Sealing around wall vents and fitting one-way valves.

Yorky

Is rigid insulation suitable for sealing around where extractor fan ducts vent at the wall vents? Are there any long-term problems associated with this?

Also, has anyone any knowledge of one way valves which can be fitted to the inside of an extractor fan?They have flaps which are spring loaded and open when the fan is switched on and close when it is off preventing backdrafts.

Hoagy

Expanding foam is usually used around a duct where it goes through the wall, is that what you mean by rigid insulation?

The anti backdraft device is called a gravity shutter; it goes on the outside end of the duct.

Yorky

No, this is actually rigid sheets of insulation cut into pieces and stuffed around the duct to seal the cavity as the brick vent is one brick wide and 2 bricks high whereas the duct is only 100mm.

The actual valve is fitted to the rear of the fan, looking from the inside the other side of the actual fan blades, on the neck of the thing.

FrankGrimes

I bought 2 anti-backdraft shutters last year and misplaced one which I now need but can't remember where I got them and am finding them hard to track down. If you find them would appreciate if you let me know where, good luck.