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1,146 Damp Proofing questions

Are air bricks required below wooden flooring?

I have discovered the joists under the wooden floorboards in my 1880's house have wet rot and historical woodworm infestation. We pulled up the boards and to my understanding, there should be air bricks on the outside, above the floor level, and then air bricks on the inside, below the floor level, to aid ventilation. There are no air bricks on the inside (just on the outside), the walls are narrow cavities - what is the purpose of having air bricks just on the outside and not flowing inside the house? Should their be air bricks to aid ventilation under the floors? Some of the timber below the main joists are touching the soil, hence probably a contribution also to the wet rot problem, which to my understanding needs to be dug deeper and the joists replaced with treated timber, is this correct?
Thanks in advance for any advice.

Basement/ground floor flat has no damp-proofing

We live in a maisonnette flat - the lower ground (basement) floor is an open plan kitchen/living room/dining room, and the ground floor has a living room, bedroom, bathroom and hallway. We have the bottom two floors of a 4-story detached stone house (not sure of the age - early 1900s I think).

My husband has lived in the flat for 10 years. In the past couple of years we have had an increasing problem with damp, throughout the whole flat but particularly on the bottom floor. We got someone round to look at it recently, and it transpired that there is no damp-proofing or tanking in the flat. This fact was not revealed when my husband had the Homebuyers survey done before he bought the flat.

We have been informed that to deal with the damp problem, we'd need to spend around £17,000 on the tanking/damp-proof course... money which we simply do not have.

We were planning to sell our flat and move on in the next couple of years; our fear now, obviously, is that we will never be able to sell the flat without getting the damp proof course put in.

So my questions are: a) is there any easier/cheaper way of dealing with the damp; b) if we don't get the damp-proof course put in, is there any way on earth anyone would still buy our flat (I realise we'd have to reduce the price to reflect the lack of damp-proofing)?!

It's quite a dire situation we find ourselves in, so any advice greatly appreciated!!

Damp Proof Course under ground level for a couple of years

Looking to buy a property where part of the damp proof course is under ground level by a few centimetres. Chemical damp proofing was done a couple of years ago and it looks like the current owners have simply put paving in that sits a bit high, has gone over the damp course and blocked off the air bricks.

Surveyor isn't overly concerned as the property is 1900 terrace and they suffer a bit from damp (apparently). It also looks like the work is a couple of years old that may have caused this.

Immediate thought is to reestablish the gap by bringing the paving back and ensuring there is adequate space for the bricks to breathe, then let the lot dry out.

Any thoughts on additional work that I should be considering?

Damp proof, replastering and rendering done 4 years ago: now cracks and inside wall black with mould.


4 years ago the previous owners of our 1850's end terrace had work done to the house to erradicate a damp problem. Now 4 years on there are large black circles under the wallpaper coming through. I have looked at the outside of the house and noticed that there are large cracks directly outside where the black mould has appeared. Some builders have had a look for me and said that the rendoring has not been finished off properly, one said it has been done in 2 halves causing the cracks and another has said that because the rendering has been done up to the top of the bedroom ceiling and not up to where the roof is the rain is hitting the wall and sitting on this ridge where the rendering has gone up to causing the cracks, the builder said the company who did it should have tiled this ridge so the rain would flow back down instead of sitting there.

I have spoken to the company who say they have no guarantee and it is our problem but if this is job that has been done to poor standards I will get others involved. We have only been in the house 10 months and this was not picked up by the surveyor. Would anyone be able to give some helpful advice please?

Thank you.

Kitchen plaster flaking / white fluffy powder in areas


Our kitchen has a small extension on the end of it and we have some issues with the plaster work on one wall only. The wall has a washing machine and dishwasher along it (if relevant!).

The plaster near the dishwasher is mostly fine but along the corner edging the plaster has eroded slightly exposing the metal corner bit (if that makes sense!) which has gone slightly rusty. This has happened from about a metre off the ground and extends for perhaps 50cms on and off along the corner edging.

Rather than the kitchen and extension being one large room, the extension is separated from the main kitchen as a part wall (running floor to ceiling) extends into the space from the outside wall. It is on this part wall that juts out and separates the extension/kitchen that the plaster has bubbled and there is a white fluffy powder present. The area affected is perhaps 30cm by 15cm and again seems to affect mostly the corner areas of the plaster.

I have pulled the washing machine out and the plaster behind it seems in good condition and dry. The wooden skirting is also unaffected.

Please can anyone suggest what I can do to remedy the problem? It just seems strange that only certain areas are affected, so I'm wondering if its a condensation problem rather than penetrating damp which requires a damp proof course.

Thank you so much in advance - any help/advice is much appreciated.


i had damp in my kids bedrooms out side walls,my housing came round and put up stud walls,but i can smell the mold and there is spoills on the new walls,what should i do?

my houseing said its condansation but why did thay put up stud walls?

We keep getting a musty damp smell, but not all the time.

The damp must smell comes and goes, we are in a single story old property, that was done up in the 1980, it had a garage changed to a bedroom. it had odd shower rooms in the bedrooms when we moved in, we had them taken out quite a few years ago. We have two pipes on the outside wall, I think for rain run off. We used to blame the smell on the old carpet they left, but it has been taken out. I'm not sure if it comes from the drains out side or the pipe work to the bathroom.
We seem to have the art of finding people to rip us off and not do the job, so we keep leaving this, but it really needs doing. Do we get a builder out, or a damp proofing company. Not sure what to do really.

I have mould under my windows,where is it coming from

My window sills have water,possibly from the condensation,but under neath I am getting about 1metre area of mould.Is it from the windows.

How to fix a damp wall

The front room wall, that is also the outside wall, has had damp appearing for the last year, ever since I had some boxes lent up against it. Now the wall has gone bobbly in places and yellowy, and is cold to the touch and clammy. There are cracks appearing too, but all just coming up from the bottom up to around 40 cm from skirting board.

Whats the best thing for sorting it out? Painting Anti damp stuff onto it, or will that cause it to spread further up the wall.? Or do I need more specialist work done on it?

Can someone tell me about air bricks

I have a damp problem under the floorboards in my dinning room - i think i have resolved the problem cauased by a leaking drain - but it still seems very damp down there. I just wondered what the ideal amount of airbricks are per property - there was once a chimney in the room, which has been removed - but the brickwork remains below the floorboards. Could that make a difference?

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