Hi, I need to put a couple of vents in a rubble wall to improve sub-floor ventilation. My house is an old cottage with a damp soil subfloor. I have no rising damp, but I want to dry it out to get rid of the damp smell and to prevent any issues with rot - I've just got rid of rotten joist end etc. My plan was to core drill a couple of 125mm holes (separated by about
3 metres), sleeve the holes using underground waste pipe of the right diameter, and chip out enough of the stone on the outside to let me fit airbricks and make it look presentable. My problems are - this is a supporting wall - am I likely to destabilise it by drilling in this way - and, I have never used a core drill before - I'd be grateful for any advice or guidelines. Also grateful for any general advice about this topic.Thanks,
R.