Fireguard Gypsum Board

Stephen N

New Member
Apr 3, 2019
12
Columbus, OH, USA
Hello, I have a flue pipe requiring 2" clearance from combustibles. Would a fire-rated gypsum board be able to breach this barrier or would I need to go full cement board?


Thank you!
 

blades

Minister of Fire
Nov 23, 2008
3,486
WI, Leroy
gypsum by itself is fire proof its the paper its wrapped in that is the problem - need to look at fire specs of same- can't trust marketing people.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
21,499
central pa
Hello, I have a flue pipe requiring 2" clearance from combustibles. Would a fire-rated gypsum board be able to breach this barrier or would I need to go full cement board?


Thank you!
No it is only rated to resist fire for 45 mins. It is not noncombustible. Why can't you just maintain the 2" clearance required?
 

Stephen N

New Member
Apr 3, 2019
12
Columbus, OH, USA
No it is only rated to resist fire for 45 mins. It is not noncombustible. Why can't you just maintain the 2" clearance required?

I have a fireplace that wasn't installed to code (discovered after a wall demo). The flue pipe is already installed and cannot be disassembled without completely replacing it, and I need a way to terminated the ceiling around it. Flue collar ceiling kits don't exist for my size flue apparently, so I am planning to use cement board around it and caulk with non-combustable caulking. What do you think?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
21,499
central pa
I have a fireplace that wasn't installed to code (discovered after a wall demo). The flue pipe is already installed and cannot be disassembled without completely replacing it, and I need a way to terminated the ceiling around it. Flue collar ceiling kits don't exist for my size flue apparently, so I am planning to use cement board around it and caulk with non-combustable caulking. What do you think?
Some pics might help
 

Stephen N

New Member
Apr 3, 2019
12
Columbus, OH, USA
Some pics might help
This flue pipe had been closed off behind a wall, and they cut straight through the ceiling, leaving a joist unsupported and code-breaking combustable gaps all around it. I had to open the ceiling, properly header the ceiling joists to and allow proper 2' air gap, and now I have to finish the ceiling, so where there was drywall before I am planning on using cement board so that I can but it right agains the flue instead of a flue collar since I can't find the size I need. The cement board will join the surrounding drywall via mortar and fiberglass tape, then mud and skim coat the whole thing. Does this make sense?
 

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bholler

Chimney sweep
Staff member
Jan 14, 2014
21,499
central pa
This flue pipe had been closed off behind a wall, and they cut straight through the ceiling, leaving a joist unsupported and code-breaking combustable gaps all around it. I had to open the ceiling, properly header the ceiling joists to and allow proper 2' air gap, and now I have to finish the ceiling, so where there was drywall before I am planning on using cement board so that I can but it right agains the flue instead of a flue collar since I can't find the size I need. The cement board will join the surrounding drywall via mortar and fiberglass tape, then mud and skim coat the whole thing. Does this make sense?
Why not just make a metal plate? Also do you have 2" to the left as well?

Also that pipe can be disassembled.
 

Stephen N

New Member
Apr 3, 2019
12
Columbus, OH, USA
I don't have any metal cutting experience, so I'm not confident I could do a professional looking job with that... wouldn't even know how to start. And yea, currently all combustable gaps are to code 2"+ in every direction, allowing extra room for when drywall goes up around it as well
 

mrd1995

New Member
Feb 21, 2020
69
North East, Pa
I do not have the tools to do something like this but keep in mind that Ohio and PA are hot spots for metal fab and machining, you maybe able to find someone once the lock down is complete to do this at a decent price. If you were closer to Erie I could recommend a few guys that do light fab on the side of their full time fab jobs. Just my two cents.
 

Stephen N

New Member
Apr 3, 2019
12
Columbus, OH, USA
I do not have the tools to do something like this but keep in mind that Ohio and PA are hot spots for metal fab and machining, you maybe able to find someone once the lock down is complete to do this at a decent price. If you were closer to Erie I could recommend a few guys that do light fab on the side of their full time fab jobs. Just my two cents.
Thank you, definitely something worth considering, we are going to have metal work done for other parts of this job but haven't decided about this yet. Knowing that this is an option to consider, is there anything wrong with going the cement board return route?
 

mrd1995

New Member
Feb 21, 2020
69
North East, Pa
I would wait for someone with more knowledge and experience to answer that one. I do not want to steer you incorrectly.