Space between flue pipe and lintel?

LCK73

Does anyone know how much space you need to leave between a double insulated flue pipe and a stone lintel i.e. a non combustible lintel? I'm after the minimum because my chimney opening is only 9inches from back wall to the back of the stone lintel.....

Any info anyone?

hayden

some by-laws state a minimum of 1inch gap between the flue and any noncombustable material

Canucklehead

Good morning: Have you taken a look at Part J Building Regs?

HTH

Canucklehead

LCK73

Thanks, had look through the regs and can't see anything relating to distances for non combustable, only refers to combustable.
Only reason I'm asking is my HETAS engineer doesn't know himself (can you believe that), so i'm trying to find out to avoid having to rip out my skinny fireplace and start rebuilding again.....!

rjm2k1

If the regs don't mention it there's probably no minimum. A stone lintel is hardly any different from the brick the flue will be passing through anyway. I would have thought that in addition to combustion, the major issue with a metal lintel would be that heat would soften it and reduce its strength.

LCK73

It now transpires there is no specific reg relating to this issue, so just to be cautious we will leave a 2 inch gap between the vit pipe and the stone.

Fingers crossed.