How To Calculate Fireplace Chimney Height Above Roof - Building Code Tips

www.homebuildi... Visit our website to learn more about masonry, home building and construction repairs. In this video I will provide you with a few different methods you can use to calculate or figure out the height of a fireplace chimney built over a roof.
Here's a reference for similar building code.
R1003.9 Termination. Chimneys shall extend at least 2 feet (610 mm) higher than any portion of a building within 10 feet (3048 mm), but shall not be less than 3 feet (914 mm) above the highest point where the chimney passes through the roof.

[@khalidhasan5938]

I love videos like this! Makes Architectural-life much more simplified, no doubt!

[@willbass2869]

Very timely video. I'm sure lots of folks are considering wood stoves/fireplaces in face of escalating cost for electric & nat gas. Thanks for posting this. Definitely going to 👍 & save for my reference.

[@gregvancom]

Awesome.

[@ruphleswyatt]

Thank you sir taking a test tomorrow this helps me understand 503.5.4 in the IFGC

[@ttfweb1]

I know “2 feet above 10 feet out, minimum 3 feet” has been around since I did masonry in the 80’s. We always ran the brick to this, then the cap and flue were extra - as you said, good for draw.

[@gregvancom]

Thanks for sharing and I was one of the guys who framed the chimneys for prefab metal fireplaces and everyone used the 2 feet as a minimum.

[@Paul-wr1fk]

@jimb4050 UL has determined a 15 ft. minimum height above the top of the firebox. Also so the flue pipes area should be at least 1/12th of the firebox opening for round pipe. 1/10th of square pipe. 1/8th of rectangular pipe. (Pii) 3.14 x 4.25squared =56.71625 sq. Inches of area for your 8.5" pipe. So check your total flue height. And your openings sq. Inch area. Hope that helps!

[@carlwighton4789]

So regs for UK are 2300mm outlet horizontal to meeting the roof. If it's within that it needs to be 600mm higher. Same principle for twinwall flues.

[@jimb4050]

My fireplace smokes into the house. The chimney is 5' high and farther from the ridge than 10'. It has a metal chimney, double wall, but the inside wall is 8 1/2 inches. Could that be the problem? thanks, Jim

[@gregvancom]

If the chimney is to low, it can create drafting problems, but I can't suggest that it is your problem. You can start by checking to make sure the chimney is not blocked in any way and that your damper is open.

[@claytonroberts344]

So if you make it 4'6" higher then the ridge of the roof you should be all good ? But I still have smoke going into the neighbor's house. What to do?

[@MyFortressConstruction]

Tell them to get an air filter. 😉 No, it's hard to have neighbors with a chimney, or chickens, or dogs, etc. You could add onto the height of your chimney, but the fix is for them to figure out, not you, unless you're violating city codes, which, if you're 54" above you're ridge, you're not. Now, as a good neighbor it's important to keep communication open and explain to them these things. Be willing to negotiate, but there's only so much you can do about wind direction and which windows they open...

[@nakosmiltiadis8284]

Hello and thank you for your videos .Is there a rule that tell us in what distance, a tree or taller buildings next to us, starts to effect our chimney?

[@gregvancom]

Good question and I would guess it would need to stay out of the same space or farther if the chimney is not drafting air out correctly and leaving smoke inside house.

[@gurtwuf150]

Appreciate the video. Question. I have seen pellet stove exhausts that protrude directly out of a houses siding. However my pellet stove exhaust has to comply with chimney codes as shown in your video. Is there a reason for that? Apologies if this is a dumb question

[@gregvancom]

From what I gather it helps suck the smoke out and could prevent it from going into your home.

[@BlumpkinSpiceLatte]

So is there a maximum reasonable height for the chimney? If I were to, for instance, put a chimney 10 feet from the ridge of a 12/12 roof, the standard formula says it would be a 12 foot chimney, needing a bracket at 60". I haven't seen anywhere about a bracket higher up than 5", but I'd be more than doubling it so would I need a bracket and is there an upper limit to this formula's application? 12 feet above the roof sounds crazy tall...

[@gregvancom]

I would ask your local building department on this one.