Rising damp and water pooling

Paul_C

Hi
Looking for a bit of advice on what I believe to be a rising damp issue.
My parents house is a 4 bedroom bungalow built around 1984, Standard cavity wall construction with 25mm polystyrene board insulation in the cavity. The cavity was pumped with a bead about 2 years ago. Permanent vents were installed in all the rooms along with openings along the soffit boards to ventilate the attic space. Attic space is not a habitable space with insulation in between the ceiling joists. Single glazed windows throughout. Small granny flat extension to one side with very similar construction spec, built around 1993. Standard enough build with no real issues to date.
House is located on a 3/4 acre site at the bottom of a hill, probably around a 30 degree incline, Site is levelled in and around the house with a tarmac drive.
Over the last 4-6 weeks we have noticed some damp spots on some of the internal walls in the house (see attached photo). These walls are well exposed and not located behind wardrobes or covered in anyway. This have never happened before and I find it unusual that it is showing up now. My guess is that these internal block walls are built onto a concrete foundation and that perhaps there is some water pooling in this area that's not draining away properly and through symphonic action the water is creeping up the wall increasing its moisture content and causing damp spots and plaster flaking. I am at a loss as to where this water may be coming from if this is the case. One thing I thought was that the bathroom is close by and the flow into the cistern is really slow after flushing (could just be the ball cock or some other part of the flushing mechanism) so the thought crossed my mind that perhaps there's a leak somewhere causing the water to pool.
The other thing that is also baffling me is that there is also water pooling outside the house on the drive way 5-6 meters from the house, just a small puddle but definitely shouldn't be there, this problem also occurs on the laneway up to the house, about halfway up the driveway there is a definite source of water springing up from below the tarmac surface and flowing all the way to the main road. The water mains for the house is below this driveway (somewhere!) The stop valve at the house end is embedded into the concrete footpath (don't ask!). Can't figure out if there is a leak in the water mains or perhaps a spring has surfaced in this location as well as under the house were the damp spots are.
Basically I'm just trying to gather as much information on it as possible. I'm worried that it may be a more serious problem than just some damp on the walls. I am also hoping to call out an engineer that would specialise on these issues (Donegal area and any recommendations would be welcome)
In general surface water drainage and soakage has been good and heavy rain would soak away reasonably quickly. Internally the house is well ventilated and heated so I don't think that its caused by any living habits.
Any ideas or input on the matter would be greatly appreciated.
Thanks in advance

Metric Tensor

The picture didn't show up OP - would love to see it.

From what you describe it sounds most likely to be a leaking pipe. Are these damp spots at the base of the wall or elsewhere on the wall height? Any sort of "rising" capillary action is slow and will start at the bottom.

The pictures might tell a bit more.

With regards to the driveway - have you tried turning off (as much as you can with the buried stop valve) the water supply? If you stop the ballcock in the attic tank and turn off all other taps it might help you do some limited diagnostic work.

Calahonda52

OP, as you have less than 50 posts you can post links of pics.

If you post a link to the fotos with spaces in between to break it up then someone will post it properly.
eg
www. sitename .com / image

Any stopcock under sink?
What is floor makeup: suspended timber floor or concrete?

Are pipes copper and buried in concrete floor?

Any recent changes in the topography around the house: nobody building....?

Paul_C

Thanks for the replies and apologies about the lack of pictures which are at the links below, I've used spaces in between as I am a new user and cannot post any links yet:

Wall Dampness
http://imageshack.com/a/img921/5468/zWQN2S.jpg
http://imageshack.com/a/img923/4808/j8f167.jpg
http://imageshack.com/a/img922/4627/b5VZ86.jpg

Pooling on the driveway
http://imageshack.com/a/img922/5987/yp8qON.jpg

Pooling on the lane and main road
http://imageshack.com/a/img921/5985/MthpoH.jpg

Water main stop valve
http://imageshack.com/a/img923/6206/FI4enw.jpg

Sketch of house and site
http://imageshack.com/a/img922/3167/GBSgGb.jpg

Metric Tensor, The damp spots are at the base of the wall, the rest of the wall is fine. Hopefully the pictures will help clarify. I haven't attempted to turn off the water supply yet as I cannot access the valve as its embedded into the path. The other problem is that I live in Dublin and only occasionally get up to Donegal so I dont have much opportunity to investigate.

Calahonda 52
I'm not sure if there is a stopcock under the sink, I will check this out. Floor is a ground supported concrete slab, no suspended timber flooring anywhere. So far theres no evidence in the floor to suggest that its damp. As far as I know the pipework is copper and buried into this floor which is one thing i'm concerned about, It would be difficult to identify a cracked pipe unless the slab around it is damp which it doesn't seem to be. No building works or topography changes in over 20 years.

The other thing I forgot to mention and the sketch I have attached will clarify is that there is a land drain to the rear of the house to collect any water at the bottom of the sloped lawn. It then makes its way down the side of the house and drains into an existing open surface water drain along side the road. It occurred to me that perhaps this could be blocked allowing the water to collect and make its way over under the house, however this wouldn't explain why there is water pooling on the lane as it seems too far away from the land drain to be affected. I would have presumed that if this pipe was blocked that the water would be pooling in and around the pipework and would be obvious, i could be wrong though. Generally any excess rainwater (and we get a lot!) drains away fairly quickly and have never had an issue with this before.
I'll see can I get someone to check for a blockage in this drain as it would be relatively easy to check this.

If I need to do anything else in order to view the pictures let me know.

Thanks again.

Paul

BryanF

The fact that this has happen over the last few weeks suggests a leak

But Has anything outside your boundary been altered recently that could affect the ground water table?

Paul_C

BryanF,
Not that I am aware of. Neighbors on both sides have had little or no work done to their properties or surrounding site. The field behind is as it was for the last 15/20 years. I don't think any of the neighboring sites are causing this issue.
I believe it to be a leak of some description myself or perhaps even a spring has made its way to the surface?
Paul

Metric Tensor

I'm pretty sure from looking at the pictures that you have a burst pipe somewhere.

I don't think groundwater would do the damage that you are seeing as quickly as you are describing. It'd also be unlikely to just appear without major groundworks changes in the vicinity - like a local farmer draining fields or something.

PMBC

Although it might or might not be related to the dampness in the walls it should be possible to determine if the water in your service pipe is causing that problem in the driveway. The old style night waste water surveys are the way. Unfortunately its a two o clock in the morning job when no water is being used in the house, otherwise you have to turn off the stopcock/valve under the sink and tie up the ball cock in the attic. You use a metal sounding bar or a stop-cock or valve key and put it on top of the stop cock body at the entrance. Flowing water will be clearly heard. If so it indicates that either someone is using water at 2 a m or your storage tank ball valve or/and your undersink stop valve are leaking/not holding. When I did this forty years ago we always assumed that water used at that hour was leakage. I agree with other posters that water appearing in the driveway at the same time as dampness indicates a probable connection between them.

PMBC

Just saw your excellent sketch. My guess is bathroom pipework leaking. One of the wall pics show it as very bad. The second that I could open is classic rising damp with bubbling plaster.