Strange damp issue

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Hi there - I’m hoping for some advice on how to fix some weird damp patches in my Victorian terrace.

they’re mid wall- both on external walls and near windows.

the walls dont feel damp but are cracking, salting, rusting (the beading on the one window). It’s been replastered once and is coming back so that made no difference.

I’ve included pictures. If anyone has any experience or advice regarding how to fix this problem I would really appreciate it. I’m totally stuck what to do to sort it.

many thanks!

Following as I have the same issue.

Could you add some pictures of the outside of the walls please? Include a long view from the guttering down to the floor and close ups of the outside wall which matches where the damp is on the inside and any pipes on the walls.

I was buying a house witj this issue, the survey said that if there are salts in the wall they will continue to draw moisture in.

What's going on on the other side of the wall?

Here are some pics of the outside of the downstairs window damp - we did have the guttering checked a few years back and they said no problems. There are no pipes in this area.

These are pics of the outside of the upstairs patch - again no pipes to my knowledge (radiators on other side of the room and the water pipes to the old kitchen that would run below the floorboard below have been capped off.

Are all the seals around windows ok, ie not coming way, broken down?

We recently had a new roof (had a number of leaks). Roofers kindly cleaned the cladding on our dormer with a hose pipe and water came pouring into kitchen - turns out some of the sealant high up was starting to come away.

One other thing I'd check, do you have pipework that runs under the floorboards in those areas? If so, worth checking them - if there's been a constant leak for a while could be radiating into walls now.

Efflorescence by the looks of it.
www.permagard.co.uk/advice/how-to-stop-salt-coming-out-of-the-wall

@Sunnyside4
Ill check the window seals - thanks!
I just can’t see how it can be a pipe as the patch is in the middle of a wall nothing above or below.
the one under the upstairs window spreads sideways but there’s no problem in the room beneath.

We had a tiny gap in the window seal which you'd never have seen with the naked eye. I'd get the windows checked

Window seals is a good shout. I wonder about bodged render repairs....it looks a bit ropey and like it's been patched up and the covered over with some kind coating. The window sill on the back room looks ropey, is it wood? We had to have rotten wood sills replaced on our victorian terrace.

Looks like the results from lots of inappropriate modern materials being used in an older house that wasn't supposed to be sealed up.

@WonderingWanda the window sill upstairs is stone / slate of some kind. There’s another sill of this material in another room with no issues.

maybe I should get a window company to check the seals and sills?

@Twistytap hiw did you find it in the end?

There are companies who will come out and do damp surveys for you, they will be able to give you a good idea. One of our houses had ongoing issues and the damp was coming from multiple sources.

We got the window company out that installed the windows to look as the wall nearby was getting discoloured and damp like yours. They filled it and we've not had anymore damp spreading. I didn't watch them so I dont know how they found the gap. The weird thing was it took a couple of years to appear after installation.