Montrave Road, Penge · Photo: Chris Whippet, CC BY-SA 2.0
Penge & Anerley, SE20
Damp, mould and ventilation in Penge and Anerley
Conversion flats, internal bathrooms and solid walls. The three things that put this postcode top of our call list, and what each of them needs.
The homes here
Big Victorian houses, now two or three homes each
Penge and Anerley filled up quickly in the second half of the nineteenth century, and a great deal of it was built as large family houses — three storeys, bay windows, deep plans. Very often they are two or three flats now.
A conversion puts kitchens and bathrooms into rooms that were never meant for either, frequently in the middle of the plan with no outside wall to put a fan through. That single fact decides the price of the job more than anything else, and we tell you which you have before we quote.
- The internal bathroom. No outside wall behind it, so the extract has to be ducted out through a ceiling to the nearest face that can take a terminal.
- Flats stacked over each other. Floors and walls are shared, so one flat’s moisture problem rarely stays in one flat.
- Letting brings the law in. A landlord’s duty to keep a home fit to live in applies today, and damp and mould is squarely inside it.
More of our mould work comes out of SE20 than anywhere else we go, and it is not bad luck. It is the housing. Penge and Anerley are dense with Victorian and Edwardian terraces, a large share of them long since divided into flats, and that division is what causes most of it.
A terraced house was built with one ventilation strategy for one household: chimneys in every room, sash windows that leaked, a scullery at the back. Split it into two or three homes and you get two or three kitchens, two or three bathrooms and two or three households breathing — served by the ventilation of one house, most of which has since been taken away.
Why conversion flats go mouldy
Five specific things, and the first one is the one that decides what a job costs.
The bathroom has no outside wall
When a house is split, the new bathroom usually goes wherever it fits — which is very often the middle of the plan, off the hallway, with no external wall behind it. That rules out the obvious job. It needs an inline fan in the ceiling void and a duct run out to the nearest outside face, which is most of a day with a ceiling open rather than a couple of hours. It is the single biggest price difference in this work and almost nobody is shown it before the quote.
Solid walls, running cold
One brick thick, no cavity. The inside face of every external wall sits below the room air temperature, so it is the first surface moisture condenses on — behind furniture, in the corners, down the window reveals. That is where the mould appears, and it is a surface temperature problem being fed by a moisture problem.
Sealed up on both counts
Chimneys capped, original windows replaced with double glazing fitted without trickle vents. Both were background ventilation and both are gone. An extract fan can only pull air out of a flat if the flat can let replacement air in — which is why fitting a bigger fan into a sealed flat frequently changes nothing at all.
One flat's moisture is not only its own
In a conversion, floors and party walls are rarely as airtight as they look. A ground-floor flat drying washing indoors is putting moisture into a structure the flat above shares. It is worth surveying the whole building where we can rather than one dwelling in it.
The moisture is ordinary, and that matters
A household of four puts something like ten to fifteen litres of water into a home every day just by living in it — showering, cooking, drying washing, breathing. That is not a lifestyle failing and it is not something to be scolded about. It is the normal quantity, and a home has to be able to get rid of it.
If you let a property here
What already applies to you, today
The Homes (Fitness for Human Habitation) Act 2018 lets a tenant take a landlord to court directly over a property that is unfit, and damp and mould is a category 1 hazard under the HHSRS. Section 11 of the Landlord and Tenant Act 1985 sits alongside it. Neither of those is coming — both are live.
Awaab's Law is a social housing duty and does not apply to the private rented sector. The Renters' Rights Act carries the power to extend it, but it is not in force for the PRS and no commencement date has been set. Anyone telling you otherwise is selling you someone else's obligation. It is worth getting ahead of; it is not something you are currently breaching.
What we give you is a survey that measures rather than blames, a fix, and a commissioning certificate with the airflow at every terminal on it — which is the document that answers a complaint, an environmental health officer or a solicitor's letter.
If you live here
Then the first thing worth saying is that it is almost certainly not your fault, whatever anyone has told you about opening a window. You can see the whole thing happen on the simulator on this site: pick a flat, watch where the moisture comes from, and watch what each of the four systems actually does about it.
Not sure where to start?
Send us a message with what you have noticed at home. We will tell you honestly whether you need a survey, a system, or neither.
Or see what it costs — unlike most in this trade, we publish our prices.
Trained on the systems we install
Certificated — and here they are
Most trade sites show you a row of logos. These are the actual certificates, held by this business. Tap either one to read it, or download the PDF.
- 12-month workmanship guarantee On top of the manufacturer’s warranty, which we register in your name. If anything we installed fails because of the way we installed it, we come back and put it right. What it covers.
- Company no. 12092552 Registered in England & Wales. Trading as Cavalli Ventilation since July 2019, and in ventilation since 2003.
- Airflow measured on every install A calibrated anemometer at the grille, recorded and handed over. The only figure that counts is the one measured in your room.