I have done a search and read through the wealth of info out there on this topic. Wanted to make sure I have it right.
So looks like most are using Durock firring strips doubled up to get a 1" air gap, then a sheet of Durock, and a brick/stone veneer over that? This gives a 1" air gap between the firring strips and meets code, even tho there is no air gap along the firring strips.
My old manual for the 118 says 800mm clearance to combustibles. Reading the NPFA 211 it looks like slapping brick on top of either durock, or drywall will net a 33% reduction, 1/2 inch non-combustible insulation board over 1 inch glass fiber or mineral wool batts will net 50% reduction. And any method using the 1 inch air gap will net 66% reduction in clearance.
What I am thinking of doing is 2 layers of Micor, one layer of Durock, then a stone/brick veneer over that. I am guessing that would meet the 1 inch of glass fiber, and 1/2 inch of non combustible to meet code for 50% reduction? Meaning I could place the stove ~15 inches from the wall.
The other option would be to either put firring strips and durock over the drywall, then put the stone/brick over that with a 1" gap to meet code, or use 24 ga steel instead of the drywall, then build off of that so the firewall does not extend too far out into the room.
I am just trying to figure out which would be the best/safest method to use to reduce clearance to combustibles, and also trying to figure out how far up the wall this needs to extend, and if it is required where the stove pipe is going through the ceiling?
Thanks,
Pete
So looks like most are using Durock firring strips doubled up to get a 1" air gap, then a sheet of Durock, and a brick/stone veneer over that? This gives a 1" air gap between the firring strips and meets code, even tho there is no air gap along the firring strips.
My old manual for the 118 says 800mm clearance to combustibles. Reading the NPFA 211 it looks like slapping brick on top of either durock, or drywall will net a 33% reduction, 1/2 inch non-combustible insulation board over 1 inch glass fiber or mineral wool batts will net 50% reduction. And any method using the 1 inch air gap will net 66% reduction in clearance.
What I am thinking of doing is 2 layers of Micor, one layer of Durock, then a stone/brick veneer over that. I am guessing that would meet the 1 inch of glass fiber, and 1/2 inch of non combustible to meet code for 50% reduction? Meaning I could place the stove ~15 inches from the wall.
The other option would be to either put firring strips and durock over the drywall, then put the stone/brick over that with a 1" gap to meet code, or use 24 ga steel instead of the drywall, then build off of that so the firewall does not extend too far out into the room.
I am just trying to figure out which would be the best/safest method to use to reduce clearance to combustibles, and also trying to figure out how far up the wall this needs to extend, and if it is required where the stove pipe is going through the ceiling?
Thanks,
Pete
