Rising damp?! Is it a real thing?

[Iamtherealelsa]

This is my first post, please be kind :)

Ok so we have just bought a house, 2 bed Victorian terrace. The decor is not to my taste but we thought that would be easy to resolve and we had a teeny tiny bit left over from the move to rectify the things we didn’t love. 8 weeks or so after moving in, and we’ve noticed a hideous patchy area of damp across the whole of one wall of the dining room! It seems like it’s appeared from nowhere, and I can only think that all the recent heavy rain combined with colder temperatures/having all the doors shut now it’s cold has made what was evidently already an issue, obvious?!

On Monday we had a builder round to look who said that it was a result of needing to reflash the chimney (an issue we were aware of when we bought the house, but not something we thought would be an instant problem). Today we had a surveyor round who said that it’s nothing to do with the chimney and it’s rising damp and has affected the whole side of the house?!

Two things - firstly, I have read loads of stuff which says rising damp is a myth, that the water has to be getting in from somewhere and people are just out to flog damp proof courses which could potentially do more harm than good in old houses anyway.

Secondly, the people before the people we bought the house from, illegally built a tiny conservatory room into the side return, right next to the wall where we noticed the damp. We have theorised that perhaps they have not left enough ventilation/done something dodgy with the guttering/something else we haven’t thought of to do with their bodge job, that has led to water getting in somehow?! Anyone knowledgeable that can help?? Can post pics of the damp wall and the conservatory room if anyone would be willing to take a look? The other thing is that the whole downstairs is carpeted at the moment...not sure of that would contribute to lack of air flow/ventilation? We’re supposed to be getting the carpet taken up and wood flooring laid, but we’re now obviously going to hold off til we’ve sorted whatever this is.

We’re trying to settle in a new area and finding it all bloody exhausting to be honest. Would really appreciate anyone who can help with any insight

Argh it says 'new users cannot immediately post pictures' - any way around that??

not that I know of.

If you have a damp wall next to a conservatory, look carefully for an old drain (usually just outside the kitchen window) and for rainwater pipes, and for signs that water is getting between the edge of the roof and the wall. There might even have been a garden tap.

presumably there is no rain falling on that wall, or forming puddles on the paving by it.

Look for any airbricks that might have been blocked or covered up by some idiot and the damp course, which should be below the inside floor level, and about nine inches above where ground level used to be when the house was built.

I don't have a solution, but am watching with interest. My house was built in the 1830s, lots of damp issues to keep on top of...

forgot to say, my favourite, water supply pipe under the floor leaking (very common in old houses)

The pipe is pretty sure to run from the outside stopcock (next to where the front gate used to be when the house was built) to the indoor stopcock (underneath where the kitchen sink used to be when the house was built)

If the kitchen floor is concrete (very common) the water may have been leaking into it for years and soaking into the nearby walls.

If you have a water meter, or know someone young with sharp ears, you can detect a water leak easily.

if you have a house built prior to May 1945, it almost certainly has glazed clay drains and gullies (like a brown teapot) in the ground and they are almost certainly cracked and leaking. Somewhere in the country there may be a house where they aren't cracked, but I have not yet been to that house.

This is so interesting. Thank you so much you've given me a ton of food for thought and I feel much more prepared to speak to builders etc! I'm going to make a big list of things to investigate in the daylight tomorrow. The air brick point is interesting - the conservatory has two air bricks near the floor in what would have originally been the external underneath of the dining room window looking into the side return. The air bricks are not blocked in any way but they also now don't go into the outside, they go into the conservatory room! Does that make a difference? The floor in there is concrete.

What have you found?

Yes,
It can make a difference but to your floor rotting from damp. It would not cause a damp patch on the wall.

If your terrace is deep, as in two rooms deep plus, then front air bricks alone will not be enough to ventilate the underfloor sufficiently. Smaller properties that are wide but only one room deep can sometimes get by with air bricks along the front or back only. But the typical terrace is minimum two rooms deep and sonyou should have both front and back.

The air bricks should always ventilate to the outside especially since it sounds like you have a suspended wood floor in the dining room (you mentioned taking up carpet )

Normally, the airbricks would have been extended under the conservatory floor with ducts and new air bricks put in conservatory wall below floor level to outside.

I think though the only things you can do now is either

1. resite the air bricks on the same back wall but outside the conservatory. (Or)
2. put a vent in the conservatory itself to encourage air flow through the air bricks if they open into the conservatory itself. This means your conservatory isn’t really a heated/sealed area though (Or)
3. put channels in under the conservatory floor to extend the air bricks very very expensive.

So far nothing obvious from the weekend's investigations. We have a builder friend coming to have a look next week, so I'll update them. In the meantime, here are some pics. Looks awful doesn't it?

And more for context - that's the door to the conservatory room next to the damp dining room wall

Is it a concrete floor?

Looks like a leaking pipe to me.

Pull back the carpet please.

Also show the other side of that wall.

I agree with piglet. It is likely some sort of penetrating damp. Not convinced a pipe yet without knowing whether you have any pipes running through that wall.

You need to pull up the carpet and see what’s going on under there. If the floor joists are rotting and damp due to the air brick situation, the damp can spread up the wall like that.

Is that wall shared with conservatory? Or is it exterior? What’s on other side of that damp wall? A picture would be lovely.

Would you be able to draw a quick floor plan with the damp bit marked on it? You said it’s next to the conservatory door, but it’s next to a radiator in your pictures.

Is the skirting board new? it looks it to me in the picture like it might be. Original Victorian skirting board is much wider/taller than what you have and usually has a bevel on top. So your skirting has been replaced at some point....
So quite possible for wall and floor to be damp but skirting ok because old wet rotted stuff has been replaced in summer to make it cosmetically mask the damp for house sale.
Sellers can be devious as fuck.

@PigletJohn is the expert on here but if you pull the carpet back you may see if the concrete floor (if you have one) sweating. If not obvious, place a heavy book in the carpet and leave for a few hours. We found a leaky central heating pipe this way

Pulled up the carpet and found a hole in the floor with a plastic cover over it and a hardwood floor, no original floorboards. We looked down the hole and can't see any obvious wetness? OH says they is a damp proof course but has no idea if it's effective/damaged etc. There's also no smell of damp. The carpet and wooden floor aren't wet at all. The skirting board came off with little force, but seems to have been glued really badly. Not sure if it came off easily because it's damp? Or just poor workmanship? The edge of the wall near the radiator does seem to be the most affected so maybe previous poster is right and it's the radiator leaking?

I can't post any more pics until tomorrow, as apparently there is a limit. I'll add more tomorrow including a diagram of the floor plan. Really appreciate all your help again

have you got a water meter?

does your boiler have a pressure gauge?

was the "surveyor" a salesman for a damp-treatment company?

We are thinking along the exact same lines - I've just checked the boiler and the pressure is low, which I understand can indicate a leak in the heating system? Just called British Gas Homecare and they're coming out on Saturday morning to check it!

Rising damp is most certainly real!!
We have inherited a Victorian terrace which is built directly onto the ground - no foundations, no floorboards, just quarry tiles into mud. We have riding damp because of this and have been advised by our brilliant and completely trustworthy builder that we need the floor digging out and a damp proof course put in. It's costing £3500 but it's worth it.

Did you get the chimney flashing sorted out? We had damp that looked like that in a Victorian terrace and it was related to the chimney.

With that added detective work you’ve done OP, it could be a leaky radiator pipe. Glad you’ve got someone coming in to check the boiler and system. Keep us posted.

Thanks so much all. Still have our builder friend coming to check out the chimney and everything/anything after half term, so no - not sorted the flashing etc yet. British Gas booked for Saturday morning. Will keep you posted, you've all been amazingly kind and helpful! I'll definitely let you know the outcome

Do you have any pipes under your floor? I had damp just like that in a previous house and it turned out a pipe was leaking underneath the floor, which was causing the damp. It was buried in a concrete floor unfortunately but we managed to reroute it over the ceiling instead. Once that was sorted the wall dried out and we didn't have any more problems.

No idea if there are pipes under the floor but another thing to consider for sure...mentally noted.

I got this picture of underneath the floor, can you see the piece of wood at the top? It's half soaked with water and half dry...it's coming from the chimney breast towards the alcove where the damp is. So maybe a chimney breast issue?

British Gas reckon that it's not the radiator but he barely looked at it to be honest, he sorted out the boiler pressure and said that apparently it's normal for it to drop a couple of times a year and need re-pressurising. I'm going to keep an eye on it for a couple of weeks and call back if it drops again.

In the meantime, we'll wait for our friend the builder and I'll also see if British Gas will send a plumber as we are covered for plumbing and drains. Not sure if they'll do much investigative work but I guess worth having the conversation?

Have you got a water meter?

I have nothing to add but bizarrely find this thread fascinating.
I’ve realised that in my 1947 house I don’t have any air bricks but then my floor is solid concrete and all above ground level.

(I also really like DoctorAllcome’s drawings.)

Good luck sorting that damp OP.

Thanks @FlamingoAndJohn 😊

@PigletJohn - no water meter...is there a way I can find out if we're using more water than we should be? Check my online account with Southern Water?