NCSG Manual Library
Originally published in the July 2014 issue of Sweeping Magazine
Question: The International Code Council updates and releases a new International Residential Code every three years. Does that mean my state will adopt a new IRC or specific changes every three years?
by Mike Segerstrom
Answer:
It depends on your state. Some states may be on a three-year cycle, or even a six year cycle. And many states will make changes to the IRC before they adopt it. Changes may affect us, so it's important to know what year our state has currently adopted, and if there's a state specific version. There may also be changes or updates in the current edition of the IRC that our state hasn’t adopted yet.
Let's take New Jersey for an example. New Jersey currently follows a 6 year cycle for the International Residential Code changes. It currently follows the 2009 addition of the IRC, with state specific additions, deletions, and changes. Its called the 2009 IRC New Jersey Edition. Let’s look at an example from chapter 10:
In Chapter 10 Chimneys and Fireplaces, Section R1003 Masonry Chimneys, Subsection 1003.18 Chimney Clearances, Exception # 3, the 2009 IRC states the following:
“3. Exposed combustible trim and the edges of sheathing materials, such as wood siding and flooring, shall be permitted to abut the masonry chimney side walls, in accordance with Figure R1003.18, provided such combustible trim or sheathing is a minimum of 12 inches (305 mm) from the inside surface of the nearest flue lining. Combustible material and trim shall not overlap the corners of the chimney by more than 1 inch (25 mm).
FIGURE R1003.18 CLEARANCE FROM COMBUSTIBLES
Notice that it says “12 inches” is the required clearance from the inside of the flue liner to adjacent combustible sheathing.
In the 2009 IRC New Jersey Edition, the same Exception reads as follows:
“3. Exposed combustible trim and the edges of sheathing materials, such as wood siding and flooring, shall be permitted to abut the masonry chimney side walls, in accordance with Figure R1003.18, provided such combustible trim or sheathing is a minimum of 6 inches (305 mm) from the inside surface of the nearest flue lining. Combustible material and trim shall not overlap the corners of the chimney by more than 1 inch (25 mm).”
Notice that the 12” requirement was been amended by New Jersey to only 6 inches.
A 16” x 16” brick or block exterior chimney with an 8” x 8” clay tile liner with the required standard 1” airspace (R1003.18) does not meet the IRC requirement of 12” if sheathing and siding abut the chimney. This size chimney will however meet the requirements of the NJ Edition of the IRC.
This is just one example of a change NJ has made to the IRC that directly affects those of us that work there. Other states have made similar changes. The best thing to do is check with our current state Adopted Code when it applies to the project or job we are considering working on. We should also check with that local jurisdiction, as certain towns, cities, municipalities, etc., may also have their own revisions or codes.