damp proofing works on 29 and 30 August 2026.
The Result
Treating the walls without dealing with the bay pointing, the high ground and the pipework would have left water feeding back in. Solid brick terraces around Finsbury Park and Stroud Green often have the same mix of causes. See our page on damp proofing in Finsbury Park, or read more about penetrating damp.
Frequently Asked Questions
Why did the extension stay dry when the old walls were damp?
The extension has cavity walls, which separate the inside face from the outer brick. Original solid walls have no cavity, so moisture in the brickwork can reach the plaster.
Can a neighbouring property cause damp in my house?
Yes. A disconnected pipe, a party wall in contact with your wall, or a tight gap that traps moisture next door can all add to the problem.
Why check for a plumbing leak first?
A hidden leak can look like damp in the wall. Ruling it out first means the treatment is aimed at the real cause.
Damp in solid brick walls?
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 Finsbury Park, N4.
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.
