Damp Victorian mid terrace - send help!

[NLondonterrace]

We bought our first property back in January, a lovely flat fronted mid terrace house in London. It had been done up by a developer, newly painted etc and looked pretty much flawless. In the 9 months since we have lived here sadly it’s become clear that they’d just painted over a lot of issues with damp. We have several patches on the ground floor, primarily on the internal party walls on either side of the house, causing the paint to flake off and look a mess. They feel damp to the touch too.

We’ve been kind of ignoring these but recently noticed a really significant patch in the vicinity of the old chimney breast and thinking we probably do need to do something about all this now. I’ve read a load online about salts in old chimneys, inappropriate use of modern materials in old houses etc causing this sort of thing but not sure where to start to actually fix the problem! Advice would be hugely appreciated.

 

[RBailey]

Sadly this does look like trapped moisture and salts.
I suspect as you said it was "done up" by a developer, aka bodge it and scarper they will have used gypsum and the full range of non-breathable materials.

Firstly try to locate and fix sources of the moisture, raised ground levels, blocked water goods, damaged roof / tiles etc.. and then you may need to re-plaster / re-paint with breathable traditional materials (lime etc,)

Have a read of the Haynes "Period property manual" as a first stop then for more in-depth look at Peter Ward's "The warm dry home".

 

[Lacan07]

The soot of a chimney interacts with the lime mortar to create salts which in turn attracts moisture, as I'm sure you've read about already. It's not a huge problem and people tend to just live with it. One option would be strip the plaster off and leave it as brick if it looks decorative enough.

I can't quite tell but some of those wet patches look quite high up the wall, I would check for leaks first.

 

[NLondonterrace]

Thanks! I do like the idea of exposing the brick actually but nervous that it might not be great condition under there! I think as first port of call I'm going to get someone to take a look at the chimney and see if that's letting in any water and take it from there...