HI,

I have just discovered my house has had an air brick added that opens
the cavity to the outside and the underfloor void. This is not how the
others are fitted and it looks like a bodge rather than planed.

I'm wanting to block the hole into the cavity with urethane foam so it
is warmer. Am i ok doing this?

What other provision for venting the underfloor void is there?

Usually they're designed with cross ventilation to ensure rot doesn't
occur in the floor joists.

I would be cautious about closing off existing ventilation of any
sort, unless I could see why it had originally been installed, and why
it was now redundant.

wrote:
What other provision for venting the underfloor void is there?

Usually they're designed with cross ventilation to ensure rot doesn't
occur in the floor joists.

I would be cautious about closing off existing ventilation of any
sort, unless I could see why it had originally been installed, and why
it was now redundant.

He's not closing ventilation off to the floor, he wants to close of the
ventilation into the cavity, IE sleeve the vent, like the others are
sleeved.


To the OP, the others are probably sleeved, usually with slate, but also
with bitumen DPC depending when it was built, this one has probably been
forgotten about by a clumsy bricky.
Block it off with foam or fibreglass, taking care not to allow foam to
extrude through the vent to outside as it looks hideous, and not to block
the underfloor ventilation.


HTH

--
Phil L
RSRL Tipster Of The Year 2008

He's not closing ventilation off to the floor, he wants to close of the
ventilation into the cavity, IE sleeve the vent, like the others are
sleeved.

That's right. I'll be closing the ventilation to the cavity. I hope
that does not cause damp. I think i'll use fiberglass - so i can
reverse it easily if i have any problems.

Cheers

Phil

On 25 Sep, 10:14, " wrote:
What other provision for venting the underfloor void is there?

Usually they're designed with cross ventilation to ensure rot doesn't
occur in the floor joists.

There are too few airbricks i fear. but absolutely no sign of rot -
timbers completely sound. (we have a 2-3 foot crawl space that I have
investigated. There used to be 4. Two each side of the 10m square
bungalow. One has now been blocked up because of an extention. I'm
looking into getting another two added along a third side of the
bungalow, but these will need to go down first as the ground level is
high (but not over the DPC)

Another thought was to put some electric fans under the floor for
active ventilation - any thoughts on this idea would also be welcome
(I'm contemplating this because we have just found mould on some of
the kids toys and on the underside of our matress - urgen action is
required!)

Cheers for your input.

Phil