Fixing celotex to brick directly
Fixing celotex to brick directly
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xyz123

Original Poster:

1,092 posts

150 months

Tuesday
quotequote all
Hi, hope you all had a good Christmas.

I have an awkward small job to do. We have an air brick that is redundant in pantry. It makes the whole area freezing cold with constant draught. I need to close the vents so I was thinking of just cutting a celotex board to the right size and stick to the brick. Due to very less space, I can't get any tools in there to put a batton or to drill anything. Will a grab adhesive work between celotex and brick? Or do I need to get any other special adhesive.

Other option is to just get some mortar and individually fill the air brick holes. I can get one in tube to avoid faffing around with cement for such small quantity? I guess expanding foam can also work.

Thanks for reading


Car bon

5,108 posts

85 months

Tuesday
quotequote all
If it's not visible, I'd just use expanding foam.

If you want to use Celotex, then expanding foam is the perfect adhesive for it anyway.

paddy1970

1,225 posts

130 months

Tuesday
quotequote all
If the air brick is genuinely redundant, the simplest and tidiest solution is to cut a piece of PIR/Celotex to size and bond it directly to the brick using a decent high-grab hybrid adhesive (CT1, Sticks Like, etc.), as the board is very light and this works fine on clean, dry brick; apply the adhesive in thick beads to cope with the uneven surface and seal the edges to stop draughts. Tube mortar is not ideal as it is slow, messy and not really designed to block airflow, and expanding foam will work but is harder to control, difficult to reverse and can look untidy. Just make sure the vent is not serving a suspended floor or appliance before blocking it.

fooman

626 posts

85 months

Tuesday
quotequote all
Car bon said:
If it's not visible, I'd just use expanding foam.

If you want to use Celotex, then expanding foam is the perfect adhesive for it anyway.
Using expanding foam (low expansion if you can get it) would also be a good way to fix cellotex in place and seal. A bit more stable than a blob of foam by itself.

PRO5T

6,663 posts

46 months

Tuesday
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Look for anyone building local and go borrow a bucket of mortar for a fiver or a round of bacon butties for the lads!

If anyone uses the search function to find out how to fix PIR to brick/block properly, you buy plastic mushroom style plugs that drill through into the blockwork and hammer home a plastic expansion part.


JoshSm

2,630 posts

58 months

Tuesday
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The adhesive expanding foam for plasterboard is ideal for sticking sheets of anything to a wall, it's what it's designed for and it won't easily come off. You can build blockwork with it too.

The mechanical fixings are an alternative but not better.

Personally for filling an airbrick I'd grab one of my foam guns, fill the individual holes with small squirts, then cut any excess off flush once it hardened. That worked fine the times I did it. You don't need to go mad filling it, you just want to block it off.