Any builders/construction experts?

[Caro]

I'm just looking for a hint so I can go off and research the solution, if anyone would be so kind!

We live in an 1890s stone house, with no DPC. The plot is on a slope, so what is the basement at the front of the house, is the ground floor at the back.

We've recently done up the basement hallway, plasterboarded it, paint etc. However, I now have visible damp creeping up, particularly around the door frames, and the plaster and paint are flaking off This is presumably because we have no DPC and the walls are basically sitting on damp earth.

What are practical solutions to this? If anyone can point me in the right direction, I'd really appreciate it.

Thanks

[bigt1888]

can you give more info pics etc..

is there any DPC at ground level or above?

what is the plasterboard fixed to?

is there any ventilation in the basement?

[PAULW]

There is something called TANKING I know no more than that just seen it on the property programs on the tele

[bigt1888]

tanking is basically a bitumen type paint/coating that is painted onto the walls to act as a DPC but much more info is required

[green thing]

Hi caro
I just finished a job in knutsford with a similar problem
the house was stone built around 1750 no DPC
the cellar was tanked with a cement screed and render with a waterproof agent in it
this worked well but has moved the damp up the walls onto the first floor above the basement and pushed the damp through the solid floor on the front of the house rotting the carpets
the only way to resolve the problem in the walls was to render the wall with a cement render with a water proof agent (feb waterproofer) in the full height of the room then it was dry lined
the customer wanted the walls insulated as well
we dot and dabbed 30mm insulation (celotex double R) on the walls first then fixed tile battens horizontally at 400mm centers through the celotex to the wall then stapled TXL silver insulation to the batten then another batten then foil back plasterboard (duplex) on top
this method meets building regulations for (insulation)and solved the damp problem in the walls.
the floor was asphalt which was cracking up
the floor was removed and we found the original stone flags underneath
the stone was taken up and sand blasted outside the floor level was lowered
insulation was put down with a dpc then underfloor heating was put on top of the insulation
then concreted
then we laid the flag stones back onto the concrete floor .
we also had to replace door frames

you can't cover up damp wall with normal plasterboard
it will always come through and in some cases cause mould to grow on the back of the boards
most old houses were plaster with lime this was breathable and allowed moisture to move through the wall (warm inside to cold outside) painting the walls with plastic based paints (inside or out) seals the wall and will not let it breath, gypsum plasters seal the wall and suck up damp

you have to use all lime plaster and lime washes (the old way) or

seal the inside walls with waterproof render then use gypsum plaster or boards then plastic paints and wall papers (new way)

hope it helps
green thing

[Alison]

Tanking was what came to mind for me too but as said more info is needed. Basically the DPC issue is a bit irrelevant if it's a basement as it would be below a DPC anyway (they tend to be about 6" above ground level). You'd be best getting somebody to have a look at it and if you want a bit more help then you can always post what they say on here but basements often have damp problems due to being in permanent contact with the ground (especially if you have a high water table) and poor ventilation.

[Caro]

Hi guys,

Thanks for the input. I've never liked the idea of tanking, as it always seemed to me that you were just sealing the problem in. not that I actually know anything about it

There is no DPC at all, and I think the plasterboard was just dot-dabbed to the walls, then taped & plastered.

Green thing, you mention that insulation was put down with a DPC ... was this under the level of the original floor, since youn mention the floor was lowered, therefore undrneath the walls?

PS it's the internal walls that are the problem, not the exterior ones, if that makes a difference.

Thanks guys

[zazen999]

Hi

I take it you had visible damp before doing the walls; in which case - did you get anyone to look at it before hand to see what they said?

[pigletwillie]

dont cover the stone with anything as it will naturally breathe. Also use only lime mortar as that also wicks away water whereas cement does not. Most old house dont suffer from damp until its trapped by paint or modern building materials. The more you can ventilate the better

[Alison]

If it's just internal walls then it's almost certainly a ventilation thing.

[bearded bloke]

If the problem is restricted to an internal wall then you may well be able to have a damp proof course injected chemically at floor level & possibly where it abuts the external wall

[Hilary B]

It's good to see so much of the proper advice (ventilation, let it breathe, lime finishes not cement and waterproofing, etc).
If you tank the basement you probably WILL drive the dampness up, and if there is a timber floor just above, look out for wet rot or dry rot, as well as increased likelihood of woodworm.
OH is a Chartered Surveyor, and we look at a LOT of older houses. Many damp problems are a matter of poor maintenance (rainwater goods that leak/drip/overflow, flowerbeds over DPC, etc) 99% of the rest are due to waterproof finishes and/or lack of ventilation.
Injected DPC is intended for brick walls, and are of very limited use in stone (and not a lot better in really old bricks either).

[Caro]

Everyone, thank you so much for your replies. I can now start suggesting (gently) possible solutions to OH

[Madasafish]

We have an 1820 stone house. We had a DPC injected into our 2 foot wide walls 28 years ago.
No damp now.

[green thing]

Hi caro

Green thing, you mention that insulation was put down with a DPC ... was this under the level of the original floor, since you mention the floor was lowered, therefore underneath the walls?

there was enough wall under the floor level to dig down in this case
I would not recommend digging down past the bottom of the walls or under.
you can do it if you under pin (putting concrete under the walls).
you can find out if there is enough wall under ground by digging a trial hole next to the wall to
see how far your walls go under ground .
it's a good idea to check your guttering down pipes and grids when it chucking it down to see if the water is going where it's supposed to
Our neighbours damp problem it was caused by her neighbours rain water gully backing up and overflowing in heavy rain , it took two minutes to solve by putting on a pair of rubber gloves and putting your down the drain and cleaning out the trap on the gully pot.
I've also had soil stacks leaking at the base and old lead water mains leaking causing damp problems in the past .

green thing