Have 1930's house with solid brick walls - rendered on outside. Extension in the 80's blocked up air bricks at back. Need to add more to ther walls I think to improve sub-floor vent.
Should airbrick sit under or above DPC?
Is same process for cavisty walls as illustrated on this site?
Do I need a wall sleeve, as for cavity walls, for solid walls? The airbricks in the walll do not seem to have these.
Any help welcome. Thanks