I recently posted this picture of an old core-drilled hole for an extractor fan through the thick stone wall of my flat; it has been done from the outside inwards and is too high, slicing off the bottom of the ceiling joists.
I’m now putting everything back together and I’d really like to line the hole with a pipe, so that the moisture doesn’t dampen the wall. But I can’t slide a solid pipe in from the inside as the ceiling is in the way. I could do it from the outside by removing the air brick, but that would involve chiselling out the mortar from the top of a ladder.
I could use a length of flexible duct but I’d prefer not to if possible, so I have been considering whether I can make something that will roll up for insertion and spring into place. If I had something like a fizzy drink bottle, but >100mm diameter and 800mm long, I could cut it lengthways, roll it up tight, slide it in, and then it would pop open. Any less crazy suggestions anyone???
