I have a flat with a small cupboard which has 2 wall which form part
of the outside wall that is to say they are in the corner of the
building. The one wall has dampness below a window which seems to be
getting worse. I accept and understand that in all dampness cases the
source needs to be found 1st and treated, but the outside wall looks
fine and as the dampness is not major i would welcome a cost effective
and easy way to prevent/slow down the effects. I heard about a paint
which if applied inside will help, also is there something i could
paint outside to protect the brickwork against dampness. I WELCOME
ANY COMMENTS AND THANK YOU IN ADVANCE FOR YOUR ADVICE.

Rigger wrote:
I have a flat with a small cupboard which has 2 wall which form part
of the outside wall that is to say they are in the corner of the
building. The one wall has dampness below a window which seems to be
getting worse. I accept and understand that in all dampness cases the
source needs to be found 1st and treated, but the outside wall looks
fine and as the dampness is not major i would welcome a cost effective
and easy way to prevent/slow down the effects. I heard about a paint
which if applied inside will help, also is there something i could
paint outside to protect the brickwork against dampness. I WELCOME
ANY COMMENTS AND THANK YOU IN ADVANCE FOR YOUR ADVICE.


Any oil based paint on the inside might help a little (no point in
buying anything special) but it sounds like you may have a problem with
the window sill. Either it's porous or the joint between sill and wall
needs sealing

On 16 Aug, 12:04, Rigger wrote:
I have a flat with a small cupboard which has 2 wall which form part
of the outside wall that is to say they are in the corner of the
building. The one wall has dampness below a window which seems to be
getting worse. I accept and understand that in all dampness cases the
source needs to be found 1st and treated, but the outside wall looks
fine and as the dampness is not major i would welcome a cost effective
and easy way to prevent/slow down the effects. I heard about a paint
which if applied inside will help, also is there something i could
paint outside to protect the brickwork against dampness. I WELCOME
ANY COMMENTS AND THANK YOU IN ADVANCE FOR YOUR ADVICE.

Dear Rigger
As i understand it you have two sources of dampness
One under a sill. All the subsequent posts are right. I would also add
that by now the plaster may well be hygroscopic and thus you may need
to replace it in a suitable material such as a sand:cement render. To
test for hygrocopicity you can get simple chemical tests for salts or
you can measure the dampness and compare it to the relative humidity
in non-rainy weather and see if there is a correlation. It would be
quicker just to replaster!
I personally would fix the cause and wait and see if it went and only
after fixing the cause (drip groove, negative slope on sub sill, joint
opening up etc etc) and it still being wet would I conclude that it
was hygroscopic and replaster.
The cupboard sounds like a classic case of condensation but with the
absence of data I cannot advise. There are only four categories of
dampness in buildings. Rising - lateral penetration - pipe leaks - and
condenstion

Chris