extractor fan in an air-brick

coffeehound

Davesnave wrote: »

I can see advantages of having a fan not only in solving this problem, but also in compensating for the air bricks lost in the extension. If we add in the possibility of the OP being in a moderate to high radon area (about half the country) the OP might well consider the modest cost worthwhile.

I was originally thinking the OP's house was rented, but given (s)he owns it, a PIV fan would be ideal here. Easy-ish to install and due to running continuously would prevent smoke entering round the clock. It would push air from the house interior through the floor gaps and out of the airbricks thus improving the ventilation of the underfloor timbers at the same time. Would also allow extract fans to run without pulling the smoke in.

martinsurrey

before we get all high tech about it OP how about you get and try these first.

airbrick cover
Wont offer any positive ventilation, but will stop them balancing fags on it.

Also, consider installing a small shelf on the wall, away from your vents and ask them to use that for smokes.

installing a fan in a difficult to access area is asking for trouble, but is a last ditch solution.