Morning,
I have a thatched property with very old (but generally good condition) lath and plaster ceilings in the bedrooms.
An insulation contractor has successfully got the council to agree to installing loft insulation for free (the loft has never previously had any insulation).
But they want to use blown fibre instead of blanket insulation. I can see three problems with this:
1. There are small patches where the lath and plaster ceiling will need repair, and over time maybe more. Although the repairs would be done from below, I suspect that blown fibre insulation would have to be removed from the area which would be like trying to dig a hole in loose sand.
2. The joists are quite narrow - around 3" and very uneven - and its my understanding that the blown fibre insulation would cover them and make them invisible. Hence, when I go up into the loft afterwards, I would put my weight on movable boards but these would rest on the insulation which would itself rest on the ceiling, and that could break the ceiling.
3. Even without the above, I don't know if the weight of the blown fibre insulation itself could break the ceiling, if not immediately then over time - the contractor says it wouldn't, but I don't fully trust them.
Does anyone have any views on these, please ?
(I am thinking of instead putting in glass fibre blanket insulation myself, it would only cost around £150 plus a day or so work).
Thankyou.
I have a thatched property with very old (but generally good condition) lath and plaster ceilings in the bedrooms.
An insulation contractor has successfully got the council to agree to installing loft insulation for free (the loft has never previously had any insulation).
But they want to use blown fibre instead of blanket insulation. I can see three problems with this:
1. There are small patches where the lath and plaster ceiling will need repair, and over time maybe more. Although the repairs would be done from below, I suspect that blown fibre insulation would have to be removed from the area which would be like trying to dig a hole in loose sand.
2. The joists are quite narrow - around 3" and very uneven - and its my understanding that the blown fibre insulation would cover them and make them invisible. Hence, when I go up into the loft afterwards, I would put my weight on movable boards but these would rest on the insulation which would itself rest on the ceiling, and that could break the ceiling.
3. Even without the above, I don't know if the weight of the blown fibre insulation itself could break the ceiling, if not immediately then over time - the contractor says it wouldn't, but I don't fully trust them.
Does anyone have any views on these, please ?
(I am thinking of instead putting in glass fibre blanket insulation myself, it would only cost around £150 plus a day or so work).
Thankyou.
The weight on boards for access around the loft would be supported by the joists which support the ceiling. All insulation in roof spaces at joist level covers the joists nowadays because 300mm thickness of mineral wool quilt is the recommended minimum thickness for thermal insulation.