Dryling Chimney Walls

djcrip

Hi all I am about to start dry lining my new build in the coming weeks and would like some advice on how to insulate the chimney.
The chimney is a single flue currently only lined with clay flues up the center of the house to service a solid fuel stove in the sitting room. I would like to know is it advisable to insulate the chimney breast in sitting room and stack in upstairs bedroom with 50mm insulated plasterboard? Maybe also consider the stack in attic.

baby fish

Think when I was building my house I came across this, as far as I can remember chimneys should not be drylined.

Little confused from your post? is the chimney in the centre of the house? Only external walls are drylined.

And no need to dryline anything in the attic.

djcrip

thanks for your reply yes the chimney is in the center of the house.

gman2k

It could be drylined with all non combustible materials. Metal drylining sections (in place of timber battens) to take a supalux board for example. Non combustible insulation such as rockwool to insulate.

mfceiling

I wouldn't advise drylining it.

I know a lad down in laois who drylined his chimney breast. Chimney went on fire and he never copped the heat coming from it.

His father who lived up the field came down to tell him but it was too late - roof caught fire and that was the house away. I saw it myself when i went down to price for the replacement ceilings - what a mess.

He told me that he put his hand on the insulated board and there was no heat coming through it!! As the earlier poster has stated - metal stud partition and a supalux board is your job - not insulated plasterboard!!

baby fish

djcrip wrote: »

Hi all I am about to start dry lining my new build .

new build....then the chimney is surely built from block? just plaster it with a scratch coat and skim finish

BryanF

baby fish wrote: »

new build....then the chimney is surely built from block? just plaster it with a scratch coat and skim finish

So is the chimney a larger thermal bridge into the centre of the house?

baby fish

This is what I had in mind, hadn't read it since 2009 :
Page 122 , home bond house building manual, 2009.

"never fix dry lining to a chimney breast unless the chimney breast has been first rendered in sand/cement. An unrendered breast can allow smoke to leak from the fire and enter habitable areas".

So op , just render the chimney first if you decide to dryline the chimney. It hasn't been mentioned above but I think its important to do just to be safe!

Stella Virgo

why would you want to dryline a chimmney breast a lot of heat is given off the chimmney breast during the day and night, which will add heat to the room/house.

jonniebgood1

The Chimney is a thermal bridge but insulating it outside the blockwork will not prevent this unless the cap is also insulated. In general I guess its 6 or 8 blocks width and if passing through the roof it was sometimes overlooked due to the distance of the cold bridge.

Alternatively there are modular systems available where the actual flue pipe receives insulation inside the actual chimney structure. I believe both Scheidel (through Killeshal) and Lagan have these types of system widely available. In the long run this is the way to go.