Damp (again)

[No23]

I have read with interest the various topics on damp on this forum. However, I have damp in several places and the worst of it is where my house joins the neighbouring property (I live in a mid-terrace about 100 years old). I can't see any obvious reason for it and with it being an interior wall, it's not a case of the soil or anything being too high outside or a leaky gutter etc. It's fair to say though, I am no bulding expert, so I'm looking for some advice here please as the damp is quite bad and seems to be expanding before my eyes!!

Here are some photos



http://img156.imageshack.us/img156/6817/interioralcovezi2.jpg
http://img247.imageshack.us/img247/6097/interiorpartywallfv5.jpg
http://img157.imageshack.us/img157/9372/exteriornearwindowza8.jpg

 

[JohnD]

Is this on the ground floor? If you take a floorboard up, does it smell damp under there? Can you see any concrete, or is it just earth (or mud)?

Do you speak to your neighbours? Are they conscious of damp, and have they (or you) made any alterations to the floors?

Where does the water main run in relation to this damp wall? And the drains? Is it close to a bathroom or kitchen?



(I am assuming, by the way, that you don't hang wet washing about the house, or use a shower or bath with no extractor?)

 

[No23]

John thanks for your reply. I have not lifted a floorboard as yet and the neighbours don't seem to have a problem (or they aren't admitting to it).

The damp is all on the ground floor, but those pictures are all on different walls. One in front living room and two are from the rear dining room but on opposite walls to each other. Also, I'm not sure of the route the water mains take through the house and the damp is not near any drains. Apart from the front living room, all the damp patches are in the middle of the house.

 

[JohnD]

If you locate the stop-cock by your front gate, and the cold water pipe that comes up through your kitchen floor, you can assume the water main runs between them. It is not unusual for old water mains to leak. Clay drainage pipes, and especially gullies, tend to break, especially on houses built on clay, near mines, or having been in an area of WW2 bombing.

As it is the interior walls that are wet, and your house is 100 years old, can you see signs of a damp-course in your walls? With either a double row of slates in a thick mortar joint about 6" above where the ground level was when the house was built; or a couple of courses or dark red or blue shiny brick. Or maybe a more recent chemical injection with a row of holes clumsily filled with mortar. In which case perhaps the outside walls were done and the inside walls weren't.

When you bought the house, did the survey mention damp?

At the moment I am thinking about a water leak under the floor. It might be yours or your neighbours. I expect the plumbing is very old in both houses (unless one of you has had e.g. central heating pipes or a washing-machine tap fitted)

 

[No23]

John, thanks for your further reply.

The stop cock is in the kitchen which is at the rear of the house and the water main runs form the back lane so I would think it reasonable to assume that the mains don't run through the house. The bathroom is upstairs above the kitchen more or less.

The front and rear of the house both have signs of a chemical DPC and the rear extension (i.e the kitchen) you can see the damp proof membrane bteween the bricks, None of this appears to be bridged, but then this isn't where the problem is.

I should also have mentioned that the two affected exterior walls join the houses either side of mine.

Also, in your original reply, I must have missed the bit at the end but it's very rarely that any wet washing is hung in the house. It's either on the line outside or, in cases of wet weather, put into the tumble dryer which is located in a utility room that is separate from the main house. Also, the bathroom does not have an extractor, is fully tiled and we open the window when using the shower. We rarely have a bath, preferring to use the shower 99% of the time.

It's got me stuck this one and I really don't know where to start in trying to locate the source of the problem.

 

[JohnD]

The front and rear of the house both have signs of a chemical DPC and the rear extension (i.e the kitchen) you can see the damp proof membrane bteween the bricks...

... the two affected exterior walls join the houses either side of mine.

If the party walls are wet, and the front and back aren't, I am now wondering if the party walls need, but did not get, a chemical dpc injected?

Have you had a look under the floor to see how wet it is down there?

If you neighbours will let you in for tea, have a squint at their walls for signs of damp and tide-marks.

If you can pull off a skirting borad, e.g. under the stairs, see if there is any sign of a dpc; how far down the plaster goes; and if the bricks look wet.

 

[Static]

Where in the UK do you live? also how damp is your garden? and how long have the walls been damp, as it looks fairly recent?

 

[No23]

Thanks for the replies.

I have not lifted a floorboard as yet because we have laminate flooring throughout the downstairs but I suppose I'm going to have to get on and do it. On the subject of chemical dpc's, after reading this board over the last few weeks it seems they are a waste of money, though I may be wrong on that score.

Static, I live in Wallsend to the east of Newcastle upon Tyne. You are right in saying it looks fairly recent. It seems to have appeared from nowhere. Also, it is a terraced house - front door straight onto street so no front garden and we have a yard at the rear.

 

[Static]

As johnd suggests check below the floor near the damp walls.

 

[No23]

As johnd suggests check below the floor near the damp walls.

Okay, I'll do that, but what I am looking for?

Sorry to sound so clueless, but apart from a bit of decorating I'm a bit useless at DIY/building.

 

[JohnD]

It will be interesting to know if the house has plain earth below it, or any kind of concretre raft or rubble, and how wet this is.

It will probably be a couple of feet below floor level, and there may be honeycombed sleeper walls to support the floor joists. You might see slate dampcourses in the sleepers or party walls. Or you might see cracks that have not been hidden by plaster. You might see pipes, e.g. central heating. There is a chance you might even see a leaking pipe. You might even see a wooden chest filled with doubloons.

The earth or concrete may be dryish, dampish, wet, or submerged in water.

If the level under the house is lower than the level outside, it might have turned into a pond or marsh if there was e.g. a burst pipe nearby or in one of the houses.

We did have someone say that in his area it was common to have standing water under the floors, which sounds almost incredible to me.

(what I really mean, is that the damp affecting your walls is almost certainly coming from under the floor, so we are looking for the reasons why)

 

[Static]

Best check the joists while you are doing this to make sure they arent rotting.

 

[No23]

You've got me scared to look now as I don't know what I'm likely to find. I know there are lots of old mine workings in this area if that makes any difference.

I will lift some floorboards in the morning when I have plenty of time to explore and let you know what's there. I'll take some photo's to assist. I have a feeling this is going to cost me a few bob to put right though.

Thanks for the replies guys. It's really appreciated.

 

[Static]

You've got me scared to look now as I don't know what I'm likely to find. I know there are lots of old mine workings in this area if that makes any difference.

Yep finding a mine shaft down there would be scary.

 

[No23]

You've got me scared to look now as I don't know what I'm likely to find. I know there are lots of old mine workings in this area if that makes any difference.

Yep finding a mine shaft down there would be scary.

Oh I don't know...a source of cheap coal. I could always reinstate the open fires