damp from wall - my responsibility or neighbours or both?

wallofbeans

ThisIsWeird said:

wallofbeans said:

I've uploaded some photos of the issue inside. My neighbours aren't home so I can't get access to take photos of exterior wall yet, but will come back with those ASAP.
https://imgur.com/a/KAsahK5

You can upload such pics directly on to this site - see the wee 'mountain pic' icon top-middle of the 'leave a comment' box?

It'll be interesting to see the other side. The obvious damp just above floor level could be a DPC breach issue, but we'd need to see. The higher-up marks are unusual, and obviously suggest an issue further up.

Where does the rainwater gutter run for that roof?

How long ago was your extension built? I don't suppose it's shown on your LA's Planning Portal?

What's further along to the left of that radiator wall? I presume an end wall facing your garden? This will have a window or door in it? If so, could you take a couple of accurate measurements, please - one inside, one out.

Inside; from the door/window 'reveal' - ie where it steps into the wall - to the radiator wall.

Outside; from the exact same starting point as the inside - so you'll need to transfer that point outside - to the outer (neighbour) surface of that wall. 

Subtract the two to get wall thickness - just to see if it throws up any surprises. 

I know that pics can be uploaded directly here, but they always appear so big and it's neater to just add the link.

I'll take some exterior pics to give you a sense of the layout and upload in a few minutes, but just to say I have no idea when the extension was built - I couldn't find it on the planning website and I know the previous owners didn't do it and they were hear from 2009 until I bought in early 2021. The people before that were from 2001 but I suspect it was the people before that who did it in the 90s.

And yes, on the left of the picture is just the end of the building and patio doors out onto decking. 

wallofbeans

Some more pics - hope this helps give a sense of the layout:

https://imgur.com/a/X1IL0ZV

Apologies, I'm not sure what you mean by the measurements you want me to take. Can you further explain what you mean by "door/window 'reveal' - ie where it steps into the wall" as I'm not sure what "reveal" or "steps into" means...

wallofbeans

I think the wall thickness is the same on the outside and inside. The patio doors/window are right to the edge, so the outside and inside measurement are the same - I measured the outside, marked in green on photo, and it's approx 23-24cm. I hope that is what you were asking, but let me know if not. 

stuart45

wallofbeans said:

Some more pics - hope this helps give a sense of the layout:

https://imgur.com/a/X1IL0ZV

Apologies, I'm not sure what you mean by the measurements you want me to take. Can you further explain what you mean by "door/window 'reveal' - ie where it steps into the wall" as I'm not sure what "reveal" or "steps into" means...

The reveals are what you can see either side of the frame jamb. When you build a wall with a window opening, the brickwork where the frame is fixed vertical is called the window opening jamb. The timber part of the frame that's fixed to the brickwork is the frame jamb. The masonry exposed inside is the inner reveal, and the bit outside is the outer reveal.

wallofbeans

stuart45 said:

wallofbeans said:

Some more pics - hope this helps give a sense of the layout:

https://imgur.com/a/X1IL0ZV

Apologies, I'm not sure what you mean by the measurements you want me to take. Can you further explain what you mean by "door/window 'reveal' - ie where it steps into the wall" as I'm not sure what "reveal" or "steps into" means...

The reveals are what you can see either side of the frame jamb. When you build a wall with a window opening, the brickwork where the frame is fixed vertical is called the window opening jamb. The timber part of the frame that's fixed to the brickwork is the frame jamb. The masonry exposed inside is the inner reveal, and the bit outside is the outer reveal.

So these bits?

stuart45

It looks like there isn't an inner reveal on that side. It doesn't matter for measurements, as you've measured the wall's thickness as 230mm. This means it's probably a solid 9 inch wall. If there's cracks in the render, it's likely that moisture is penetrating the wall now that it's not sheltered anymore.

Grotdog

Damp... caused by excess moisture in your home.  Best solution is to manage moisture - how well ventilated is the area? Do you have constant humidity controlled extraction? Is heating always on to give gentle background heating? Constant heat stops the base of walls getting cold and dropping below dew point - which causes condensation within the wall, and all the damp symptoms. Background heat and humidity controlled extraction will sort most of that... 

wallofbeans

Hi All,

Quick update on this. Chatted with neighbours and they are happy to help figure out the problem. Got some photos too. There was a wooden conservatory type structure there before, and you can see where weather stripping was added to the line of that previous roof line.

It looks like the builders who removed the structure and re-plastered the wall, just did the bit that was previously inside, and I think that leaving the line might be the issue.

Although, the damp I've got coming through seemed to start at ground level and has also appeared midway up the wall, so not as high as that weather stripping line. 

Neighbours are also having paving put down this week, and wondered if the lack of it could also have been the issue...

Thoughts?

stuart45

The render would be better stopping short of the ground.

wallofbeans

stuart45 said:

The render would be better stopping short of the ground.

I'm not sure what you mean.. can you explain further?