Mould on conservatory wall

[JennyWreny]

Hoping someone may be able to advise on this problem that my DParents have with their conservatory.

The conservatory is on the back of the house and square with a solid brick wall on one side and the other two sides are low brick walls with glass walls (fourth side obviously attached to house) - hope that makes sense.

The solid brick wall has developed mould recently. This wall is the boundary of their property and next door have a similar conservatory but their wall is built about a foot away from my parents' wall. We are wondering if there's a build up of vegetation or something between the walls but we can't get to the gap because it's too small and obviously on next door's property.

The conservatory has been there for about 15-20 years and they haven't had any problems in the past. Next door had a new roof put on their's in the summer but unless there's a problem with their guttering then not sure how that would have affected it.

I'm wondering what the best course of action is - maybe call a builder or get someone to do a damp survey.

Anyone have any suggestions?

If it's mould that means the humidity is high and the wall is cold. That isn't really surprising in this weather, but there may be warm damp air leaking from your house to your conservatory.
We have had a lot more humidity this year, previously our heat recovery unit hasn't captured any condensation at all, but this year with 5 of us in the house it's already condensing a lot overnight. We wouldn't really have thought about that as an issue, as it seems such a small change. Could be you have something similar changed?

Sounds like condensation to me. Maybe a humidifier would help as would more heat. Lakeland's mould spray is the dogs bollocks for cleaning mould & keeping its away though. Way better than anything else

DEhumidifier is the right one, if you put a humidifier it would just make things even worse! 😄

John, Yep, your right, I thought I had written that, bloody autocorrect is driving me nuts atm 👍🏻

Yeah sometimes it's a bit too clever for its own good!

Thank you so much. I’ll take a look at dehumidifiers and I’ll head to Lakeland for the spray.

does anybody drape wet washing in or near this room?

No wet washing around there. It's very odd. They have a small radiator that they keep on low. It's strange that it hasn't happened before - although johnd2 mentioned that there's higher humidity this year.

My DSis has a friend who is leaning us a dehumidifier, so fingers crossed that will help.

some photos would help a lot. Id the wall about 4 inches thick, or about 9 inches thick, or about 12 inches thick?

If it has recently started, I suspect water is coming off the roof of the neighbours building, though there might be vegetation or rubbish in the gap. Try and see into the gap from above, or by holding a camera or mirror over the fence.

Thank you @PigletJohn

These are some pictures I took before we washed down the wall the other day. I'm going to go around there tomorrow. I'll see how thick the wall is and see if I can see into the gap.

Sorry, pics didn't load!

I don't know what those pictures are showing. Can you add some narrative, please.

I can make out two pitched roofs meeting in a valley. I can't see the guttter arrangements. That sort of structure can be relied upon to create water damage if not very well built by a expert roofer. Leadwork used to be best, but there are modern valley systems made by roofing component companies. In my early life I once cleared old valleys that had been choked by heavy snow and were leaking into the building below as it melted.

Be prepared to ask around for recommendations of a good local roofer. You need to see their work. Somebody who does the Parish church may be suitable.

Not someone you saw online, and not a conservatory company.

Sorry, they aren't very clear!

Pic 1 (with wooden bookcase in bottom left) is mould on bottom of wall which is the boundary wall.

Pic 2 (with pole) is top left of same wall - where conservatory wall meets house.

Pic 3 (with cable) is a very strange angle but you can just make out the socket which is near the bottom left of that same wall.

Pic 4 roof - shows my parents roof on left (white guttering) and neighbours roof on right.

I've added a couple more photos of the roof which show the guttering a bit better.

Thanks again for your help.

is that rubbish in the white gutter? It looks like felt or membrane has flopped into the gutter, among other things.

I can't see a corner piece. Is it two straight pieces pushed together? Please tell me they haven't tried to hold them together with tape.

I can't see the gutter on the LHS roof.