Mystery damp patches...

[sedm]

Hello,
Hopefully this is the right forum for my dilemma.

I recently moved into a 1900s end of terrace ground floor flat which had damp problems. We had a new DPC injected, replastered and also fixed a few things like installing vents in closed up fireplaces.

However, a few small damp patches have started emerging again in the front room. The new paint is a bit bubbly around them and they are brownish in colour. They seem to be gathering around the edges of where the new plaster meets the old plaster.

The wall where they are appearing has a working gas fireplace in it that we use quite a lot.

Also - they are on an external wall which is next to an elderly neighbour. The wall is originally brick but it has been entirely covered with a strange sort of material - it looks like metal but has a white surface. There is also a raised flower bed against the wall. I know this is likely to be a problem - but the elderly man has not lived in the house since I've been there, and I've been on to the council but they keep ignoring me. I'm going to persist of course.

If anyone can give me any guidance as to what the problem could be... and what I can do about it... I would be very grateful! Thanks

 

[sedm]

I've posted some pictures below... if anyone has any advice that would be brilliant!!

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• sedm
• 19 Mar 2013
• 1

This is the outside wall with neighbours raised flower bed (PS - does anyone have any idea what the white coating is on top of brickwork?)

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• sedm
• 19 Mar 2013
• 1

Bubbling paint on wall...

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• sedm
• 19 Mar 2013
• 1

Sideways pic... but this is the damp above the fireplace

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• sedm
• 19 Mar 2013
• 1

Another sidesways pic but this gives an idea of the room - damp patches seem to be where old plaster join is

(Sorry for my lack of technical prowess!!!)

 

[^woody^]

The pictures aren't that good, but in any case the water is coming across the wall - either due to defective bricks, pointing, or that material holding water behind it.

You need to determine wha is wrong externally and sort that out. If it's not obvious to you, then someone experienced needs to have a look

 

[sedm]

Thanks for your reply, I really appreciate it.

What kind of tradesman do you think I should get to look at it? I have a guarantee with the damp company I previously used but I'm wary of going back to them because I wasn't impressed with the work they did and they just seemed to recommend a new DPC for everything.

The problem is I can't see the bricks on the external wall because the entire side of my house is covered with the white material

Also - I have had the chimney swept & he said it's old and dirty but it isn't blocked. We have also had the gas fire on quite a lot recently, not sure if that could be causing condensation...

 

[^woody^]

The problem with damp inspections is that unless you get a good qualified independent survey from an experienced person, then you are left with people who may have a vested interest in getting any work they "recommend", or just a partly uninformed opinion

That is not to say that tradesmen or damp company reps wont be able to diagnose, but just be wary. You could ask general builders to have a look, or damp company reps, but ask three or four different companies and see what they say. Quotes should be free.

If the cause is the neighbour's thing he has put on the wall, then that will need to be dealt with. The neighbour is not permitted to fix stuff to any wall that belongs to you

Only suspect the chimney if the damp stains are where the line of the flue would be

 

[sedm]

Thanks, that's really helpful.

Where would the line of the chimney flue be?

The patches seem to follow the join of where the old plaster meets the new plaster that the DPC firm put in. Presumably it's because this new plaster is damp-proof, so the damp is gathering above it?