high water table and damp from neighbour

OK - if your damp specialist said the efflorescence is due to condensation and not rising damp that's a good thing and it suggests that you do NOT after all need a damp proof membrane inserted under the floor. (So why, I ask, did he or she suggest that?)

What you need is a good passive ventilation system (i.e. one that doesn't have to be turned on to work!) In older houses, a permanently open wall vent would be the typical system. Period houses (including mine) were often built without these as there were plenty of other openings to do the job - fireplaces, loose-fitting windows and other sources of drafts!

Drying clothes on the clothes horse, along with normal cooking vapours, will contribute vastly to condensation unless you have good ventilation in place. Installing vents may solve your problem right away (any handyman should be able to do this for you, you shouldn't have to spend a lot.)

Unless the raised flowerbeds are on the kitchen wall you can stop worrying about them. Your post is ambiguous but I think you mean they are across the yard i.e. not in contact with the kitchen wall or any other wall of your house, correct?

If they ARE in contact with the house wall, I'd get rid of them. Ground level (including raised beds) should always be below your inside floor level - unless your kitchen is actually below ground (i.e. a cellar) in which special precautions (tanking) should be used.

Elaine, yes, I said I had chemical injection done in one property 10 years ago. There are signs of failure in a couple of spots (flaking paint about a foot above the floor level). I used the electro osmosis system in another house, working well but it's been in less than a year so can't comment on long term performance.

Yes, maintaining older properties has a learning curve and it's not for everyone (personally I think it's worth it but I understand why not everyone would!)
 
Hi extopia, lurdemoor and liteweight, I managed to get surveyor into neighbours house, on pretext I was interested in buying it. He reckons it is a burst pipe. We saw a large puddle of water on the floor of my neighbours shower room, which backs on to my kitchen. He reckons all the damp in my kitchen is due to this burst pipe which is flowing under my tiles, and is also causing symptoms of rising damp on other side of room. My solicitor says we will ask him to agree to fix the problem. If he does not respond immediately, an injunction will be issued. Apparently there is no denying that the damage is solely caused by the leaking pipe in his house. Apparently tanking won't do anthing due to the volume of water going under my floor from the neighbours house. So I guess it is the legal route - not what I would have wanted, but it seems the only way. Thanks a mil to all of you for all the info.
 
Id be a bit wary of that advice. It is not unusual to have a puddle in the floor of a shower! Is there people still living next door?
Your room would still need to be tanked if it is an old property. And tanking would help the problem ( in that room anyway) however it may just pushed the problem elsewhere
 
I have been reading this thread with interest - and have a small related question - sorry for hijacking!

We bought our 100 year old house last year, and had lots of work done on it. We had a DPC guy come and inject a chemical DPC, and recommended replastering to a height of 1m with a salt-inhibitor to get rid of any residual hygroscopic salts in the plaster. My builder didn't think this necessary and did not replaster.

Now we have some isolated damp patches on the wall - they form a dew especially when it is raining. They are completely isolated and do not stretch down as far as floor level.

I need to figure out whose fault it is - and whether it's worth fixing. The builder says he thinks that the DPC failed - but that he'll replaster if he's at fault. The DPC guy says that it's residual hygroscopic salts, which are harmless, and that "the cure is worse than the disease" (he has quite a poetic turn of phrase)... It's not fatal, but there are bookshelves near the damp patches, and it's making the paint flake in some spots...

So I'm not sure what to do - or who to believe. Dealing with old houses is not straightforward! Any advice would be appreciated.
 
simp said:
I have been reading this thread with interest - and have a small related question - sorry for hijacking!

We bought our 100 year old house last year, and had lots of work done on it. We had a DPC guy come and inject a chemical DPC, and recommended replastering to a height of 1m with a salt-inhibitor to get rid of any residual hygroscopic salts in the plaster. My builder didn't think this necessary and did not replaster.

Now we have some isolated damp patches on the wall - they form a dew especially when it is raining. They are completely isolated and do not stretch down as far as floor level.

I need to figure out whose fault it is - and whether it's worth fixing. The builder says he thinks that the DPC failed - but that he'll replaster if he's at fault. The DPC guy says that it's residual hygroscopic salts, which are harmless, and that "the cure is worse than the disease" (he has quite a poetic turn of phrase)... It's not fatal, but there are bookshelves near the damp patches, and it's making the paint flake in some spots...

So I'm not sure what to do - or who to believe. Dealing with old houses is not straightforward! Any advice would be appreciated.
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Your situation illustrates why many surveyors are 'wary' about the universal rising damp diagnosis. Water penetration through poor brickwork, faulty rainwater guttering and downpipes and condensation on cold spots are far more likely causes of dampness. First check if the damp spots correspond with any defects in the external facing bricks, if the the exterior walls are rendered check to see if the render is blown.
 
Duplex said:
Your situation illustrates why many surveyors are 'wary' about the universal rising damp diagnosis. Water penetration through poor brickwork, faulty rainwater guttering and downpipes and condensation on cold spots are far more likely causes of dampness. First check if the damp spots correspond with any defects in the external facing bricks, if the the exterior walls are rendered check to see if the render is blown.
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The main reason that our builder did not replaster was that he did not believe that we had rising damp at all - I had the DPC injected just in case. He attributed everything to penetrating damp.

There was some problems with the rainwater goods - which we had fixed and replaced where necessary. The room in question is properly vented, so we do not suspect condensation. But yes - the render is blown in several places. Our builder has offered to paint the brick and render with a PVC sealant to waterproof it, but I'm very reluctant to do that. (I've heard that every time you use PVC, they club a baby seal to death in Greenland.) More to the point - the damp patches are occurring mostly around the chimney breast, and not near the front wall...

I - and the builder and the DPC guy - are at a loss to explain these isolated patches of damp plaster... I am reluctant to get out another DPC firm to look things over - not sure I trust them to be objective - should I get a surveyor in to investigate?

P.S. elainem - sorry for hijacking your thread!
 
Is the chimney breast on an outside wall? How close to the chimney are the damp patches? You say that a dew is formed - do you mean that you can see actual water droplets on these patches? If so it sounds like condensation but I don't know why it would condense on specific patches unless they are colder than the surrounding wall...
 
Chimney stacks are often the source of water ingress in older buildings. Common problems include failures in flues, brickwork and mortar joints, flashings and cement rendered capping atop stacks. Get a building surveyor (with a ladder) to give it the once over.
 
It's a standard-issue late C19th Dublin redbrick terraced house. The chimney breast is half-way along the party wall. Damp patches on the chimney itself, and on immediately adjoining walls, isolated, to a height of about 1M, no higher. No droplets, just a thin film of moisture.

The damp-guy, the chimney-sweep and the stove-installer have all said that the chimney is in good condition, and that if there were a problem, I'd be more likely to see it higher up...

Just spoke to another damp company - the ones I didn't use 'cos they were expensive (false encomony) - they tell me the problem has arisen (probably) because there's damp plaster in situ, so they'll have to strip back and replaster... To do that wall will be about €1500-€2000... Which doesn't sound so bad to me... As long as it solves the problem!
 
Simp
You mentioned that the damp problem was more evident when it rained. This makes me wonder if the problem is caused by water ingress through the building fabric. The fact that the chimney breast is effected (which forms part of a party wall) makes me wonder if the stack (ie the exposed part of the chimney) is not weather tight. Water entering a building will fall through the structure until it pools or evaporates. An injected DPC acts as a barrier to both rising and falling damp. I think it would be worth checking the condition of the stack before undertaking any other works. I've attached a link which explains stacks and their typical defects.

http://www.buildingconservation.com/articles/services/chimney.htm

PS if you have a pair of binoculars you should be able to get a good look at the stack.
 
Or maybe you can get into your attic and have a look there - you might notice something.
 
Thanks for your comments about the chimney / rain. Everyone has said that the chimney is fine - but our neighbour has said that they can't install a stove because of their messed up chimney... So I hope that their issues aren't affecting us! It's worth looking into. As I've mentioned - the damp is *only* up to 1m on ground level - and if it were a general chimney issue, I'd expect to find it higher - is that logical? Our attic is fine - we use it for storage - so I can see no evidence of anything wrong with the stack there.

I came across a good article on that site you mention, Duplex, about DPCs and re-plastering - http://tinyurl.com/ioxt - and it would seem possible that our problem is not due to a failed DPC, but to a lack of re-plastering...
The importance of the replastering works associated with the insertion of chemical damp-proof courses cannot be over-emphasised. Chemical damp-proof coursing must be regarded as an integrated system, the damp-proof course and the replastering. The chemical damp-proof course will control the rising dampness and the new plasterwork will complete the system by preventing residual moisture, especially at the base of the wall, and contaminant salts in the underlying masonry from passing to the new decorative surface.
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I also came across a useful table on another site ([broken link removed], the relevant portion being:-

EFFECT: Damp patches showing on plaster as an after effect of rising damp. Occasionally, damp patches on chimney breast.
TIME & WEATHER: Before and possibly during rain (typically 'comes and goes').
PROBABLE CAUSE: Hygroscopic (damp absorbed from the atmosphere by salts in plaster & general masonry)
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This matches our experience quite closely... And chimes with what this new Damp company we're speaking with think.

But maybe I should get an independent surveyor in?
 
simp said:
Thanks for your comments about the chimney / rain. Everyone has said that the chimney is fine - but our neighbour has said that they can't install a stove because of their messed up chimney... So I hope that their issues aren't affecting us! It's worth looking into. As I've mentioned - the damp is *only* up to 1m on ground level - and if it were a general chimney issue, I'd expect to find it higher - is that logical? Our attic is fine - we use it for storage - so I can see no evidence of anything wrong with the stack there.

I came across a good article on that site you mention, Duplex, about DPCs and re-plastering - http://tinyurl.com/ioxt - and it would seem possible that our problem is not due to a failed DPC, but to a lack of re-plastering...I also came across a useful table on another site ([broken link removed], the relevant portion being:-



This matches our experience quite closely... And chimes with what this new Damp company we're speaking with think.

But maybe I should get an independent surveyor in?
Click to expand...

I think correct diagnosis before treatment would be doctors orders.
 
Get the surveyor in by all means. But as you were told before, "the cure may be worse than the disease." Maybe you can live with this, or maybe the 1500-2000 to replaster one wall (an outrageous quote that sums up the times we live in) is worth it to you.
 
Hello Elainem,
You are getting some very helpfull responses from people, which is a good thing! You really need to get someone with experience that you can trust to come out to your property and really look into the problem for you. No-one is able to give a diagnosis of the problem with out first seeing the property. The dampness could come from 1,2,3,4, or more problems combined. My reading of the problem with your neighbour is that if an engineer has looked at the property and he says he is certain that there is a leak in his pipework, then you should relay this to your neighbour and explain to him that it is only lessening the value of his property as well as yours. He could also put a claim into his insurance company which would pay for the damage to your property as well. The insurance policy should cover the homeowner for the damaged caused by the pipework. As you think the damage is coming from his supposed leaking pipe, then in my mind you are covered on his policy. If you want more information, you can send an email to my address,
Good luck with whatever you do,
Trowel.
 
Duplex said:
I think correct diagnosis before treatment would be doctors orders.
Click to expand...

Of course, the damp company will give me their opinion, but it will probably involve a lucrative job for them... Would a standard surveyor do the trick, or would it be better to engage a specialist in these matters - and if so, would anyone have any recommendations?
 
simp said:
Of course, the damp company will give me their opinion, but it will probably involve a lucrative job for them... Would a standard surveyor do the trick, or would it be better to engage a specialist in these matters - and if so, would anyone have any recommendations?
Click to expand...


I'd suggest that you ask a Chartered Building Surveyor or a Civil Engineer for a quote on the cost of an opinion as to the cause of the damp patches. (you don't require a full structural survey)
 
I just got off the phone after a 15 minute chat with a guy from Pat McGovern's Chartered Building Surveyors - whom I'd seen recommended elsewhere here on the forums. Refreshingly, he told me that he'd rather try to isolate the problem over the phone than put me to expense!

Based on what I told him, his hunch was that it was the chimney - as you yourself suggested, Duplex - since the damp only comes during rain, and is close to the chimney breast. So I'll ask our builder to have a look...

Thanks for your suggestions!
 
Hi! all. I'm now even more confused. The architect who renovated the house for my mother in 1989 had a look at the damp. He is arranging for plasterer, and someone to remove and replace kitchen units. He would not write a report to say that all the damp was coming from my neighbour's house, he said he thought it was a contributory factor, but wouldn't say how much he felt it was contributing. We didn't manage to see next door, but I had one good photo of the pool of water on my neighbour's floor. He feels that the walls should be tanked, and the tiles removed so that the original dpc membrane on the floor can be brought up to meet the tanking. He couldn't tell me why the damp is so excessive, or where it is coming from, despite my questioning him. Has any one any comments on this? I feel like I'm going around in circles, between what the engineer said - that it is a leak from my neighbour's pipe - to what my architect is saying. Do I need to get a chartered building surveyor e.g. someone like Pat McGovern to give me a report. The other engineers report wasn't for court.

Ludermor - if I do tank the walls you mentoned there was a possibiity of damp moving somewhere else - is this true? What other problems could tanking create?

What a mess.


Thanks again to all of you.

Elainem.
 
Elaine,
If you tank the room then you are only sealing that individual room. If there is damp getting the far it will just move around until it find another route out, you will just be moving the problem from one room to another. It will depen d on the outside level of the ground and the level of the kitchen, (i think you said earlier that the room is below ground level) If so and the kitchen is below the rest of the ground floor of the house you might be ok
 
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