Hello,

I have 4" roof joists and 4" of insulation in my loft and I want to make it
either 8" or 10" of insulation. Some of the loft is floor-boarded and I'd
like to floor more for storage etc, do I lay the extra 4" of insulation
in-between the joists and squeeze it in with the loft board or is it not
possible to board over the extra thick insulation?

TIA,

Darren

"Darren Cooper" wrote in message
...
Hello,

I have 4" roof joists and 4" of insulation in my loft and I want to make
it
either 8" or 10" of insulation. Some of the loft is floor-boarded and I'd
like to floor more for storage etc, do I lay the extra 4" of insulation
in-between the joists and squeeze it in with the loft board or is it not
possible to board over the extra thick insulation?

TIA,

Darren


Compressing the insulation will negate its effect.
If you want to board over an area, start by laying a second layer of 4"
joists at right angles to the exisitng ones and fill the gaps with the extra
insulation. Then lay the boards on top.

Bob

"Darren Cooper" wrote in message
...
Hello,

I have 4" roof joists and 4" of insulation in my loft and I want to make
it either 8" or 10" of insulation. Some of the loft is floor-boarded and
I'd like to floor more for storage etc, do I lay the extra 4" of
insulation in-between the joists and squeeze it in with the loft board or
is it not possible to board over the extra thick insulation?

Darren

There is stiff high performing foam insulation board about 2" thick. Use
this over the joists and have the chipboard over. The screws run through
both. Have this in the parts of the loft where boarding is needed. The
other parts, add Rockwool until 300 to 400mm deep.

Make sure all the holes into the loft are sealed. Pipes and wires. Fit an
insulated loft hatch that is sealed.

Darren Cooper wrote:

Hello,

I have 4" roof joists and 4" of insulation in my loft and I want to make it
either 8" or 10" of insulation. Some of the loft is floor-boarded and I'd
like to floor more for storage etc, do I lay the extra 4" of insulation
in-between the joists and squeeze it in with the loft board or is it not
possible to board over the extra thick insulation?

Compressing the stuff will lose much of the extra insulation properties.

An easy way to add more without having to tit about making the joists
deeper (or laying cross joists etc) is to lift the boards, lay a ridgid
board insulation[1] onto the joists, then lay the boards back on top.
Screw right through the insulation into the joists below to fix the
boards in place.

[1] a foil backed PIR foam like celotex or one of the many cheaper
equivilent makes - you won't need 4" of the stuff however since it
insulates much better than rock/iso wool. If you wanted a cheaper
alternative, then jablite would probably do as well - although you would
need to take care to keep any cables away from it.


--
Cheers,

John.

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