Hi all,

Ive just joined and dabble in a bit of DIY every now and then.

I live in a 1930 terrace house and have always had patches of damp throughout the house (no cavity wall). I've managed to keep on top of it besides one part of the house - the small frontroom bay window. In other areas of the house I've cleaned it up, given it ventillation, painted over with paint stop and painted on top.

For some reason below the (unoccupied) front room bay window still attracts a huge amount of condensation. Its so damp the paint comes off in your hand as you wipe the wall. Nails in the shirkingboard are begining to show rust. Not sure if the house has any damp proofing in the concrete floor. But the outside wall has an engineering brick layer (the previous's owners answer to the question).

Any advice? A builder recemmended taking off all the plaster, treating it with chemicals and paster new board a 10mm from the brick. Quote came in OK. but could be better. - Not sure if this will really solve the problem though. Shouldn't the damp proof be checked?

Would it be worth lowering the outside level of the garden to help drainage.

Next door have installed their own damp proofing and lowered the garden.

Any help or pointer would be helpful.
Cheers.
Paul

See attached pic to see what I mean

btw the pictures are taken after a clean. Its hard to keep on top of the mould.

heeelllooo and welcome grimsbyinneed

your damp proof course [dpc]should be below floor level in turn your path should be 6" below the dpc
with the underfloor void if you have one ventilated by a minimum 2 vents

_________________
we are all ------------------still learning

Thanks big all... I can't seem to see any dpc and the outside garden level is only a brick level lower than the inside wall.

Do you recommend..
1) installing new dpc myself?
2) lowing the garden level floor?
3) add a vent - there are no vents at this moment in time but won't this make it really drafty??

Suggestions from others:
1) chemically treat it to remove the mould.
2) replaster the walls with new boarding 10mm from the brick?

Cheers
Paul

you need to introduce a gully to lower the the path below the dpc
assuming its a wooden floor you need to expose the vents as well

_________________
we are all ------------------still learning

Its a concreate floor.. All of the ground floor rooms have been concreted, I assume to cover up a previous problem.

Can I forget about vents for a concrete floor then? Its always a bit more drafty around the bay window area anyway. I guess this was due to bad workship too?

Your DPC is probably behind the thick course of bricks 3 inches from the path.

Don't pay any one to do anything until you have had a damp company to survey it and even then insist that they offer an insurance backed guarantee as part of any contract you sign.


If you are not keen on what they offer, I would arrange for a DPC injection (£ 400 ish) for the bay. I would then strip back all the plaster in the bay and let the whole thin dry out. Cut back plants which shade it and if you are able, lower that path by a few inches.

When the inside is completely dry, either dry line the wall using a metal frame lining system and vapourcheck board or try the new foam drywall adhesive which prevents thermal bridging and would reduce condensation.

Essentially, either pay high for quality or problem solve yourself, starting with the easy and cheap remedies to see if they can save you a fortune.

Thanks jozeffo...

I do have a slate DPC, but it looks to be failing outside the bay window.

I got these guys to give me a quote Spam removed. its wont stop the condensation, but its guaranteed to stop rising dam for life.. Its £150 a meter, but it will stop the problem. For the bay window it will cost around £500. Then I'm thinking of ripping off the paster, add new plasterboard 10mm from the wall, with a foil back. hopefully stopping the condensation problem.

Otherwise I'm thinking of injecting the walls with something like this: Spam removed
Then adding plaster board with a foil back 10mm from the wall again. This option could save me around £300.

Paul

Avoid the damp company because they do not appear to offer an insurance backed guarantee which means their guarantee is worth nothing if they fold the company.

The DPC cream I have never used but it is BBA approved which says alot, although you may find it cheaper to try another supplier:-

http://www.concrete-sealants.co.uk/Buil ... e.tpl.html

The kit seems very expensive.

If you do strip the plaster and reboard, make sure you either use foam adhesive or metal lining to prevent moisture and cold bridging the gap.

Thanks again Jozeffo. I've decided to go with your option.

I bought some DPC cream, BBA approved just over £11 a tube via ebay. It can also be installed with a regular sized gun too. That looks easy to install. I've found a video to help direct me. Spam removed

plus this table:

Wall thickness 4½" (110mm) 9” (220mm) 13½"(330mm) 18" (440mm)
Borehole depth 100mm 200mm 310mm 420mm
Borehole diameter 12mm 12mm 12mm 12mm
Application rate per 10mtr 0.9L 1.9L 2.9L 3.9L
Per 380ml Cartridge (Approx) 4.5m 2.25m 1.12m 1m


Taking off the plaster has been much harder than I thought, but it has to be done. Which plasterboard would you recommened to prevent condensation and add installation? Ive found a few brands: Kingspan, Aquaspan, Gyroc but its hard to decide. I want a good one to improve its performance and the problem reoccuring. Looking at the data and costs this option looks good plus it wont be as thick as the others (coming out from the wall less).
Spam removed
This one also has vapour control. It will be about £60 plus VAT for me to do the area required.

To attach the plaster board would you recommend an addistive or wooden frame with gaps at the bottom? If so, how would you attached the wooden frame to the brick work? - normal screw plugs? Would you also use plasterboard screws to attach the plasterboard to the frame?

Paul

This option looks to be saving me around £400 than orginally expected. Alot more work for me, but worth it. Thanks

You seem to have grasped the logic of this stuff well.

I would use regular wallboard on the walls using foam adhesive to prevent thermal bridging and keep the thickness as low as possible. Insulation of this thickness will achieve little. If you have a small gap, the plasterboard will heat up because it is thin and the wall will not because it will not conduct .

You could use Aquapanel thermal (expensive) but otherwise the plasterboard is all much the same unless it has insulation on the back, but that makes it much thicker.

How thick can you go?

I could probably go to a max of 40mm out from the wall (including the wooden frame to attach the plasterboard too - giving a small cavity of 10mm from the wall to the board). The board would then be level with window ledge avoiding any major design fawls. The Thermal board seems to be the best option, preventing further condension and improving installation.

Paul

With the 40mm, you could easily use insulated plasterboard, dot and dabbed to the wall. I think they come in 22 and 28 mm thick so that would suit you fine and condensation would appear elsewhere in the room instead. You don't need to go any further than that.

Dot and dab it is then, with thermal boarding. Cheers. Half way through knocking off the plaster now. Fingers crossed it all goes to plan.

quote="jozeffo"]With the 40mm, you could easily use insulated plasterboard, dot and dabbed to the wall. I think they come in 22 and 28 mm thick so that would suit you fine and condensation would appear elsewhere in the room instead. You don't need to go any further than that.[/quote]

Btw ain't aquapanel for floors??