Expanding foam to seal vent.

[wedge69]

In our hallway we have a vent to the outside. This was necessary when the house was built because of the type of boiler that was in there. With our new boiler the plumber said the vent is no longer necessary and we should close up the hole, which s good because it's freezing in the winter!

I am not a very good DIYer so was looking for a simple way to do this. I thought about using expanding foam in the void, and then a bit of board on the inside. The vent cover would still be visible on the outside of the house, but this would look better than the mess I would make if I tried to rip it out and brick it up, I would probably destroy the wall.

If I do use expanding foam, is it water proof? I.e if any rain splashes into the vent, is it going to be ok, or should I use some other material?

 

[big-all]

expanding foam is great fully waterproof and gap filling
the trouble is it expands about 100 times its volume
so its likley if your not carefull to spew out the gaps on the vent
if you cover the vent with cardboard on the back it should be ok spray on a half inch covering and just leave it then take it from there

 

[wedge69]

Ha ha, didn't realise it expanded that much!

If I put cardboard in first, won't that stand a chance of getting wet?

job for this weekend!