Hello all – I hope you can help, and sorry for the essay!
I have some damp issues in a half-brick thick lean-to. I think it is a combination of condensation and some penetrative damp and would like your opinions on what I think are possible solutions – I’m no expert by the way.
Firstly, the condensation. Within a month of moving into my new house I noticed black mould growth in the corners of the lean-to. To tackle this I turned up the heating in the room slightly and locked the windows in a slightly open position to improve temperature and airflow. So far, this has appeared to mitigate things somewhat – but does anyone think perhaps installing some airbricks, maybe high up, would be a better long term solution than having the windows permanently open?
Secondly, possible penetrative damp. On the wall of the lean-to that faces the garden, paint and plaster has blistered and fallen off along the length of the wall at around 50cm high – almost like a tide-mark (with some mould growth as well). I do not believe that this has been caused by condensation alone. This is because the garden patio, which runs right up to the lean-to wall, is a higher level than the floor in the lean-to (which also has some damp patches near the wall). I think that this is the primary source of the damp issues on this wall. Rather than some sort of DPC, I thought that digging a French drain around the external walls of the lean-to, thus preventing water lapping up against this wall, would reduce most of the damp in this wall – does anyone agree/disagree?
I can upload photos if anyone feels this is necessary
Huge thanks to anyone’s input – as I said above I am no expert but I have done some research.