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Damp Proofing Questions

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1,315 Damp Proofing questions

subfloor ventilation and damp in concrete kitchen floor

Hi, Our homebuyer report says the house we are hoping to buy has rising damp and needs additional airbrick ventilation at the rear of the property - any helpful hints on what is the best way to add ventilation?

There is also a small pool of damp under the vinyl in the kitchen in front of the sink which wasn't picked up by the surveyor or a damp-proofing survey. The area has been "concreted" over and is slightly raised from the rest of the room looks like maybe an attempt to stop the damp in the past? The base of units around the floor are wooden and are all sound.Any ideas what might be going on here and what can be done about it? Thanks for your help. Mel

Damp problem on upstairs external wall and adjoining party wall

I have a damp problem which has gradually worsened over the last six months. It's appearing in the top corner of a bedroom where the external wall meets the pary wall but has spread down the wall now. I thought it might be because the hopper was blocked on the downpipe just behind this area but we are still getting water ingress through having cleared it out. I'm now wondering if it might be the roof but there is no apparent damp tp the ceiling which I thought made it less likely? The external wall is solid brick with render but I can't see any obvious cracks in the render from ground level. Does anyone have any idea what might be causing it and possible remedies. How long would I continue to get droplets of water appearing on the inside wall for if it was down to the hopper?

Conflicting info regarding re-pointing period property

Hi there,
We live in a first floor flat in a converted period house in North London. The house was built in 1910.
Both us and our downstairs neighbour have suffered intermittent damp issues; both in the upper areas of the rooms at the back, which is mostly prominent after bouts of heavy rain, suggesting penetrating damp.
We have had a damp survey, and have scoured the internet, but we have received much conflicting info regarding how best to rectify our problems - we have been told that filling in where the pointing is missing with cement, and then using a damp proof wash on the house will suffice to prevent water coming in, which will in time dry out; however, we have also read that cement render is very bad for period properties as it traps condensation, and that we should use lime mortar, however, this seems to be a far costlier option. We have also been told that damp proofing course will possibly be required for our downstairs neighbour, however, we have also been told this is bad for the bricks and won't allow the house to breathe, causing further problems down the line. Having looked at the house, it seems that we have patches where the pointing has been replaced with cement, however this isn't where the problems are occurring.
We're unsure of the best course of action to take, so some advice will be greatly appreciated.
Many thanks,

What will need to be done to sort out damp walls?

My stone house was built in 1920s. Inside, by the front door, the wall is damp and plaster coming off. Directly upstairs, new wallpaper is developing mould. There's a drainpipe outside. It's a narrow strip of wall - is the drainpipe to blame? My house is not well-insulated and there's plenty of air circulating.

damp on chimney breast

We have what looks like salt dampness on on chimney breast. We ideally wanted to lay laminate flooring in the next week and sort the damp in a few months time so we can actually move in to the house. Would the laminate have to be pulled up for remedial works?

Is this a vertical damproofing?

Hi. I have a barn converted to house in the 1960s. Recently took radiators off walls to find severe damp behind one of them(central heating apparently hasn't been used for 3 years).
Knocking some render off wall, I discovered a vertical, bitumen painted, corrugated, fibourous, 1mm thick continuous layer that the render has been screed onto.
Can anyone identify this as a damp proofing.
The rear of the property which is built into surrounding ground (up to 1st floor level) is currently dry, but the side walls (where this suspected damp proofing was found) are damp and this material has been compromised by screw holes for radiator supports and back box for electrical socket.
The front of property also has evidence of this layer of damp proofing where a gas pipe has recently been replaced.
I guess my questions are,
1. Is this a damp proof course
2. Is it any good, or was it a 1960's fad
3. What can I do about the rear of the side walls that are damp

We were strongly advised for a rewire (in fact it is part of mortgage condition)
Which is good, because when we looked in socket it actually looked damp and backing plated and wires were rusted!!

Sealer for asphalt steps

What is the correct product to seal old asphalt on path and stairs to front door of victorian terrace house? Water is permeating to cellar room underneath, so looking for a suitable sealer to paint over as a temporary measure.
Thank you both for the replies.

My view is that this is a temporary fix. The old asphalt has expanded and shrunk over a long time and has outlived its useful life and needs replacing. It is full of cracks which I believe are most (but not all) of the cause of the water ingress to the small cellar below the path.

As a temporary measure I am looking for something to seal the asphalt whilst trying to retain a similar colour so that it doesn't look out of place with the rest of the street (i.e. blue grey of asphalt rather than a dark black). At a later stage I will have to get asphalt redone properly.

Any suggestions of branded products would be much appreciated.

Thank you

What is causing the damp spots?

We have recently moved into a new house and re-plastered the bedroom. We have noticed that after the heavy rain yesterday a few wet looking area have appeared at the top of the wall. It is an external wall, part of an upstairs extension. We also get a lot of condensation on the windows, what could be the cause? could they be related?

Patchy Damp Spots


Since moving into our end of terrace Victorian House 2 years ago we have been trying to identify the root cause of patch damp spots.

They mainly reside in our dining room within the alcoves several inches above the skirting with some small patches on the chimney breast.

We also have some very minor spots in the Lounge and the 2 bedrooms above the lounge and dining room.

We have had many builders round and they aren’t sure.

I’m pretty sure it’s not the roof as we have had that checked also.

Could pointing be the issue? I’ve seen worse but it’s not brilliant and we appear to have some suspect bricks.

Should we also invest in some sort of damp proofing?


Injection damp proofing, has it actually been done?


I have recently had a local company out to carry out some damp proofing work on some internal brick walls. They are at the stage now where they say so far they have completed:

- Taken off the plaster to around 1m high.
- Drilled the two lowest courses of mortar approx every 100mm.
- Applied the injection damp proofing.
- Re plastered The Walls

All they need to do is re attach the skirting boards.

At this point i have decided to have a look at the work and from what i can tell, no injection has taken place, All of the holes which are still visible are empty and i can easily stick a screwdriver in them to approx 3inch deep, scrape away a bit and brick dust comes out.

Common sense and a quick images search on google suggests they should be full with something resembling a silicone seal.

Some images here:http://bit.ly/1TSLjxb

Any advice appreciated.

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