The other damp problem which has appeared is on the ground floor, around the walls of the front of the house.
The two ‘damp experts’ who came diagnosed rising damp of up to 1 metre in places. The house is brick but has been very well insulated. One side wall is covered in plasterboard with insulation behind it. The second ‘expert’ told me, with his clever measuring tool, that the damp was all the way along this wall. On the other side there is a wall covered in decorative brick slips, and the damp man said the damp was behind these too. At the front of the house whose wall isnt insulated the damp is visible as it is causing the paint to peel and a small amount of mould to appear. It’s not wet to the touch but it feels a bit cold.
Firstly I want to know what the real risks of rising damp are to the construction of the house (I’m aware of health risks and damage to aesthetic etc). Could I just leave the plasterboard in place and not worry about it? What could I do to alleviate it at the front of the house?
According to RICS, I went to a demonstration of various bricks and some would absorb moisture and it would rise up the brick to the one above etc. I also worked on the regents canal basin where water was definitely rising up the wall.
It does not of course mean that is the source of OP’s damp which sounds like it could be interstitial damp.
Hence why I used the word largely. Water travels and will be absorbed but it doesn’t magically rise a metre up walls unless your floating. It’s a term that’s so mis used it’s become pointless/misleading.
There’s normally a root cause whatever word you give to the damp.
The only way to actually determine water content is to take a sample of X, weigh it, thoroughly dry it in a kiln, re-weigh it and assume the difference is moisture loss.
In a really old house like ours, damp is inevitable. There are no foundations and no damp-proof layer. What we’ve done is have the walls lined with a lot of insulation PLUS a ventilated air gap between the insulation layer and the outside wall. Seems to work well…
They have uses but … They measure conductivity not water - they are set for wood - and you can’t change the cheap ones - and they can be fooled by any number of things - especially salts from old damp issues. They are beloved by “damp experts” because your almost guaranteed to find “damp” in older houses with them.
