Plaster board with insulation how to fix it?

anna.bloom

Hello

Our plasterer is insulating our out house, as its a single skin 9 inch wall. He is using plaster board, that has insulation attached to it. It white polysterene.

He is just gluing these on to the wall with adhesive, is this ok? i worry what will happen if moisture gets trapped in there. Does he need to bolt them to the wall?

He is a very good old fashioned plasterer, but not sure he knows alot about insuation boards.

andyhop

Yes dri-wall adhesive will be fine, Allow 1 bag per 2 boards minimum

These boards should also have gyproc hammer plugs fitted in case of fire to keep them on the wall

ormus

as above. you need two types of fixing. (together).

de1amo

how big is a bag of the adhesive--i have a place abroad and things are never standard--do you know how efficient this type of insulation is? is it worth lining a concrete ceiling

iamcornholio

andyhop wrote: »

Yes dri-wall adhesive will be fine, Allow 1 bag per 2 boards minimum

These boards should also have gyproc hammer plugs fitted in case of fire to keep them on the wall

If the boards fell off the wall in the event of fire, then the wall behind will not be affected at all, so extra mechanical fixing is not required in most cases.

Extra fixings are only rquired if there is a void behind the boards, which would allow flame or fire to spread through the void to other rooms etc if a board fell off the wall

MX5huggy

de1amo wrote: »

how big is a bag of the adhesive--i have a place abroad and things are never standard--do you know how efficient this type of insulation is? is it worth lining a concrete ceiling

The adhesive comes in 25kg bags.

If all that is between you and the outside is concrete then yes. I would probably op for a celotex/kingspan backed board as thick as you can accommodate/afford. This presumes your climate is UK ish.

andyhop

iamcornholio wrote: »

If the boards fell off the wall in the event of fire, then the wall behind will not be affected at all, so extra mechanical fixing is not required in most cases.

Extra fixings are only rquired if there is a void behind the boards, which would allow flame or fire to spread through the void to other rooms etc if a board fell off the wall

Fixings are required,Would you be happy to try to escape fire only to be hit by a falling sheet of plasterboard? Please read the gyproc website

You only ever use these boards for outer walls

anna.bloom

We have kitchen units going up on those walls, so i guess if we had a fire, the units would fall off the wall too?

I am more worried about the condensation. Where is the cavity, surely teh moisture will run down the side of the polystyrene and get gammy and run down to teh floor?

Dont you need a bit of an air space between insulation and a cold wall, or maybe thats what the polystyrene is for?

Building regs have said we need 5cm! of that expensive foam type insulation with a stud wall. No way, we wont have a kitchen left! 10cms would take too much out of the room.

de1amo

If all that is between you and the outside is concrete then yes. I would probably op for a celotex/kingspan backed board as thick as you can accommodate/afford. This presumes your climate is UK ish.[/QUOTE]
Lol no point owning abroad if its as bad as this lol--its very dry -cold in the winter and red hot in the summer--the ceiling has a pitched roof above it-not sure what fibre they have insulated with in it because its sealed-it just seems a week spot in places with top floor aspect -

andyhop

anna.bloom wrote: »

We have kitchen units going up on those walls, so i guess if we had a fire, the units would fall off the wall too?

I am more worried about the condensation. Where is the cavity, surely teh moisture will run down the side of the polystyrene and get gammy and run down to teh floor?

Dont you need a bit of an air space between insulation and a cold wall, or maybe thats what the polystyrene is for?

Building regs have said we need 5cm! of that expensive foam type insulation with a stud wall. No way, we wont have a kitchen left! 10cms would take too much out of the room.

If your hanging kitchen units on these walls i would advise that you use a timber frame and fit kingspan between timbers, damp proof membrane external walls aswell

Make sure you get plenty of timbers in the wall to fix the units to

Have you got details of what BC require, Most of the cheaper end thermaline boards dont have good u values so may not be suitable

anna.bloom

Thanks for all of your help.

We are running out of money, and space in the kitchen, so cant afford to replace insulation. We have already bought it, and if we put timber frame up, we would lose to much space, kitchen is small as it is.

I dont care about the heat so much as the damp. and the walls getting all mouldy.

Building control came round, and dont mind what we do from a regulatory point of view, but their advice is 5cm like you say on timber frames.

I just want someone to say, yes that will be fine with the polystyrene backed plaster board. I guess this is what the product is for? as it is not suitable for ceilings.