I am still in pondering mode about my loft insulation.

After a bit of looking around I see that knauf do a type of insulation
that looks pretty neat. Its called space blanket
(http://www.space-blanket.co.uk).

The thing that I like about that is that I could lift up the insulation in
the future for wiring etc, and it's all enclosed, so there shouldn't be so
much dust flying around.

However I have 2 questions.

1) My joist height is 4 inches (100 mm), but their product only sells in
150mm and 200mm. If I installed the 150mm and later boarded on top of it,
(effectively making 150mm into 100mm), would that simply mean that the
insulation would act as if it were 100mm, or would it be less effective as
there wouldn't be as much air to trap the cold.

2) The space _between_ my joists varies ever so slightly, it appears to be
around 400mm. All of the loft insulation that I have seen sells in 370mm
width (they must assume 400mm joist centres). Has anyone else seen this
before and got any advice on what to do?

Thanks

Dean

Sir

What I did was to put 2 layer down, one in the joists, one over the top, I have 400mm, which is OTT, but the ice don't melt off my roof. The normal fibre
stuff has a bit of give in it with sizes, so 370mm and 400 are near enough to be OK.

The bit I boarded over has "cavity bats" as insulation, as these are more solid and can be cut to shape and size, using a bread knife. If I insulated under
the boarded floor again, I would use celotex, which is expensve, but easy to cut to the right shape, and much nicer to work with than fibre.

Rick

On Sat, 29 Nov 2003 12:11:15 +0000, Dean Richard Benson wrote:
I am still in pondering mode about my loft insulation.

After a bit of looking around I see that knauf do a type of insulation
that looks pretty neat. Its called space blanket
(http://www.space-blanket.co.uk).

The thing that I like about that is that I could lift up the insulation in
the future for wiring etc, and it's all enclosed, so there shouldn't be so
much dust flying around.

However I have 2 questions.

1) My joist height is 4 inches (100 mm), but their product only sells in
150mm and 200mm. If I installed the 150mm and later boarded on top of it,
(effectively making 150mm into 100mm), would that simply mean that the
insulation would act as if it were 100mm, or would it be less effective as
there wouldn't be as much air to trap the cold.

2) The space _between_ my joists varies ever so slightly, it appears to be
around 400mm. All of the loft insulation that I have seen sells in 370mm
width (they must assume 400mm joist centres). Has anyone else seen this
before and got any advice on what to do?

Thanks

Dean

Years ago I insulated my loft with polystyrene bats (non flammable type)
then covered them with ply, I think you can get them in 8' x 4' x 3" sheets,
you could then cut them to width and they would be easy to lift.

Mike P.