Air bricks / cavity

[garethpuk]

Hi,

I've got a total of 6 air bricks to ventilate my downstairs suspended wooden floor, behind the vents the cavity is open and I've noticed the internal wall is noticably colder in the region of the vents. I'm thinking of taking the vents off, sealing the cavity using expanding foam to make sure the cold air coming in goes under the floor and not into the cavity as well. Is this ok to do or could it cause damp issues? Longer term i'm planning on getting cavity insulation and I'm guessing the cavity next to the air vents will need sealed before that goes in anyway?

Cheers,
Gareth.

[titan]

You can use sleeves for that purpose www.hambleside-danelaw.co.uk/products/roofing-ventilation-product-guide04.html

[garethpuk]

Ah, sleeves, why didnt I think of that! Much easier than faffing about with foam.. Thanks for the suggestion.

[biff]

you also need a 160mm upstand up against the inside of the inside skin and running outward to the outside above the vent, you can stick the dpc in the upstand,the sleeve and airbrick come as a kit(adjustable width wise)and can be fitten in mins,it is importand to fit the dpc(apron)
                                                                     biff

[garethpuk]

Looking at the link provided by titan I'm thinking I need HD9350/2 (the bricks are double height) and HD9600CT above to push any drips outside?

I'm sitting here thinking about it and the outside bricks are double height but I think the hole in the internal skin is only single height - no wonder the walls are cold as there must be a fair old draft travelling through the cavity!