Underfloor Insulation

new_owner

OK.. Back to this again

I am currently (slowly) insulating under my suspended floors. I have bought Black Mountain Hemp Insulation batts and I am doing the work from the cellar, so insulating the cellar celling. (before crawling around the 2 foot crawl space in the other room)

Now I have a air brick that is above the joist height but the the same height as the boards. Now I know I cannot cover with insulation. Can I create a tunnel through the insulation so the air can still get below the joists?

If this is the case is a wire mesh tunnel the best thing? The thinking is the hemp will allow the wood to breath through it. But i can still insulate around it without interfering with air flow.

The plan is to insulate down to the bottom of the joists with hemp and then use tongue and grove fibre board bellow the joist to stop bridging but still allow the whole house to breathe. So I need to get the air from the air brick under the insulation.

Hope this makes sense... All I can find online is "don't cover the air brick" not haw to insulate around one.

One more question..

Now the gaps between the wall that separates the underfloor room areas. Do I have to treat these as you would a air brick?

Thank you