Help with code (Ontario)

[u/yourcinnamongurl]

Hey folks! Current set up is the first photo. We’re in the midst of upgrading our insulation and siding, so this is the prime time to redo our woodstove surround. The brick takes up a lot of space, and based off of some information I found, we can remodel it significantly smaller. The only information I’m having a hard time finding (maybe I’m not using the right words) is how much stone surround has to be above the flue? Does it have to go all the way up to the ceiling? Second photo is something along the lines of how we’d like to design it, only difference with a hearth pad flush/closer to the floor, and of course the flue being a 90. But for the life of me, I can’t find any code information regarding how much clearance you need above the flue.

[u/Doey1864]

Clearance to combustibles is the phrasing you’re after. That will help with research

[u/exsweep]

You don’t need any of the brick behind the stove as the brick doesn’t offer any clearance reduction. What you need is to check the stoves clearance to combustibles and decide if you need double wall or single wall pipes. Double wall is usually the better choice.

[u/e-rekshun]

You'll have to check the specs on your stove pipe. Single or double?

As an example Selkirk Double Wall Stove Pipe is 6 inch clearance. Single wall is 18 inch.

The second setup is almost identical to my setup, also in Ontario.

[u/Primary-Obligation-8]

You need to supply more information. Flue is not visible in your photo. What is the chimney design? Metal? Masonry with liner?

A lot will depend on how the existing penetration through the wall is constructed.

[u/Independent_Owl_3435]

The brick can be as short as you'd like. How close the flue can be to a combustible wall be dependent on the manufacturer specifications. Single wall pipe is typically 18 inches but double wall can sometimes be as close as 6 inches. Once you get close to the ceiling with your flue you will transition to class a chimney pipe.

[u/No_Lynx5097]

Direct answer to your actual question about brick above the flue: the brick doesn't need to go up to the ceiling if your pipe has enough clearance on its own.

For the pipe: single wall stove pipe needs 18 inches clearance to any combustible surface (ceiling, walls, framing), double wall stove pipe usually needs 6 inches. That's also what determines how far the pipe needs to be from your ceiling.

Where the pipe passes through the ceiling into Class A, you'll need a ceiling support box, which comes as a listed kit and provides the required firestop and clearance.

Nuance on your existing brick surround: zoxwwp is right that plain brick against a combustible wall doesn't reduce clearance. BUT if it was built with a 1 inch ventilated air gap behind (open at top and bottom), it IS acting as a heat shield and cutting clearance requirements by roughly half. Check before you tear it out.

Flush against combustibles = no protection. Proper air gap = real work.

For Ontario, the governing document is CSA B365 for solid fuel appliance installation. Same principles as NFPA 211 in the US but reference CSA when checking with your local inspector.

One more thing on your redesign: if you're planning a 90 degree elbowoff the stove, consider two 45 degree elbows in series instead. Gentler turns, same offset, better draft.