loft conversion insulation...

[ToAoB]

Hi - I am going to replace the plasterboard in the bathroom in the loft.

What type of insulation should I use, there is a gap of about 500mm from the party wall (in roof) to where the stud wall is.
There is nowhere to secure the new blanket of insulation unless I put some sort of plywood on the outside of the stud wall so that it can hold the insulation inwards. (hope am making sense here)

Is there any other easier method to do this as getting plywood thro the studs would be a problem.

Would space blanket be OK? I have purchased some 150mm space blankets and hoping this can be used in the walls?

Any advice appreciated.

Thanks

 

[freddiemercurystwin]

Presumably you could get into the void? Why not fit your Rockwool between the studs and hold in place with chicken wire stapled to the back of the studs? Rigid insulation would be better BTW, that could be held in place by friction or a few nails popped into the rear of the studs. If you go the Rockwool route it'd be tricky doing the last bit where you need to leave a hole to climb back into the bathroom but that'd be possible somehow.

 

[wavetrain]

By writing "150mm space blankets", do you mean the very expensive multifoil insulation that BRE tests prove do not have anywhere near the insulation value claimed?

 

[ToAoB]

Presumably you could get into the void? Why not fit your Rockwool between the studs and hold in place with chicken wire stapled to the back of the studs? Rigid insulation would be better BTW, that could be held in place by friction or a few nails popped into the rear of the studs. If you go the Rockwool route it'd be tricky doing the last bit where you need to leave a hole to climb back into the bathroom but that'd be possible somehow.

Thanks - I could go for the polythene board - would the 25mm thickness be ok? This probably would solve a lot of hassles!

 

[ToAoB]

By writing "150mm space blankets", do you mean the very expensive multifoil insulation that BRE tests prove do not have anywhere near the insulation value claimed?

Not effective? Thought they approved by the energy trust or something like that?

Expensive as a single set yes - but Wickes was doing them for buy one get three free....so four for the price of one...so guess this is a good deal?

 

[freddiemercurystwin]

25mm!!!! You wanna be looking at about 100mm! Loft walls need about 130mm to comply these days. Still if all you can afford is 25mm then fill yer boots. Really a bit pointless though.

 

[freddiemercurystwin]

I wasn't suggesting you fit 25mm rigid board at the back to hold your space blankets in place BTW, that'll probably just crumple and break apart as you force the blanket into the void. I was suggesting you use Rigid insulation as a complete alternative not in conjunction with.

 

[wavetrain]

@ ToAoB You have been conned.

google 'multifoil hot-box bre' and read on.

 

[ToAoB]

I wasn't suggesting you fit 25mm rigid board at the back to hold your space blankets in place BTW, that'll probably just crumple and break apart as you force the blanket into the void. I was suggesting you use Rigid insulation as a complete alternative not in conjunction with.

when u say rigid insulation - did you mean by using a board at back and then use rockwool? I thought you meant the Polystyrene sheeting in place of the rockwool. I have some 6mm plywood leftover - that would cover the whole of the stud walls inside the void I could cut it into strips and secure.

Trying to clarify - seem am reading this wrong somewhere

 

[freddiemercurystwin]

Sorry to make things sound a bit confusing, I was suggesting two alternative methods you could use.

1) Use Rockwool between the studs and hold in place with chicken wire or equivalent (plywood if you can get it in there).

2) Use rigid insulation the same thickness as your studs and hold in place with some nails popped into the studs at the back, then when the insulations in position tap the nail heads a little to hold the boards snug against the plasterboard. If you really want it toasty add a layer of 25mm or so to cover the back edges of the studs. Although frankly if the rest of the loft walls/roof is poorly insulated this is overkill.

 

[ToAoB]

Sorry to make things sound a bit confusing, I was suggesting two alternative methods you could use.

1) Use Rockwool between the studs and hold in place with chicken wire or equivalent (plywood if you can get it in there).

2) Use rigid insulation the same thickness as your studs and hold in place with some nails popped into the studs at the back, then when the insulations in position tap the nail heads a little to hold the boards snug against the plasterboard. If you really want it toasty add a layer of 25mm or so to cover the back edges of the studs. Although frankly if the rest of the loft walls/roof is poorly insulated this is overkill.

Agreed - it would be overkill just for one area of wall.
Whats your view on this foil insulation it's this one
http://www.wickes.co.uk/space-blanket/invt/161206/

I mean it cannot be any worse than what was previously installed?

 

[freddiemercurystwin]

I mean it cannot be any worse than what was previously installed?

Agreed, go for it, pointless going to town on it.

 

[wavetrain]

ToAoB that is not a multifoil so you have not been conned. It is not a 'foil' insulation either, just regular bagged type. A very good product.