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Damp Proofing

Damp patch

Hi we have recently renovated a 3 bed house. We fisnished work at end of nov and the house has been empty since then. We have now notice a damp patch approx 18" in size in the interior of an exterior wall up the stairs, about 4ft from the ceiling, we havnt had any heating on since nov due to problems with it could this be the cause or could we have a penetrating damp problem.

Ps There are no down pipes, as its a gable end wall and the pipes are at each end of the outside wall and I would say the patch is in the middle of it.
We do however have a leak around the window we noticed a couple of weeks ago thought it was the seal around the window as we could see daylight when the plaster was off internaly so we resealed it and its still leaking when we have a downpour.

2 Answers from MyBuilder Damp Proofing Specialists

Hi there
if there is no visible signs of distress on the exterior then it should not be penetrating but with out looking at this problem it is difficult to advise
would need to see if there is a down pipe or such letting the water in or could be condensation but if it is, its in a strange area.


Answered 17th Jan 2013

Has there been a historic penetration dampness issue? Direct rain penetration through walls can results in an accumulation of sulphate on the internal face of walls. The penetration may be cured but the salt may still be present in the plaster.

Sulphate salt is a hygroscopic salt. These types of salts can absorb water directly from the air to such an extent that the wall can become visibly wet. This dampness effect is entirely separate from that caused by capillary action and is usually referred to as “hygroscopic” dampness.

If the property has high humidity problems too, this can exacerbate the effect.


Answered 17th Jan 2013

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