How to hold insulation up when pb'ing ceiling ?

[slowlybutsurely]

I've inherited a large amount of unused 75mm Rockwool insulation (long story). And I'm soon going to be re plaster boarding a ceiling. Joists are approx. 350mm oc., ie approx. 300mm between the joists but it varies a lot (old building). I'll be cutting each length to fit the width.

I want to add the insulation - 2 layers in fact (they are deep joists), but I'm going to need a way to hold the insulation in place whilst I raise and fix the pb in place. Ideas please? I've read somewhere about using a type of thin garden mesh/netting, stapled in place - is this ok? (allowed?). Any other ways? (overstuffing the insulation isn't good right?)

Thanks

 

[Burnerman]

I just cut some timber strips slightly wider than the joist and then spring them in......works well enough for me!
John

 

[Handymanjo]

Go to wilko and get fruit net and staple net to under side of joist,then you can plaster board over the net when the insulation is between the joist.

 

[cjard]

You might find string or ribbon(like what you tie on balloons at weddings) easier than netting

On the first joist staple a length of string that is the width of the room every 600 to 800 mm with the first run 300mm from the wall
When lifting the insulation in it helps to have an assistant with a broom going ahead of you doing a bit of lifting but it can be done on your own.
Lift the insulation and draw the second (not the one nearest wall) string across, and fix. Proceed to the third, fourth etc, then go back to the first. If you do the first one first you might find that there isn't enough "drape" in the wool to flap down over the string and prevent the weight of the rest of the wool from pulling itself down and onto the floor.


Gotta admit the wood idea is a great one and a sheet of 4mm ply ripped into 40mm strips would work well and probably be less hassle than the string method, just a bit more costly (and needing a table or good circular saw).

Buy a good dust mask, one that has a rubber moulded part and elastic straps that go round the back of your head and neck.

 

[cjard]

Actually, having just read that your joists are at. 350 centres I think you'll find the wool will stay up there if you just cut it to slightly over that width and push it in.. If the timber is rough then it'll hold even better.
If your joists are taller than 150 I'd also full fill if you can as 150mm of wool isn't a lot and joists at 350mm is a lot of joists, hence a lot of thermal bridging. Might also be good to board the underside with 25mm kingspan before the PB goes up!