Hello all,
We have been away for 10 days or so, no heating on in the house and have come back to one chimney breast wall, and the external wall connected to it either side, actually wet to the touch on top of the plaster.
Not aware of it happening before - not since we moved in 3yrs ago - but defo had been a historic problem as I had to patch in the plaster as one of first jobs.
There is a cellar below, not too damp and has air bricks etc.
The brick supports down there seem ok, not damp particularly.
The chimney is blocked up at ground level inside but has pots with cowls on at the roof and an air brick half way up the external wall.
Pointing outside could be in better shape, but the area where walls are damp is higher than external ground level by a fair bit, and well drained on that side (gravel drive) - which makes me think chimney issue/water coming down rather than damp from ground being drawn up.
House is 1910-ish semi.
Anything glaringly obvious to anyone that it could be/best practice to resolve?
I have another similar room but with a wood burner fitted, and back to brick on the i herbal walls. This has no probs other than a few salts coming through the bricks.
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You can see the damp spreading up from skirting at the corners and along into the wall running away from chimney breast.
This is the outside - floor level inside is roughly where that black cable runs horizontally:
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Has the chimney been capped with air bricks at the top? I had a problem with mine where a boiler had been hung on the kitchen wall (many years ago) and the flue run up through the old uncapped chimney. This boiler had then been moved but the lengthy flue left in the uncapped chimney, allowing heavy rainwater to accumulate against the kitchen wall over time.
Easily sorted by removing the flue and capping but it took a while to work out what was happening!
I can see 2 of the little steel flue/spout things that you often get when an old gas appliance had been there (which is the case here).Originally Posted by Peck
I cannot see the top but assume they are capped and then just vents in the side (which you can see).
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If you know anyone with a drone may be worth just checking the cap on the roof. Looks pretty wet at the bottom there
My expertise runs no further than owning several houses, but surely that damp on the wall is rising up rather than running down?
Also we had what we thought was a rising damp problem in one house, which turned out to be a blocked gutter drainpipe, which meant the gutter overflowed down the wall outside. Didn't realise until coming home one day during a downpour and saw it happening!
Last edited by oldoakknives; 11th January 2022 at 17:57.
Started out with nothing. Still have most of it left.
Can't make it out but what is the grey fabric showing in the pic?
The pointing does look like it needs replacing anyway, I would also take the socket of and see how damp it is, you don't want electrics tripping as well.
You’re probably right, it just looked really wet to me which made me think of my situation a couple of years back.
Yep, defo not running down - but with no plumbing in the area, and being feet above ground level, I cannot see where it would be coming up from.
Unless it is coming down or into the chimney, pooling somewhere then coming up from that - but I struggle to see where it could do that.
I can be in the cellar directly under the damp wall above, and see bricks below it that do not seem damp.
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I’ve had something very similar which I thought was rising damp. I recall another thread here going several pages long where the consensus from many more qualified members concluded rising damp is unlikely the cause in the majority of cases.
I believe the issue in that thread was solved by a builder assessing the situation and rectifying the problem for a significant saving on damp proofing/rising damp treatment. May be worth the smaller cost for a trusted builder to have a look first if there’s no obvious cause.
I’m thinking Your damp proof course is failing.Walls will then suck water upwards
Is there a damp course on that wall?
https://www.richardsonandstarling.co...s-rising-damp/
Started out with nothing. Still have most of it left.
Can’t actually see a DPC from the pics, but there is a lot of discolouration on the brick courses below where one might expect to see the DPC. Also hard to tell from the pics but do you know if the building has cavity walls?
Surely they didn’t use a DPC in 1910?
Of sorts. Slate bitumen and engineering bricks were used .
A bit odd.
Looks like you have damp on both the chimney breast and the adjacent wall in equal measure.
It doesn't look like water pooling at the bottom of the chimney, because you have damp running in a fairly level line along the adjacent wall.
Equally it doesn't look like the DPC has been bridged by crap in the cavity, because that would tend to shunt water running down the inside of the outer wall across to the inner wall. You have damp on the chimney breast & that's not an external wall.
I'd go for damp course failure, which is unlikely as the Victorians tended to use slate, crap in the cavity causing rising damp, or a failure of the roof or guttering.
As access is so easy, I'd take a brick out on the exterior wall below floor level & have a look. Find the DPC and check that any muck in the cavity isn't bridging it.
You may need to shove the brick back in and wait for a rainy day to check for water coming down the inside of the wall. Don't leave the brick out, because rats will come in.
I’m no expert however having recently sold a house with a reported similar problem and subsequent inspection by a damp expert- i was told that water can ingress through the mortar and follow the wall ties, as i said I’m no expert.
I’m probably talking rubbish - but could a really heavy downpour hit that fabric (car cover?)and go straight into the air bricks?
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To add even more confusion, there is damp on a very internal wall - one that runs 90degrees to the external walls, and the damp only appears about 2 metres in. Dry between there and up until the external wall.
Again no plumbing anywhere nearby.
I can only imagine water being drawn up somehow? But it is 2m up a wall that starts in cellar. I can get to both sides of the wall in cellar and see no obvious damp - yet above, in the lounge and dining room (both sides of same wall) I find a big damp patch.
Odder still, it also surrounds a plug socket!
If I did not know better, I would say that water is tracking the power cable and soaking into wall where it reached the sockets
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Is there any correlation between the areas of damp and the positioning of furniture against the wall? With the building having a short period of being unheated I’m wondering whether this could be a condensation issue where damp air gets ‘trapped’ behind sofas/shelves and then condenses on the cold walls.
There won’t be a cavity as some are suggesting in a house from that time period. You’ll have a solid 9” wall.
As for rising damp that’s a myth it doesn’t actually exist and injected dpc are a con so don’t bother.
First check all your pointing and look for gaps / powered mortar. Next check the vents to see if they are providing airflow or are blocked.
Also have you got a drains issue ? Do you know where the drain run locations are ?
And finally as someone has suggested above the rain could be hitting the cover and entering the vents.
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I wondered this too.
Away for 10 days.
No heating.
Assume all windows were closed.
Was any source of water left, such as a full sink or clothes drying indoors?
We had something similar in a previous property which turned out to be condensation forming on a cold wall behind a sofa.
Problem was solved by stopping leaving the kitchen sink full, opening a window or two downstairs for an hour each morning, and reminding my wife to use the bathroom extractor fan.
I had a damp problem in a heritage property, got a damp specialist in via this website, he did all sorts of tests alongside the survey, and all the solutions recommended (mainly work a builder could do) worked brilliantly.
Funnily enough, none of them were an injected damp proof course, which the house had had in the previous 15 years anyway, and had done nothing.
https://www.dampdetectives.co.uk/
Injected damp proof courses are a big con IMHO, and cause more damage and problems than they ever solve.
If rising damp is a myth, why do modern houses all have a damp proof course? Surely it would be unnecessary.
Started out with nothing. Still have most of it left.
Could damp be entering the property somewhere else and migrating through the walls ‘above’ the dpc
The dpc could be stpooing the water going down ( as it prevents it from rising)
Maybe a drive or path at the front of the house that is above the dpc..?
Have the walls been plastered with the correct backing coat ? It may be, if it's not the original plaster, a premixed base coat ie. carlite bonding, that effectively acts like aa sponge absorbing atmospheric moisture in a cold unheated property. Not the product to apply to solid non cavity walls. Just a thought ?
My money would be on condensation. Have any air vents been blocked or left closed?
The row of "headers" (ends of bricks only showing) just above the black cable would suggest a solid wall with no cavity and damp could track upwards, or through if there is no, or a failed dpc. The damp would normally evaporate away when the house is heated.
Last edited by tixntox; 12th January 2022 at 10:02.
He said 1910, not 1810.
OK that's new news.
If the water was flowing through or along your power cables, the supply would be tripping. It's freakishly unlikely that you'd get this problem at multiple sockets.
Turn the power off, unscrew a socket and look. It's easy and if the power is off, safe. If you're not confident, just don't touch the terminal connector screws inside the socket. Simply undo the two external screws, pull the socket forwards and have a gander.
It's not plumbing. There isn't any.
It's not rising damp. You've checked the wall in the cellar below.
It's not a bridged cavity or a roofing failure. You have the problem on an internal wall.
Are you certain its not just condensation? That's about the only thing left. Occam was clean shaven you know.
We have at least two houses that are single skin, both built pre 1930.
"Once is happenstance. Twice is coincidence. The third time it's enemy action."
'Populism, the last refuge of a Tory scoundrel'.
Yes cavity walls weren’t the standard until the mid 1930s.
Majority of homes pre 1930 are all single skin 9’’.
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Cavity walls were intorduced in the late Victorian period. My first house had them and was built in 1896. They were extremely popular by 1910 and by 1920, pretty much everything was cavity built.
A 1910 house could be either.
The row of half bricks is called English bond. It was used in single skin 9" walls. It was also copied when they started making cavity walls. They just snapped the bricks in half.
It is a pointer that the wall could be solid, but it isn't a guarantee.
For added confusion - our (pretty ordinary) 1908 semi has cavity walls :)
I would have said condensation - but that wouldn't explain the dampness on the internal wall or the chimney breast. Condensation will normally settle on the coldest (external) walls, and any single pane windows. Could there be more than one source of the moisture?
Another question - when the new plaster was applied to the walls - was the cause of the historic dampness issue fixed at the same time? What was it diagnosed as being? Presumably the new plaster was a modern, non-permeable plaster? Would it be reasonable to expect any damp penetrating in from the exterior to show as fluffy, salty deposits on the new plaster, whereas condensation to present simply as damp, wet walls?
And another - can you see the ground floor joists in the basement? Any sign of dampness coursing along them, perhaps from a single or even multiple places?
As I understand it - rising damp does exist as a phenomenon, but is quite rare and often misdiagnosed.
Something else...
You have air bricks into the cellar, but I can't see any into the ground floor room? The flooring you have on the ground floor looks to be a solid wood overlayed onto the floorboards? So no air gaps between floorboards to provide ventilation, and the fireplace has been bricked up? Is there any other form of ventilation into that room? Could it be simple as getting proper ventilation sorted - such as an air brick into the bricked-up chimney and one on an exterior wall?
Last edited by Neil.Ldn; 12th January 2022 at 12:19.
Non-cavity walls were common in Edwardian houses.
Incorrect.
English bond is header/stretcher/header/stretcher coursing and so on. It looks like you're confused with English garden wall bond.
My money's on condensation. Combat with heating and ventilation.
That black cable should also loop down and back up to where it enters the air brick, you'll get a surprising amount of water tracking the cable and into the wall.
Google is your friend:-
https://www.google.com/search?q=flem...client=gws-wiz
Google isn't my friend. 35yrs in the game is.
+1
Warm air rises meaning the coldest air is at the bottom. Absent heating the walls cool and water condenses, generally on the bottom of the walls. If you took wall readings with an infrared thermometer you'll find the wall is colder at the bottom than the top which is why the water condenses there. External walls are generally the coldest hence most prone, but internal solid walls can suffer too.
A combination of heat, ventilation and then possibly buying a Meaco de-humidifier should get you on the right track. If you know you live in a property prone to this then I'd use anti-condensation paint. It won't stop it getting wet to the touch but will help with it being surface moisture and not permeating into the plaster and creating spores. Sadly a "compromise" of older properties.
He was! I think it was condensation, as a couple of days with heating or wood burner lit and there’s no real sign of any damp left.
Surprised at how and where it built up, and always distrust old chimneys - but had a friend with a drone pop over and recce the stack and pots, all well up there.
One air brick externally, but not internally - so suspect just a cold house and no real air movement in the room for too long (2 weeks or so).
I have sincerely appreciated the level of response here, from all of you. Thanks very much.
Ha ha - you are quite correct.. but the photo is just bad. It drops down well past, then loops back up and in.
I love a bit of cabling!
Thread resurrection!
I know the cellar used to flood badly and fixed that some 2 or more years ago, when we moved in - after at least 20yrs years of it being inches deep after every rainfall!
I finally got myself a proper-job dehumidifier and have had it running for 3 days now.
It is currently extracting almost 2 litres of water every 8 hours, on a low setting!!!!
It smells drier - in fact, no longer smells - and feels so much better down there (fnar).
I reckon if I dry it out properly, the ripple effect will be solving/reducing any damp issue in the lounge (which had gone anyway now we’re back and using rooms properly).
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It’s amazing how much a dehumidifier can pull
I have a damp smell in the utility. No sign of any leaks. Very annoying as kitchen and utility were only done 9 months ago.
Plumber cannot see a leak either, but the musty smell is there. Cleaned all the pipe work, but it’s still there. Cupboard door removed, but can smell it when you pop your head in.
Very annoying but no source that I can locate
We had that as well. Including the musty smell.
The sink drain and the dishwasher drain go from two to one drain, through the concrete floor down, into the crawl space under our house. The crawl space 'floor' is sand. It turned out that the vertical sink drain/dishwasher drain had come off from the pipe that leads to the sewer, at the spot where the pipe goes from vertical to horizontal. A broken joint. We found that out when we had the solar panels installed and the wiring for these were routed through the crawl space. The guy doing the installation of the solar panels noticed wet spots of sand. Perhaps something similar is worth investigating. The absorbing characteristics of sand had made it impossible to spot wet places or even standing puddles of dishwasher water!
Sounds like a job for a dehumidifier…
My new favourite gadget!
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Agreed! My Son in Law had similar damp, bought a dehumidifier, left it on for a month and it went.
Oh! great for drying clothes too in winter.👍
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