Thread: insulation in existing gyprock wall

1: Expanding foam is expensive
2: Gyprock is relativily cheap

I would remove the gyprock on one side of the wall, then insulate with batts or whatever your budget allows. there can be a big cost difference in acoustic batts.

then re sheet the wall with two layers of gyprock, offset any joins to help stop the sound travel.

repaint ect and you have a rather good sound barrier.

Cheers Ian

I have seen an "architect" suggest the expanding foam option (he had forgotten to mark it on plans), then against the advice of the plasterer, who had seen the result before...insisted it happen!

Result: sometimes the foam expands a little too much for the 10mm plasterboard especially if the studs are at 600mm centres and rather amusing lumps appear in the wall and expanding foam pours out of the hole down the front of the wall !

Go with Ian007's idea - patching a couple of holes in a wall can still be seen if the wall has glancing light. Re-sheeting with two layers of 13mm with polyester partition blanket in the void will ensure that even the biggest two year old tantrum can be escaped.

Oh and if you really want to get carried away, hop up into the ceiling space and continue the wall to the underside of the roof joists and lay 1200mm of insulation above the ceiling on both sides of that wall .

Then all you need is a great big leather chair and a moosehead on the wall and the office becomes a Gentleman's retreat

I've seen expanding foam poured into a wall distort the plaster sheets too.

Another alternative might be to drill holes between studs (above and below noggins) and pour beanbag styrene foam balls into the wall cavity. It should work and theres only small holes to patch up.

I would be getting granulated Rockwool pumped into the cavitys. Can be done by drilling a small hole for the hose.

Have a look here.

http://www.ais-group.com.au/homeinsu...avitywalls.htm

The problem with expanding polyurathane insulation is the control of the expansion within the wall as it will blow the gyprock off.

Anothe alternative is to drill holes and fill the cavity up with polysterene beads and then just plaser up the holes.

Originally Posted by Ian007

1: Expanding foam is expensive
2: Gyprock is relativily cheap

I would remove the gyprock on one side of the wall, then insulate with batts or whatever your budget allows. there can be a big cost difference in acoustic batts.

then re sheet the wall with two layers of gyprock, offset any joins to help stop the sound travel.

repaint ect and you have a rather good sound barrier.

Cheers Ian

If you go this alternative I would use Bradford Sound screen batts

See here.

http://www.bradfordinsulation.com.au...eace+%26+Quiet

Use Sound insulation definitely, but it may be just as easy, and more effective, to simply sheet over both walls with another layer of Gyprock Soundboard.

The additional density will give you better sound insulation than insulation, but don't forget you have only one single layer of ceiling, so making the walls perfectly soundproof will only marginally improve the situation for the whole room.

Try one layer of gyprock on one side first, and see what difference it makes, then you can decide whether to go with the insulation or another layer or both.

Sound insulation layed over the ceiling of one room will also help.

Check out http://www.gyprock.com.au and follow the sound insulation links for all the information you are likely to need. There's a fair bit of interesting reading.

Cheers,
P

Thanks for all the suggestions. I have thrown out the window the idea of the expanding foam.

With the thought of re-sheeting I am starting to lose enthusiasm for the project.

I could just pretend I'm deaf.

Someone on another forum suggested CUTTING the existing plasterboard out one side only.. 50mm from the wall, cornice, floors etc, this will solve the problem of cornice not being nicely joined in.

Then put the rockwool or insulation batts or whatever in, and put the sheets back on and plaster the join.

Could be one of those jobs that gets harder as the day gets on.. Just have to see.

Anyway - I think I'd prefer to go with that option now - cut off one plasterboard side, batts, then re-sheet.

I've got polyester batts in the ceiling so that's fairly well insulated now.

Oh - and for those who asked.. I'm a guy OK! so the suggestion of a moose's head and leather chair sits real nice.

Originally Posted by alwayscurious

Oh - and for those who asked.. I'm a guy OK! so the suggestion of a moose's head and leather chair sits real nice.

What idiot:eek:
would ask if you were a bloke.....................................
Just 'cause a girlfriend spends most of her day in the shed, or the workshop cutting and rejoining timber and Gal;

She makes Oz Flags out of Cattle Station Scrap

foam insulation is incredible with a few caveats

expensive at around 3 times fibreglass
wall needs to be open on one side
special equipment is required

Benefits

incredible thermal and audio insulation properties
does not compress
if done in a certain way, can be solid plastered immediately

But it isn't the same as Plumber's foam - completely different expansion properties

Anyway, personally I would do what you are planning to minimize impact - if I was doing it though, I would probably add a one inch thick foam to the wall and replaster over the existing, but I get where you're coming from re: the cornice, skirts etc. You will still have to marry in all the patches so I guess a fine tooth jigsaw would be the way to remove the existing plaster. then you could just add glue-edges to the holes and put the plaster back. Once patched by a plasterer it would be invisible I imagine.

have fun!

hi,

not sure if you are still looking for a solution, but there is a pump-in-foam product that can be retrofitted to the stud wall via a small drilled hole. The foam does not expand in the cavity so you dont have to worry about blowing the walls off. www.foamedinsulations.com.au look at the product retrofoam or polymaster

cheers