We had our loft insulated about 25 years ago along with cavity wall insulation under some scheme or another. I forget what thickness the loft insulation was but it protruded above the 4X2 joists. Possibly 6 or 8”? Anyway, not long after that I boarded out my loft which required compressing whatever insulation I did have, down to the thickness of the joists - 4”. We did this because we needed to use the loft as a storage area.
Will I have been getting near enough the same thermal qualities with it squished to 4” compared to what it was? It’s bloody cold up there and we do get frost settling on the tiles when cold (apart from the area directly above the boiler which is fitted in the loft) - it was certainly cold enough one year to freeze the unlagged portion of pipe going to the cold water storage tank when we had one. If not, will it be worth the expense of unboarding the loft, adding extenders, more insulation and then reboarding or will 4” of insulation, 19mm ply plus a layer of 30 years of 'stuff' be enough?
Will I have been getting near enough the same thermal qualities with it squished to 4” compared to what it was? It’s bloody cold up there and we do get frost settling on the tiles when cold (apart from the area directly above the boiler which is fitted in the loft) - it was certainly cold enough one year to freeze the unlagged portion of pipe going to the cold water storage tank when we had one. If not, will it be worth the expense of unboarding the loft, adding extenders, more insulation and then reboarding or will 4” of insulation, 19mm ply plus a layer of 30 years of 'stuff' be enough?