Dampproofing wallpaper barrier removed from walls

[Suzanne]

I was a little hasty to get my Victorian 1890s house back to its original state and as I was removing wallpaper I found a layer of multilayered paper - white paper, thick black paper, metal or aluminium sheeting - and tried to get the stuff off to free the walls. They are now damp - and I realise that it was a damp-proofing paper that had been put up. The main outside wall perpendicular to this wall is about 4 feet under ground and has been lined wiith plasterboard on each side of the 2 fireplace surrounds in the 2 rooms.
As the wall in question has a stone (and earth) staircase on the other side of it outside, the damp continues to come through it and the wall is pretty crumbly. I think my only option is to have this paper re-hung - can anyone tell me what it is, where I might find it and whether I can hang it myself? Or is there an alternative to this that would solve the problem?
Thanks for any suggestions

Suzanne

 

[pete]

the wall is pretty crumbly

I'd imagine that this is a result of the 'damp-proofing paper' effectively trapping the moisture in the wall, if you could stop the damp penetrating the wall, and then let the wall breathe, things ought to settle down. The paper, and the plasterboard you mention, could just be masking the problem, and not actually solving it.

A couple of things I'd take a look at to start with:

• Is the earth meant to be be part of the external staircase?—this could be holding moisture against the wall.

• Do the stone steps angle towards the wall?—this could be diverting rain onto the wall.

...and I'm sure there are other possible causes to investigate too.

- Pete

 

[Penners]

I'd imagine that this is a result of the 'damp-proofing paper' effectively trapping the moisture in the wall

A reasonable proposition, but I'm not sure that just allowing the wall to breathe will necessarily resolve the damp problem. After all, why was the damp-proofing paper put up in the first place? Clearly there must have been a damp problem in the wall beforehand.

However, I do agree with Pete that you should be using your Sherlock Holmes muscles to seek out the fundamental source of the damp - once that is sorted out, then allowing the wall to breathe should dry it out.

 

[NT]

IIUC this is damp on in _internal_ underground wall. If so, it will in most cases dry out by itself. But not always.


NT

 

[Matt Green]

IIUC this is damp on in _internal_ underground wall. If so, it will in most cases dry out by itself. But not always.

If it has a solid brick and earth set of steps on the other side of it, its not a usual case and not likley to dry out if the room is occupied and warmer than the outside.

It should be treated as earth-retaining and dry-lined. Isolate any timber battens from the masonry with a DPM or similar.


Matt Green

 

[Suzanne]

Thank you for all your replies, an I've done some Sherlock Holmes-ing that neither myself not the surveyor were able to do when I bought the house as the room was completely filled with boxes and inaccessible.

The outside (end of terrace) wall is built into a hill (road) and the back side return wall has a solid stone staircase against a third of the wall hence both can be considered to be 'under earth' or underground. The outside wall has had dry lining done (hollow sound when I knock in the alcoves).

I've had some damp companies in who are recommending scraping the walls back to brickwork and tanking with Sika. This seems like a radical assault on the old breathing walls, but they are quite wet and being under earth I imagine they will remain so.

As I scraped off the membrane that had been holding the water back (in the bricks) and the water is seeping through - not in streams, but quite wet to touch, also around the chimney breat between the drylined alcoves - from coming through to the inside wall I'm a little stumped at what alternatives there are to tanking. The idea of having a solid rendered wall that doesn't breathe is not what I had hoped wold be the recommendation, but I've been offered no other alternatives.

Any advice on to pros and cons of tanking would be appreciated. I will also search the forum as I'm sure this is a problem many of us face.

Thanks

suzanne

[/img]

 

[Nemesis]

I would avoid tanking. It means the wall is still wet, and is wet under pressure. Eventually it may give - which is the reason why weep holes are left in retaining walls in gardens for example.

I'd consider a ventilated cavity instead.

If you look at the Agony Uncle page there's a reply by Stephen to someone with a similar problem, descibing what to do.

http://www.periodproperty.co.uk/uncle092002a.shtml

 

[Suzanne]

Dear Nemesis

Thanks for you reply. I've done more sherlock holmes-ing (funny thing is I'm reading a book at the moment about Arthur Conan Doyle) and been to many wesites and organisations, but am not much clearer on how to proceed.

I haven't figured out how to insert an image on this site, which would make things clearer. This is a rudimentary diagram of it:


[I've seem the message on the site and all the spacing has shifted lines , but I'll leave it in anyways, though its not really useful].

|end of terrace outside wall, height of earth level
| |
| window |
|__| |______| |door and extension wall of side return
|__| |
|__| |
|__| |
|__| side return |
steps ground level

The room wall has a soild earth staircase ascending to about 1.8 metres at the corner of the end of terrace house., and brickwork to the top level of the stairs has been covered with a rough, white painted cement render. The outside end of terrace wall is built into earth, a road that slopes down towards the front of the house. this basically means that inside the house the theleft part of the wall with the window behind the steps is in direct contact with what I imagine is earch under the brick and stone steps. The end of terrace wall is under the level of the road. The alcoves have been dry lined.

I checked the Agony uncle page you suggested and found this informative:

"Externally ensure that ground levels are sufficiently below the internal floor level, approximately 150 mm, and ensure breathability to the bases of the walls. This will then mean that ground moisture under and around the building can escape before rising to cause any significant problem within the property. If you change the floor to concrete it will cap ground moisture and drive it out and you will probably then find problems occurring to the chimneystack, to the perimeters and wherever the damp proofing has not been 100% effective."

As I can't lower ground levels or remove the stone steps, the corner of the room will always be in permanent contact with wet earth and this is where the moisture is coming from (not condensation as I ventilate well) as I stripped off an existing DP covering, I imagine its been a problem in hte past. I don't think the wall or the chimney breast (on the end of terrace wall) will dry out, am loathe to tank the whle thing with concrete, and run horizontal and vertical DPCs, which is the advice I've had from 2 companies. The wateris there, and I fear it will push itself elsewhere if a waterproof tanking is put in.

As the house is 110 years old, I imagine it must have been built into the side of the read using materials that would take this into account. All teh plaster and cement patching on the walls have pretty much replaced the original lime plaster.

So I'm quite baffled as to what seem to be 3 options: tanking and DPC, dry lining with an air gap and DPM on the wall, or living with wet walls. I'm thinking of getting an independent survey done, but such experts are difficult to locate.

Again, I'd be grateful any experience or comments from those of you with similar problems.

Thanks
Suzanne
[/img]