Chimney Foundation

Posts: 68
Joined: Tue. Aug. 23, 2011 12:20 pm
Stoker Coal Boiler: EFM 520
Coal Size/Type: Rice
Location: Eastern Ohio

Post Thu. Oct. 03, 2013 6:58 pm

Thanks for all the tips and observations. Too bad the block doesn't come stamped " this side up" for neophytes like myself. I suppose that I can just start laying the proper side up without consequence. Good to know about the Sakrete Polyurethane.........I like that idea. I see 2 holes in the door frame that I assumed were for attachment to the block and had visions of the block splitting. From what is said about not anchoring the chase to flue tile above the thimble I would assume that is to allow for movement with expansion which would not be as much of a factor below the thimble. The vermiculite I have is fine and flows like sand . I hope it is the right stuff. Should I use refractory cement for sealing the around the thimble opening and the chase since it is below the thimble? I am using type s mortar and stabilizing the flue below the thimble with brick ties on the corners and Heet II to join the flue tile. Do you continue to use the brick ties across the corners above the thimble? I can only catch one stud, so I will put a brick tie in each block as I go up.

About the lime below the ash door. Could you explain its purpose? Acid neutralization? Just pour it down the flue? I will have better than 2ft. of flu below the ash door opening. Also, do you fill all of the voids in the block with vermiculite as well as the area between the chase and flue? Any need for corner vertical rebar and grout?

Too late to epoxy the rebar to the footer. I had a very snug fit with 1/2 inch rebar in a 1/2 inch hole and hope that is satisfactory. The drain is located under a swale away from the building and water has not been an issue.

Thanks everyone!

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Joined: Wed. May. 20, 2009 8:09 am
Hot Air Coal Stoker Stove: Keystoker 90 Chimney vent
Coal Size/Type: Rice
Other Heating: Buderus Oil Boiler 3115-34
Stove/Furnace Model: Keystoker 90 Chimney Vent
Location: Wynantskill NY, 10 miles from Albany

Post Thu. Oct. 03, 2013 10:54 pm

My whole chimney tile and thimble are set with refractory cement which was the recommendation of time back in 1981. Still works like day 1. The brick and chimney cap have been reset twice after the roof penetration. I am much more vigilant now to keep treating the brick and cap with Diedrich Omegaseal 333 breathable water repellent, kind of like Gore-Tex for your chimney.

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Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal
Location: Buffalo/Adirondacks, NY

Post Thu. Oct. 03, 2013 11:35 pm

yup, lime is for acid neutralization.

Heat stop II on everything below and above thimble.

yes, the expansion issues are non-existant below thimble, I typically mortar the flue tight below the thimble.

The fine vermiculite is what you want.

you could fill the cores in the block w/ vermiculite if that makes you feel better, if you want to do it, do it.

Use type S mortar or harder, do NOT use type N if you want your chimney to last.

Avoid rebar in the cores - rebar in a stack is great if you can keep it far away from any potential heat, if you cant, (which you can't as the cores in the block are far less than the recommended 6") then just don't use it.

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Post Fri. Oct. 04, 2013 4:48 am

cant wait to see this project done! more pics please!

Posts: 68
Joined: Tue. Aug. 23, 2011 12:20 pm
Stoker Coal Boiler: EFM 520
Coal Size/Type: Rice
Location: Eastern Ohio

Post Sun. Nov. 10, 2013 10:04 pm

Update with Photos. Not getting enough time to work on it as much as I would like. The thimble area really slowed me down. Wanting to do it once and do it right.
Opening in wall for thimble.
Exterior view of thimble area.
Flue section with thimble opening installed.

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