Opinions on the cause of this mould/damp wall? (pics of both sides provided)

smpNWI

This wall in a previously tenanted kitchen was not blocked by furniture - just one of those trolleys you keep groceries in.

It's very mouldy, and the black mould has spread to other areas of the house (where it seems due to condensation but there's mould in the air so it has caught on).

Through this wall, on the side, there is another wall that is obviously wet and mouldy – see the picture of the wall next to the door. Here, it’s higher up and more wet than mouldy.

I've posted also pictures of the exterior of the black mould wall - where you can see some green growth in the same place approximately, indicating the bricks are damp (?)

What could be causing this?

It has been suggested that 'the DPC has collapsed' but this was suggested by DPC sales people, so we're not convinced. Also obviously there's been a chemical DPC injected as seen from the drill holes on the outside (no info on this - was done by a previous owner).

As you can see there are two water pipes heading up next to the mould on the inside.

On the outside there is a drain, soil stack, gutter pipe.

We haven't been able to inspect under the floor so far but are planning to.

Any thoughts?

FreeBear

smpNWI said: It has been suggested that 'the DPC has collapsed' but this was suggested by DPC sales people, so we're not convinced. Also obviously there's been a chemical DPC injected as seen from the drill holes on the outside (no info on this - was done by a previous owner).

As you can see there are two water pipes heading up next to the mould on the inside.

On the outside there is a drain, soil stack, gutter pipe.

"DPC has collapsed" is a new one on me... Where would it collapse in to ?

The more common one from these people is the DPC has failed - OK, maybe in one or two isolated spots, but along the whole length beggers belief. And they then go on to sell injected chemicals, invariably coupled with a waterproof render/plaster on the inside. As you can see, this has failed to address the problem !

Don't think the internal pipework is the cause of the damp, so look at the external ones..

You have a solid brick wall with a cement plinth that is hiding the original DPC (assuming the building is constructed after such things were introduced). The downpipe discharging on to the gully grate is possibly causing some splashback that is soaking in to the wall. The concrete paving probably isn't helping and could well be level with, or above the DPC - A short term fix would be to cut & dig out this concrete leaving a trench ~200mm wide and ~150mm deep. Fill with a decorative gravel, and monitor the situation for a few months. If you can get rid of any waterproof render/plaster on the inside, replastering with lime will go a long way in managing any residual damp. Also looks like the wall has been repointed with cement - That won't be helping.

The damp running down the side of the door frame is likely to be poor sealing - Pull out any loose mastic and squirt some new sealant in down the outside of the frame. That particular area will be a cold spot prone to attracting condensation. Heating the room to a decent temperature will help, as will a bit more lime plaster. Avoid using modern plastic paints, and you won't have the stuff pealing off every five minutes.

One final thing - Check the state of the gutters - If rainwater is overflowing, that will be adding to the problem. So clean out the gutters and make sure the downpipe is clear.

RedFraggle

Just to add to that....is it Victorian/Edwardian and is that part of it what was originally the outhouses? If that's the case it may only be a single brick wall. 

smpNWI

RedFraggle said:

Just to add to that....is it Victorian/Edwardian and is that part of it what was originally the outhouses? If that's the case it may only be a single brick wall. 

Late Victorian small terrace, currently the kitchen. Agree that it's probably a single brick wall.