Independent damp surveys in Croydon
Croydon is mostly interwar, and that changes the diagnosis completely. A 1930s semi has a cavity wall, a proper slate or bitumen damp proof course and a suspended timber floor over a ventilated void. Damp in a house like that is almost never rising, and treating it as though it were is how people end up paying for injection they did not need.
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Croydon housing, and what it does when it gets wet
The classic Croydon house is a bay fronted semi from the twenties or thirties, cavity walled, with airbricks at low level feeding a void under a suspended timber ground floor. Those two features do most of the work in keeping the house dry, and both are routinely defeated. Airbricks get rendered over, buried by a raised patio, or blocked by a new conservatory. Cavities get filled with retrofit insulation that slumps or bridges. Both produce damp at low level on an internal wall face, which looks exactly like rising damp and is not.
Ground levels are the other recurring theme. Sixty or seventy years of successive driveways, patios and block paving have raised the external ground on a great many of these houses above the damp proof course. Once the ground is above the DPC the wall is bridged and the course is irrelevant, however good it is. The fix is a spade and a drainage channel, not a chemical.
The town centre brings a different stock again: post-war blocks, sixties towers and a significant number of recent office to residential conversions. Those conversions were often done under permitted development with limited scope for changing the building envelope, and single aspect flats with mechanical ventilation and large areas of glazing produce persistent condensation that is a design outcome rather than a resident's doing.
What we are usually called out to in Croydon
- Damp at low level on a 1930s semi, caused by ground level bridging the damp proof course rather than by rising damp
- Blocked or buried airbricks starving the underfloor void, leading to musty ground floors and timber decay
- Retrofit cavity wall insulation that has slumped or bridged, showing as damp patches on the exposed elevation
- Condensation in an office to residential conversion where the ventilation cannot cope with the layout
- Chimney breast staining after a stack was capped without ventilation, in a house full of open fireplaces
- Pre purchase surveys on interwar stock where a meter reading has triggered a damp and timber referral
Which kind of damp is it?
In a London building the same stain can have four or five different causes, and in Croydon we regularly find two at once. Water rising from the ground through a wall with no working course. Rain entering through a parapet, a gutter, a cracked render or a window head. Moisture from the air condensing on a cold wall. Water from a pipe, a bath seal or a flat upstairs. Each needs a different repair and, in a shared building, often a different person to pay for it.
Our readings are taken to separate them: at depth as well as at the surface, at heights up the wall, on either side of the damp, and alongside humidity and surface temperatures. The pattern, not a single number, is what the diagnosis rests on.
The inspection, around Croydon and across Croydon
- Every wall showing damp, and the walls either side of it for comparison
- Rainwater goods and roof junctions from the ground and from windows, and closer where access is safe
- Basement and lower ground floors for water table, drainage and bridging at the lightwell
- Condensation risk measured with temperature and humidity readings
- Visible timber for decay and beetle, with moisture content recorded
- Anything that would need opening up, identified and agreed with you rather than done unannounced
The report
Written within 24 hours of the visit, and structured for the people who will act on it in Croydon: you, your solicitor, a freeholder, a contractor.
- A summary of the cause and urgency on the first page
- Photographs and readings, located on the building
- Who is likely responsible for each defect, where it sits outside your demise
- Remedial recommendations as a specification for contractors to price
- An indication of what that work should reasonably cost
- What does not need doing, including any treatment already quoted
How a survey is arranged
- Tell us the postcode, the property type and what has been noticed.
- We confirm the fee and the time. It does not change on the day.
- On site, outside first, then inside, with findings explained before we leave.
- The report arrives within a day, ready to forward to a solicitor, agent or freeholder.
We do not sell damp proofing, tanking, ventilation units or timber treatment. In Croydon, as everywhere in London, that independence is what makes the report useful to a buyer negotiating a price, a tenant raising a disrepair issue, or an owner deciding whether a quote is justified. Quoted for damp proofing already? Read damp proofing in Croydon: survey first.
Leaseholders, landlords and buyers in Croydon
Leaseholders in Croydon often discover that the cause of their damp sits in a part of the building they do not own. Our report says where the water is coming from and which element of the building it passes through, which is the evidence a freeholder or managing agent needs under the lease. For landlords, damp and mould are hazards under the Housing Health and Safety Rating System, and social landlords in England now work to the fixed timescales of Awaab's Law. Our guide to Awaab's Law explains what that means.
By town
Purley and Coulsdon
Interwar and post war houses on the slopes of the North Downs, many on sloping plots with retaining walls and steps. Garden run off and retained ground at the uphill wall are the usual causes of damp, along with paved drives.
Thornton Heath and South Norwood
Victorian and Edwardian terraces mixed with interwar streets. Rear additions, concreted yards and bays recur, and conversions bring shared responsibility for roofs and drains.
Addiscombe and Shirley
Interwar semis and later housing. Drives bridging the course, blocked airbricks under suspended floors and mould in bedrooms make up most surveys.
Where we cover
We cover the borough and the surrounding area, from Croydon town centre out to the Surrey boundary.
- Croydon
- South Croydon
- Thornton Heath
- Purley
- Coulsdon
- Addiscombe
- Norbury
- Selsdon
- South Norwood
Postcode districts
- CR0
- CR2
- CR5
- CR7
- CR8
- SE25
What customers say about us
Really happy with the damp survey by ATI. Tom was friendly, professional and took the time to explain everything clearly. We’d been dealing with the issue for over a year, and Tom managed to find the root cause, which was such a relief. Really appreciate his help and would definitely recommend him.
Nala Nala, on Google
Just want to say a huge thank you to Tom at ATI, from the initial survey to continued support in resolving a damp issue we have in our recently purchased property. The survey was prompt, detailed and had a clear solution on what our next steps are. During such a stressful time Tom has kept our minds at ease through this whole process, he really does go the extra mile and we couldn’t thank him enough!
Sanjay H, on Google
So If anyone else is having issues like ourselves don’t hesitate to get in contact with Tom he will certainly look after you.
Croydon questions
Can a 1930s house get rising damp?
It is possible but uncommon, because houses of that age were built with a physical damp proof course that generally still works. What is far more common in Croydon is that the course has been bridged: the drive, patio or garden has been built up above it over the decades, so water crosses the barrier rather than being stopped by it. The symptoms are identical. The remedies are not, and one of them costs a great deal more than the other.
We have had cavity wall insulation. Could that be the cause?
It can be, and it is worth checking rather than assuming. Retrofit cavity fill can slump over time and leave the top of the wall uninsulated, or bridge the cavity and carry water from the outer leaf to the inner one. The signature is damp patches on the most weather exposed elevation, often at first floor level, appearing after driving rain rather than continuously. We inspect for it directly rather than inferring it, and the report says what we found.
Our Croydon semi smells musty under the floor. What causes that?
Usually a suspended timber floor with blocked airbricks, often behind a later path or extension. Reopening and adding ventilation is the main repair, with any decayed timber replaced.
We are buying in Purley and the house is on a slope. What should we check?
Retaining walls, drainage on the uphill side and any rooms below ground level. The survey covers these and the report says what they need.
Do you survey flats above shops in central Croydon?
Yes. Damp in flats above shops often comes from parapets, flat roofs and shared drainage, and the report identifies the source and likely responsibility.
Will you try to sell me damp proofing in Croydon?
No. We carry out no remedial work, so there is nothing to sell after the survey. The report states the cause, the work that would actually fix it and an outline of what that work should reasonably cost, so you can get like for like quotes from contractors of your choice, or put it to a seller, landlord or freeholder.
Nearby
Book a damp survey in Croydon
We survey and report only, with no treatment to sell, so what the report says is the whole of our interest. Same day response to every enquiry, and a written report with photographs within 24 hours of the visit.
Book a survey or call 020 3355 4944