How high should a chimney be? well the height requirements rule that is followed in the United States and Canada is called the 3 2 10 chimney rule, this means that a chimney must be 3 feet higher than the point it exits a roof, and also be at least 2 feet taller than any part of a roof or building that is within 10 feet of the chimney.

So this is a very common problem, chimneys are often built too low and most likely your local chimney sweep came to do an insurance inspection and he was the one who gave you the bad news and told you it was too short and maybe gave you a few tips on how to remedy the problem.

So to understand this rule better and make sure your chimney is tall enough, continue reading and please feel free to share this article with anyone you know who may benefit from it.

Height does matter when it comes to chimneys

Jonathan A

What is the 3, 2, 10, chimney rule?

It is actually quite easy to understand the wood-burning fireplace chimney height rule and is important to follow so that your chimney is code compliant and your home can be insured.

Following this simple fireplace chimney height code will eliminate many chimney problems, for example, your fireplace smoking, or a fire on your roof if you have a chimney fire.

YouTube video
This video from is an excellent guide to demonstrating the 3 2 10 chimney code.

Understanding Chimney height requirements 3-Foot Rule 2-Foot 10-Foot

So now let’s take a look at the wood-burning fireplace chimney height requirements below.

  1. So the first measurement starts from the point the chimney exits the roof, it needs to be a minimum of 3 feet tall.
  2. Then a minimum of 2 feet above any roof line or obstacle
  3. The roof line or obstacle must be at a horizontal distance of 10 feet where it meets the 3-foot height.

So If that was at all confusing I am adding some drawings below for you to see visually how this rule works.

3 2 10 chimney rulePin
This picture shows a steep-pitched roof
3 2 10 chimney rulePin
This picture shows a low-pitched roof

Does the height of a chimney matter?

Chimney height is actually very important because you eliminate many potential problems, for example, your chimney may not draw properly, also in the case of a chimney fire your roof could catch on fire, no one wants that to happen.

Remember your home needs to follow these measurements to be code compliant according to the WETT Reference Manuel, this being the standard in Canada.


Fix your height

There is really only one thing you can do to remedy a short chimney so that it is code compliant, and that makes it taller.

If you have a masonry chimney you will need to hire a mason to build an ad onto the chimney, the part that can be difficult with this is getting the exact color of brick to match.

for stainless steel chimneys, you can add on another length of the chimney, just remember the chimney must be the same brand and cannot be mismatched with other brands or sizes.

Are taller chimneys better?

Taller chimneys are almost always better, the internal pressure pushes flue gases up and out of your home.

Your chimney should always be higher than the house if it is not your house could be competing with your chimney causing pressure problems and not allowing it to work properly.

Having a chimney that is taller than needed is not always necessary and can look out of place also a chimney that is too tall can have problems drawing, so it’s always good to find that sweet spot, and that’s why the 3 2 10 chimney rule makes helps set the standard.

How high should a chimney be? a chimney sweep can help.

If you are still unsure if your chimney is the right height you can always ask your local licensed chimney sweep, they have the knowledge and training to determine the 3 2 10 measurements are correct, and they have the ladders to do a proper inspection on your roof.

Thank you for reading this post if you found it interesting please share it with friends.

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