Is there a way to DIY blow foam insulation into cavities?

[Ian Stirling]

I have 12mm un-foil-backed plasterboard over a 2" gap, to a 50cm stone wall. It's a mite chilly, and I'd like to insulate it a bit.

Ripping out the lot, and replacing with plasterboard/celtoex/... is obviously one option, but is "slightly" disruptive, and involves a hell of a lot of work, as well as not inconsiderable expense.

Other ways.

I'd need to apply a vapour barrier to the inside - I'm currently thinking of something like Al foil wallpapered over the walls, and painted over.

I'd then like to drill holes between all the studwork, and simply blow foam into the wall before replacing the plugs, making good, and putting the foil on top.

Is there any means of DIYing the foam injection? Other than buying several dozen bean-bags, and a funnel :)

[BigWallop]

Would the bean bags have flame retardant beans in them? :-))

The proper way would be to strip the lot off and place your vapour barrier against the stone. Then strap the wall with timber studs before filling the gaps between them with fibre wool. Clad the whole lot over with tapered edge 12mm plasterboard, or foil backed stuff if you wish, before sealing the joints and making good the decor'.

Or you could get the new flame retardant paper insulation stuff and a machine to blow it into the holes you make all over the plasterboard.

Going to the expense now will surely save you having to make other bigger changes in the near future. Making good the insulation is a job that needs doing properly from the start, and not bodging it up as you go along.

[John Rumm]

The quick and dirty way might be a few cans of expanding foam filler. The trickey thing would be making sure you get even coverage though.

Not ideal from a decor point of view, but you could just stick foam backed plasterboard on top of the existing plasterboard.

[N. Thornton]

Or waste expanded polystyrene packaging crushed up. Drop notes round your neighbours and you'll have stacks of the stuff in no time.

Blowing it in is only a way to get quantity in faster, any hose blower plus bean reservoir should function. But if your hole's 4" wide instead of 2" theres really no need to blow, just pour.

NT