HI, I'm just about to fit some insulation between the 100mm joists of my ground-level suspended floor from underneath via the crawlspace.
I am currently planning on using Rockwool 140mm with a breathable membrane to hold it in place, rather than Celotex, etc.
The floor above has the original floorboards.
My questions are:
1. Will that be suitable considering there won't be a vapour barrier on the warm side of the insulation?
2. Is there any issue using deeper insulation than the floor joists to boost the U-Value?
Advice would be appreciated :-)