tvrulesme

That was an old telephone cable. I was trying to show the outside edge of the internal wall. Wall is directly next to the window \ The electricial cable for that lamp ran behind the fascia board. I've removed the lamp and this is the external wall with some of the old paint removed when I was trying to investigate if I had any gaping holes in the wall. Yellow string line is the internal floor level

Brilliant, thanks a lot. Makes perfect sense doing both sides or the moisture will just be pushed to the other side of the wall. I've got a decent 300mm Masonry blade for my reciprocating saw which should make short work of the cuts. I have tonnes of old slate and reclaimed brick thank you. One of my permanent eBay searches which I act on every time there's a bargain. Will keep this post updated on progress.

@joe90 please tell me to do one if I'm asking too much. You've been more than enough help already. I like the idea of the physical DPC given the conflicting views on the effectiveness of chemical. Just so I've understood, you physically cut through the brick behind the skirting to at least the depth of the brick course (~4 inches) approx 1 foot at a time to create a slot, slide in a layer of DPC and continued to the next 1 foot? Just a few questions: Did you pack the slot with anything? i.e. slate? Did you have to overlap each 1 foot section of DPC? Mine's not a load bearing wall but just want to minimise settlement cracks

Just found this after I removed wallpaper.

One thing I didn't mention is that a parquet floor is slightly buckled which would indicate damp in the floor. The dryness below is what threw me off course. Thanks @joe90 that makes sense

So you think it's coming from the floor, not the exterior? And then bypassing the botched damp proofing?

It's not occupied all the time, a few days a week. Ventilation is pretty decent. I did run a dehumidifier and it went away but has come back

It was hastily decorated. I'd be happy to hack stuff off to get to the bottom of it. It's a holiday home / mid life crisis renovation project.

A tiny tiny bit. It's not damp but a little bit of paint has come away at the same height.

Ha yes, sorry I meant the wall at right angles to this one, the exterior wall.

Thanks a lot @joe90. I hadn't thought of that. Do you mean inside or exterior? Outside is just painted brick. It's possible that some damp proffing happened inside. I'm not sure. It's damp. If I stick a heater under it it dries out but comes back

I've been slowly renovating an old 1800s listed building which was suffering from a lot of damp. I've managed to combat a lot of the damp in the house by installing French drains, fixing gutters, reverting to Lime plaster but there's one room which is completely throwing me and not sure how to move forward. There is a damp line running along the centre of the bedroom wall which is an internal wall running at right angles to the exterior wall. Floor plan of the house showing the damp wall And a picture of the exterior wall with the position of the internal wall It's not rising damp because it's in the middle of the wall and exterior ground levels are low. Gutters have been checked. Loft area above is dry with no leaks. Weather seems to make no difference. It's there when it's sunny and dry outside as well as when raining. Any ideas what investigation I should do next?

Thanks, but this is just regular mesh in render. Question here was about pinning. Saw this on another forum which seems to suggest it's a mechanical thing if vibration is a concern but can't see this clarified anywhere

Thank you. So pinning literally is when they press it in to the 1st layer? Not a mechanical fixing?

Apologies in advance for the dumb question. I'm getting a wall rendered over existing and one of the people quoting suggested pinning render mesh to the existing render. Stupidly, I forgot to ask him what this meant so now I'm curious. What pins are used and how are they applied?