Old chimney new clearance.

[Vern Heiler]

Inspection today, permits have been pulled to build-in deck around exterior chimney. The project has not been finished but I am sure it has passed the framing inspection. Roof framing is less than 2" from the exterior of the brick chimney, the smallest gap is 3/4" to the header.

Do I write this up, and what do I use to justify to CEO.

[Bob Harper]

Exterior chimney is now interior> 2" clearance required. I don't see firestopping.

2" clearance per IRC and NFPA 211.

[Vern Heiler]

Thanks Bob

[Vern Heiler]

Exterior chimney is now interior> 2" clearance required. I don't see firestopping.

2" clearance per IRC and NFPA 211.

Bob, I just found this:
1003.18 Chimney clearances. All wood framing members shall be kept at least one (1) inch from chimney masonry and two (2) inches from fireplace masonry, excluding the fireplace facing material. Masonry chimneys which are completely on the exterior of a building against the sheathing are not required to comply with these provisions. (See Figure R1003.18).

I'm feeling a little embarrassed about the 2" requirement I put in the report.:o

[Bob Harper]

Vern, what year version is that? I'm quoting from the 2009 IRC R1003.18 Chimney Clearances. "Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum air space clearance to combustibles of 2 inches (51mm). Chimneys located entirely out the exterior walls of the building including chimneys that pass through the soffit or cornice, shall have a minimum air space clearance of 1 inch (25mm). The air space shall not be filled, except to provide fire blocking in accordance with Section R1003.19. ..."

[James Duffin]

What Vern posted was a change from the 2006 IRC in the NC 2009 IRC.

[Phil Brody]

Never did understand the logic on that.....

[Jim Hintz]

Vern, what year version is that? I'm quoting from the 2009 IRC R1003.18 Chimney Clearances. "Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum air space clearance to combustibles of 2 inches (51mm). Chimneys located entirely out the exterior walls of the building including chimneys that pass through the soffit or cornice, shall have a minimum air space clearance of 1 inch (25mm). The air space shall not be filled, except to provide fire blocking in accordance with Section R1003.19. ..." "Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum air space clearance to combustibles of 2 inches (51mm)." ....With that new finished room, the chimney is now located in the interior of the building - 2" it is....

[Vern Heiler]

"Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum air space clearance to combustibles of 2 inches (51mm)." ....With that new finished room, the chimney is now located in the interior of the building - 2" it is....

Being in a licensed State, anyone can file a complaint to the licensure board including the seller. Complaints can result in no action, additional training, submitting all reports to the licensure board for a period of time, or loss of license. None of which I want to happen!

We are charged with determining if a component or system is functioning as intended. “Intended” is the slippery word. We are expressly discouraged from quoting building code, but can use it as reasoning of “intended”. Because codes change with time like the shifting sands of the Sehira, so does the interpretation of “intended”. Can’t use them, but have to know where they apply geologically and chronologically to stay out of trouble.

In this case the 1” clearance is intended to provide a margin of safety, and the NC code officials have deemed this acceptable.

This is my favorite definition of the HI business:

"A business with illogically high liability, slim profit margins and limited economies of scale. An incredibly diverse, multi-disciplined consulting service, delivered under difficult in-field circumstances, before a hostile audience in an impossibly short time frame, requiring the production of an extraordinarily detailed technical report, almost instantly, without benefit of research facilities or resources." - Alan Carson