What's a good way to support a freestanding chimney?

Question

I'm working on adding a woodstove to a yurt. The chimney will go out a sidewall and then head up. There is not a good way to brace the chimney to the yurt itself.

Here are some options I've read about, but don't know how to judge:

• Use a pair of 4"x4" treated posts. Bed them in the ground in concrete. This is what the yurt manufacturer recommends:

• Build a wooden frame to support the chimney. Pairs of 2"x6"s joined in L-shapes as the corner. Attached to a poured concrete footing w/ 2"x6" treated "sill plates". Could be covered with sheathing & siding.

• Build a masonry column to support the chimney, like this:

• Put a metal pole in the ground, strap the chimney to it. Not sure what kind of pole, or size. Here are some pictures of this:

Any other suggestions?

Answer 1

My first inclination would be to install a concrete footing 3 or 4 feet deep by maybe 1 1/2 to 2 feet square. Put a concrete block or paver in the bottom of the hole to support the pipe. Plumb the pipe (2 or 3 inch galv should work well) with some temp 2X4 braces, then pour concrete into your hole. Be sure to crown the top of the footing a little so water will drain off and not pool around the pipe. The reason I like a large footing is to supply good ballast and avoid any frost heaves.(if you get ground freeze in WA.) Also, don't forget to put a cap on the top of the pipe so water will not fill the pipe. You may also want to paint the pipe with Rustoleum before attaching the stainless straps to the flue. This will help avoid any reaction from dislike metals in contact with each other.

Answer 2

I,too am dealing with the same situation. The side where my stove pipe opening is, is actually 12' off the ground-the yurt is on a slope. So I am doing a combo of suggestions. Cement is poured, I will use a 4x4x16' post anchored in that cement. Then I will use 2 more 4x4x16' post to create a triangle. They will be buried in the ground about 1'. They will be closest to the yurt. Then above the T part of the chimney I will create a square frame with 2x4's attached to the triangle to support the chimney. I have a lot of wind where I am and given how high up it will be I want additional support at the top. I will post pics when I am done. Corina

Answer 3

We have a house that is one storey in places and two storey in others. The chimney is freestanding above the first storey. Recently we added a second-storey room, and had to extend the chimney so it was enough above the new roofline. This meant about 13 feet of freestanding.

You can see it's well connected and footed at the base.

We were required by code to add a "saddle" that braced it back to our roof. Here you can see them working with a mockup:

The real brace went back with a flat line, not that angle as the mockup. The masons built the chimney with flat spots to make it easier to caulk the saddle.

Eventually the saddle was finished just like the roof, including vents. Here it is in progress:

Your saddle would probably be very similar.