insert stove in pir backed plasterboard

bemak

I recently put an insert stove into an existing fireplace. When we stripped back the existing chimney to the blockwork it was quite rough so we decided to mechanically fix insulated plasterboard to it as this would absorb the bumps and hollows.

The stove is it's and we only started to use it in the last week. We've started to notice that a small area above the stove gets very hot. You can just about touch it. The insulation isn't in contact with the stove but obviously it's quite close.

I read online that PIR insulation can stand temps over 200 degrees. I checked it earlier and there isn't a bother on it. Just wondering what ye think

Thanks

Barry

mickdw

So you have removed everything from the chimney including fire place and all finishes then mechanically fixed insulated slab, then replaced fireplace and had stove installed?

bemak

Exactly ya. It's basically blockwork with an insulated plasterboard on the face. Stove set in. I'm just wondering if there's a risk of the insulation going up.

mickdw

Have you got a fire place around it or is it all stove.
Stove itself should have instructions relating to surrounding materials.
If its an inset stove with a traditional fireplace, the fireplace installation is the important bit.
Fire / heat shouldn't be able to get escape to the plaster board area at all.

bemak

No fireplace at all. Just looks like a stove in a wall now. So it's almost in direct contact with the plasterboard.

BryanF

I used supalux (promat)

You should remove the PIR and use suitable board with mineral (stone) wool behind for packing if required.

mickdw

PIR is not readily flammable however in theory it will ignite so I wouldn't want it exposed to continued heat.
I'd be inclined to at least remove a section surrounding stove.
I'd also make sure that there was no possibility of air movement behind the board.

BryanF

https://www.housing.gov.ie/sites/default/files/migrated-files/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad%2C37240%2Cen.pdf

Diagram 14

listermint

1.Stop using it

2. So as described above. The stove should not be that close to pir. No.

bemak

Thanks for the replies. The cavity above the stove where the flue extends into the chimney is packed with rockwool. If I packed more around the edge of the stove where I have the gap between it and the insulated board would that improve the situation?

bemak

Gonna rip it all out. I'd rather it done right than be worrying about it. Thanks for the advice and suggestions