I have had a constant issue with damp under my suspended floor. No rot as yet but the edge of one of my carpets smells musty and mouldy and this is coming up from the sub floor void. I think that the sub floor ventilation is insufficient. As you can see the airbricks (one of four at the rear of the house) have pretty small holes, and when I removed one of them there was some rubble behind it, not entirely blocking the hole but enough to impede air flow. So I’ve knocked up a prototype grill which I intend to sit on a fillet of concrete and seal around the edges. Is this feasible, or will there be any problems? Also, the front of the house has only two airbricks, one either side of the bay window about 3 metres apart. I feel that another one under the bay would be helpful. Is it doable to knock a hole in the (solid) wall there to open into the sub floor and fit a grille? Any advice would be greatly appreciated.
Why not simply buy and install a new clay airbrick, commonly available and would look better and in keeping with your property. Plus , will last the life of the house. also, check the DPC is not bridged by clay rubble or soil or damaged itself.
Whatever you decide to install? Consider fitting vents which incorporate rodent prevention. Mice for example, can squeeze through holes no bigger than the diameter of a pencil.
That’s a good point re the look of the thing. I just wanted something which would allow as much airflow as possible
Yes, just seen these: https://www.screwfix.com/p/terracotta-air-brick-terracotta-76mm-x-229mm/13873 Doubled up one of top of the other they would be perfect and look to offer very little resistance to airflow. I’ll back them with the mesh to keep out mice etc. Thanks for the suggestions. Any ideas re the feasibility of knocking a hole under the bay for a new airbrick?
I took out the old ones on my 30’s house and fitted the new plastic type plus a few extra ones. Good draught running under the floor now.