I’ve been told that the ground under my house is damp and that I should get a polythene moisture barrier installed so that the house is drier and easier to heat. Can I do this myself?
Filed under Frequently Asked Questions.
May 8th, 2011
I’ve been told that the ground under my house is damp and that I should get a polythene moisture barrier installed so that the house is drier and easier to heat. Can I do this myself?
Editor, May 8th, 2011 on 10:04 pm
First check your underfloor ventilation. If you have an open underfloor or “hit and miss” battens, there is probably plenty of airflow and little value in installing a moisture barrier. If your have a concrete ring foundation or little ventilation, find out why your underfloor is damp and if possible deal with any plumbing or drainage problems first (get these checked by a professional).
If there is nothing you can do (without calling in the cavalry) because you are in a low lying valley or the house is cut into a hillside, a polythene moisture barrier can help keep your house dry and warm inside. In some cases it can make a substantial difference to the moisture levels inside the house.
Polythene sheeting is available from hardware stores. Purchase the thickest grade (250 micron is best) and cut it into approximately 2 metre strips to lay between the piles, cutting slits along one side to fit around piles. Slits need to be taped up with polythene tape around the piles, and the overlaps between neighbouring strips also need to be taped. Weedmat pegs (available at hardware stores or garden shops) can be used to peg down the polythene at regular intervals (every 2 metres or so), rocks or heavy objects will also do.