I have a metal garage roof that gets very bad condensation in the winter,If I fix polystyrene to the underside will this stop condensation,If so do I have to leave an air gap between the metal and the polystyrene.
I cannot afford to replace the roof which is in good condition.
thier is a anti condensation paint on the market that cures this problem
j mitchell, November 2009
Difficult to stop without cost.
I search the net and nobody has come up with an miracle cheap cure.
Peccavi's suggestion is ok but will need the air vent each end to outside to allow airflow.An alternative is polyfoam spray www.sprayfoaminsulation.co.uk
Check out at local builders merchant see if they have rubberised paint it may reduce it but not stop it Try fixing the vents first to allow a continuous air flow see if that makes a difference then go for paint or poly.
BB, November 2009
If you leave an air gap between the polystyrene and the metal roof then warm wet air may enter the gap between and condense out unseen. No gap / small gap will be best I think.
If you keep a car in the garage let it cool down for an hour or so before putting it to bed at night.
