Damp Internal Wall

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what am I brushing off of the wall and how do I know exactly where to do that?

The white paint. Wire brush in between the faces of the brick for now this should allow at least some of the moisture back out. Its not allowing any moisture to evaporate out of the brick work. You really need to get this looked at. If that really is a suspended timer floor then you might start having major issues if that damp has been there for some time you might find the ends of the timber joists have started to rot. Do you have any way to access under the floor and check?
 
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thanks I will look at this soon.

I don't have any way to look under the floor except taking the skirting board off, floorboards off etc

wire brush - do I need to go back to the cement/mortar?

I guess the paint will flake off.
 
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thanks I will look at this soon.

I don't have any way to look under the floor except taking the skirting board off, floorboards off etc

wire brush - do I need to go back to the cement/mortar?

I guess the paint will flake off.

have a look at it - does the wall feel wet after its stopped raining for a few hours? is there actual water behind the paint? is the paint starting to bubble up because the water behind it cant escape? You might have an issue that its not just the paint that is causing the issue, looks like some of that wall has been repointed. If the house is old and they have used a cement mortar instead of an lime mortar that will also trap the moisture in the brick work.

Are you 100% sure you dont have a water leak somewhere in the house? Next time you go out turn off all the taps in house so nothing can use water. Check the meter and see what the numbers are, then when you return say 3 hours later check them again, this should tell you if you potentially have a hidden leak somewhere in the house.
 
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have a look at it - does the wall feel wet after its stopped raining for a few hours? is there actual water behind the paint? is the paint starting to bubble up because the water behind it cant escape? You might have an issue that its not just the paint that is causing the issue, looks like some of that wall has been repointed. If the house is old and they have used a cement mortar instead of an lime mortar that will also trap the moisture in the brick work.

Are you 100% sure you dont have a water leak somewhere in the house? Next time you go out turn off all the taps in house so nothing can use water. Check the meter and see what the numbers are, then when you return say 3 hours later check them again, this should tell you if you potentially have a hidden leak somewhere in the house.


I doubt it is a leak because the internal wall gets worse when it rains more
so it's got to be the rain water

it was okay in the summertime, unless a magical leak has emerged somewhere.

the only water pipe we got is the mains water but it is far out from the wall
 
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That looks like a solid wall to me, see how the bricks are laid. If they have recently installed that air brick, it should be lower than the floor or it is not going to be doing anything.

Dampness caused by rain is a problem I have had before, with a solid brick wall on an 1890's house. I had the roof checked and corners and exterior wall re pointed, as was sure it had to be coming down inside the wall where the lime mortar may have crumbled.

Never got to the bottom of it unfortunately. Just one of those things with an old house. I'd just get it re boarded with waterproof stuff.
 
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thanks all, the weather is picking up here from the weekend so I will try some of the basic suggestions. It definitely has got worse over the last year.

I'm also in touch with the person who did the external wall damp injections just to get their input.
 
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Damp proof injections have a bad reputation. Old houses need to breathe. I would definitely be getting them back out if I were you to show them the damp and that the injections have not helped. These companies need to know they are taking good money from people for a solution which very rarely works.
 
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Ok the plan this weekend according to this thread is:

- Clean the gutters above
- Wipe off of the blistering paint with a brush.
- Clean inside the air brick


then I will leave it like this for now and hope to see a difference before implementing the potential soakaway!

should I also remove the paint on the inside wall to let everything breathe properly?
 
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Removing the paint from the inside wall won’t help a huge amount. You’d be better off cutting the plaster board out. It’s not a big area and will be easy to make good.
You would need to leave the board off for a good few weeks (more like months really).

I would say also that creating a French drain may not solve the problem. If the falls of the concrete outside are ok then it won’t make a huge difference - certainly won’t solve the problem and it will be more expensive than other simpler solutions that will have more effect.
 
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It will yes but giving the bricks a chance to release any retained moisture will be quicker with the board removed than leaving it covered.
 
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You could try aiding the drying process with the plaster board removed and see what happens to the wall when it rains.

We still don't know if its a solid wall.
 
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It's 100% a solid wall. Several others have stated this above. Rows of stretchers with the occasional header = solid wall.

The chemical "DPC" is probably the problem. Find your actual DPC, this should be 150mm above the ground level as a minimum and, at that age, is likely slate. I cannot see it in your photos as the paint is hiding everything. A property of that age, with a solid wall, needs to breathe. The chemicals plus the paint are likely sealing the wall and forcing the moisture out the other side i.e. internal.

Chemical paint stripper and wire brush + elbow grease to get the paint off. Let the place breathe again and, unless there is a latent defect somewhere else, your property should dry itself out.

If the chemical cowboys inserted that airbrick, check it actually is below floor level (although you wouldn't really want it any lower than it is). The ground level is likely higher than the original construction level and this is often a problem with bridging the physical DPC.
 
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Ok thanks

- gutters are fine
- paint does not easily come off with a wirebrush

there is conflicting advice on this forum about using a chemical remover to get the paint off

despite that if i did get the paint off
Its going to look rubbish
Whats the long term plan? Paint over it again?
 
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Leave it to dry out. This will take a long time especially with how wet it has been. The mortar may well have been repointed with cement. Likely it should have been a lime mortar mix which allows the wall to breathe. This is a common fault where people don't know what they're doing and just slap cement in which effectively seals the walls. You often see it where the bricks are blowing which is caused by the fact the water is coming through the bricks, rather than the mortar, and frost action blows them apart over time.

As above, find the physical DPC if you can...and ascertain if this is more or less than 150mm above the ground...
 
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ok took some point off today with a filing knife
but absolutely no sign of the DPC or something of that sort

I am Fairly certain that air brick is below the suspended floor and it was there originally prob from the 30's
except I replaced the air brick with a newer one, rather than the cast iron one from before
 
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yes the air brick should be below the floor to vent it and it would have been there originally.

DPC should be around 3 bricks from ground level. But, of course, the level might not be the same as it was originally...

Ignoring the rising damp stuff but see a picture here of a slate DPC (that apparently was bridged) - it's one brick up which is 75mm so half what it should be...

https://www.retrofitprojects.co.uk/damp-proofing-specialist-replastering-york/
 
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