A friend is looking to fit a Danville Opti-myst Inset Fire with a marble fireplace. Allowing for the thickness of the fireplace and the plaster on the wall, it'll need about 20-30mm cutting out of the blocks to let the fire sit flush to the surround.
However, the wall (standard cavity wall) is hollow blocks on the inner leaf, so taking this much out will almost certainly take out the whole front face of the block over most of it's area - just leaving the webs sticking out from the rear leaf like piers.
Is this going to be OK over the size of the fire back (about 0.5m wide by 0.6m high), or is it going to seriously weaken the wall ?
If it's not OK, would removing some blocks and rebuilding with thinner solid ones be OK ?
However, the wall (standard cavity wall) is hollow blocks on the inner leaf, so taking this much out will almost certainly take out the whole front face of the block over most of it's area - just leaving the webs sticking out from the rear leaf like piers.
Is this going to be OK over the size of the fire back (about 0.5m wide by 0.6m high), or is it going to seriously weaken the wall ?
If it's not OK, would removing some blocks and rebuilding with thinner solid ones be OK ?
