Advice required - damp upstairs room

[MattTB]

Hello,

I'm looking for some advice on what type of tradesman would be best to help on an issue I have in my property. Would massively appreciate any help given.

I have an upstairs room which has a roof terrace/balcony coming off it. In this room, the interior of the exterior wall has damp. The photo I have attached is the current state of this wall. Would note that it would not have naturally looked quite this bad... I decided to start going at it with a scraper when I was hoping that it was perhaps an old problem that I could paint over.

The damp doesn't appear to be coming from above (based on where the damp is) and I've observed the gutters when it's raining and can't see any leakage. I'm currently wondering whether it's caused by the fact the balcony wooden frame is attached to the wall and the balcony wooden slats are pretty much touching the wall. If it is, I could cut the balcony slats a bit with my jigsaw but obviously that doesnt stop the fact the joists are going into the wall. Apart from that, really not sure what the problem is. The render on the building itself doesn't sound hollow.

I only moved in 6 months ago and so I don't know how long the balcony has been in place. I know it was part of extension works at some point.

Photos attached. Happy to respond to any questions - I could really just use a point in the right direction. I'm a little hesitant to just contact a damp proofer because I would ideally like to treat the source of the problem rather than just inject the walls.

Thank you,
Matt

 

[justbigboned]

I've seen this a lot on properties where the tarmac runs right up to the exterior wall. Buildings need to breathe. If you have concrete paving slabs right up against the exterior wall, I'd suggest thats likely to be your problem. The moisture in the ground has nowhere to evaporate to so leeches into the fabric of the building. Also, are there sub floor vents and are they all blocked?

I will try to find some visual examples for you and post again.

 

[MattTB]

Thank you for responding.

In this instance there are no concrete paving slabs, it's a timber base for a balcony/roof terrace (see pic from ground floor looking up) and no air bricks as it's on the first floor of the building.

 

[justbigboned]

Below you can see where the tarmac abutts the brick wall. There is clear evidence of damp in the lower quarter of the brick work as moisture is unable to escape through the tarmac. It's surprisingly common, especially on properties that bound pavements on main roads, where the council slap the tarmac right up to the wall.

 

[justbigboned]

Thank you for responding.

In this instance there are no concrete paving slabs, it's a timber base for a balcony/roof terrace (see pic from ground floor looking up) and no air bricks as it's on the first floor of the building.

Is that roofing felt thats visible below the deck level?

 

[justbigboned]

Is that roofing felt thats visible below the deck level?

Nevermind I can see it is.

 

[justbigboned]

I can't delete the now somewhat irrelevant posts above, although I suppose they are related.

In terms of which professional to approach I'd probably suggest a chartered surveyor. I'd have expected an issue like this to have been picked up during your survey at the time of purchase. Again, a surveyor should be able to advise on whether or not you have any kind of recourse to the original professional.

I think you're right and the moisture is likely going to be coming from those wooden beams depending on how they have been installed. There could also be splashback from the decking and maybe the run off of the felt or deck isn't quite at the right angle and/or sufficient. There is evidence on the left hand wall of excessive mold suggesting that water frequently sits there.

You definitely do not want to cover this up or paint anything over. If it were me, I'd take off the internal plaster and try to gauge the extent of it. Do what you can to help it all breathe. Keep the room ventilated and I'd also suggest heated if possible.