Dampness to window / door reveals caused by breakdown of DPC joint

mmgaa · 27-01-2010 10:31AM #1

I constructed a 2 storey house (2,450sqft) about 3 years ago.
I employed blocklayer, plastering etc subcontractors.
I supervised the project myself being a Q.S.
An ongoing problem I have is that about 7 no. windows have dampness on internal reveals which spreads to the wall also.
This has caused the paint to flake etc.
I have been trying to contact Damp Proofing Contractors to call to property to provide estimate / method to complete repairs etc.
I feel its a breakdown of the DPC joint at window head (possibly the DPC at head of window was pushed back in behind window when plastering was being completed).
Plastering & window contractor are not accepting responsibilty.

Im just wondering if there is a DPC injection subcontractor available or has anyone info or experience on how to rectify this ongoing problem.
Possibly a good tradesman has experience of such a problem.

Im based in Wexford.

Any info would be greatly appreciated.

gears · 27-01-2010 12:35PM

There could be many reasons for this dampness.
If there are windows above those affected it could be from a poorely installed dpc under a cill of the windows above with water moving down the cavity finally stopping at the window frame.

The moisture causing the dampness could be weeping in around the window frame at the junction between it and the plaster if the dpc is not properly in place.

I could go on and on but I think it will all be guess work until you do some investigation by completely removing the reveal around at least one window and see what you have, the problem could be very obvious.

beyondpassive · 27-01-2010 01:03PM

Are the subject windows highly exposed to previling winds, are you exposed to the sea?
You should also try to rule out condensation damage, if you have a good timber frame then the plaster to the reveals is the coldest surface in the house and water vapour ( each house produces about 10 litres per day) will condense, if the surface temp is below dew point. So if the house is heated up to 20 degrees and has 70% humidity, then if the reveal surface can't get over 13%, the vapour will condense there unless there is high ventilation rates.

mmgaa · 27-01-2010 01:23PM

Thanks for responses.

The windows are on a 1st floor bedroom for example and its a block construction.
I feel myself that the DPC was pushed in over head of window frame while plastering was being completed. Therefore allowing the water to travel along head of window frame and escape / soak into inside face of wall / reveal.

I would be grateful of any further suggested remedial works to carry out.

Thanks a million.

Dampness to window / door reveals caused by breakdown of DPC joint

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