Hanging loftroll

[adamr7747]

Hello,

I'd like to use loftroll insulation vertically in a timber frame wall. I know it's not designed to keep it's shape in that orientation so am wondering about the best way to secure it. I'm thinking just stapling the top & maybe at the edges a bit (I can't do anything at the back and front as there will be a breather membrane & vapour barrier there, respectively), but before I experiment does anyone have any suggestions for a good way to do it? I'm wondering if the stapling will end up "bunching" the insulation so it's not as effective as it should be, or maybe it will even just tear away from the staples over time.

Thanks,
Adam

 

[cdbe]

Friction between the studs will hold it in place both till you board the wall and subsequently. If you pack it quite tight vertically it will minimise any settlement.

 

[DAZB]

You can get cavity batts which are compressed rockwool and easy to cut and install.

 

[thomp1983]

Cavity batts are easier to work with than rolled rockwool.

I've used both, cut them slightly oversize and squash them in, I then use a couple of lengths of duct tape stapled to the insides of the next stud if I'm not going to be putting the plasterboard on for awhile and they've always stayed in place fine.

That's the last one I did, it was done with alot of offcuts so there's alot more tape than I'd usually use, normally it would just be 2 horizontal lengths.

 

[adamr7747]

That's a great idea about using some gaffer tape. I'll give that a try Adam

 

[big-all]

if its compressed say 100mm in a 76mm space the friction may or may not be enough [like my shed nearing 20 years old ]
but tape as such iff 100mm in a 100mm space may fail over time as the weight takes the insulation down [slumps ]

now i have very vague memories including staples each side in my shed but cant remember
if you do use mechanical fixings would need gathering off fiberglass to give thicker material crammed in to fill the space rather than stretched and thin

 

[noseall]

That's a great idea about using some gaffer tape. I'll give that a try Adam

He spent £30 on gaffer tape and additional labour, the same as buying the equivalent batts.

(I'm all for using waste bits, actually )

 

[adamr7747]

He spent £30 on gaffer tape and additional labour, the same as buying the equivalent batts.

Are you kidding? The batts advertised for timber frame are nearly 5 times more per m2 than the loftroll! For my garden room that works at £450 difference (& my labour is effectively free)

Adam

 

[big-all]

have you tried looking at 19x38mm tile batons cheep as chips and treated --- 450 sounds a lot perhaps half that ??

 

[robinbanks]

my labour is effectively free

Interesting valuation of what your time is worth

Agree with fitting slightly thicker (eg 100mm roll in a 75mm stud) but don't "pack it in quite tight" - the effectiveness of wool insulation diminishes as you flatten it because it's the air trapped between the fibres that does the insulating. I've always left mine to expand for a while before use(until the entire roll on the floor for 10 minutes before fitting)

If you do think you'll get slump (eg 100 roll in 100 wall) you can cut it slightly longer and at the top fold it and trap it between a screwed batten, then fit another bit or wool (or better, PIR to compensate for the batten).

Side cross-section cut view of the wall:

Sheathing(brown), wool(yellow) and plasterboard (grey) and at the top the top rail (orange) with batten (orange) screwed (black) through trapping the wool and small slice of PIR(purple) (or more wool)

 

[noseall]

Are you kidding? The batts advertised for timber frame are nearly 5 times more per m2 than the loftroll!

Yeah, we always use loft-roll (for all it does). Cut sideways so that it stays put.....

side.jpg

• noseall
• 22 Oct 2023