Joeboy wrote: ↑Fri Jan 10, 2025 1:10 pm
Edit 1hr later the vermiculite is dissolving. Use only in dry areas kids!
Vermiculite will hold upto 4x its weight in water apparently!
We have just ordered some bags of perlite. Your idea may be the perfect solution to insulating a small cloakroom that we have in the corner of our property that used to be the old outhouse, 2 external walls, 1 of which is partly a single skin brick only, where the old doorway was blocked in.
It was not internally insulated when the rest of the house was done, nor was the upstairs bathroom presumably because it would have required ripping out the suite, plumbing and tiling.
This particular room, despite an adequately sized radiator, doesnt really get above 16C. But it does have voids behind the plasterboard and no tiling up to the ceiling.
If it works and doesnt cause damp issues great, the room will have been barely touched and not decreased in size.
If it doesnt work and water tracks across then we end up having to rip it all out and do it again, but would have had to do that to insulate the other way anyway.
My cheapo thermometer stuck to the outside of our bedroom window is reading -14C right now. How accurate it is, i dont know but we are in a valley.
Google seems to think its -10C here, met office -9 and xcw -5C.
Our cop was down to 1.86 when i checked last at 3am, and the outside heatpump sensor (in the ASHP housing) was reading -9 at that point . Its still toasty and warm in the house.
You wouldnt have a clue it was even cold out.