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Expert: - 9/26/2007


Question
I am building a concrete block chimney on an outside wall of my shop to receive a wood stove. I have constructed a footing 3' by 3'.  concrete blocks begin at ground level forming a 24" long by 32" wide base. At 2' above ground level I have started the flue and surrounding concrete flue blocks (16" x16")This will go up 12 feet.
My questions is :
1)what to lay butting the flue blocks to the outside edges of the base and how to secure them. In other words I have 8 inches on three sides of the flue blocks to add some kind of masonry (brick or concrete block). How do I do that?
Secondly, how far up the chimney should I bring this outside layer?
Hope this is clear. Thanks

Answer
Hi Tom,

The flue tile should start at least 6" below, but not more than 12" below the bottom edge of the cleanout opening.

The flue tiles should have a minimum of 1/2" and a maximum of 4".  The air space should not be filled and only enough tile-setting mortar should be used to make a good joint and hold the liners in position.

You'll have to use some brick to close down the open space from the bottom clear to the top.

The flue tile needs to go to the top of the chimney and extend at least 2" above the crown, spay or wash. I recommend they don't extend more than 8" out of the crown splay or wash.

Thanks for using AllExperts.Com and good luck with your project.

Sincerely,
A. Bart Ogden, President
Home Safe Hearth & Chimney, Inc.
Wichita, KS
Voice: 316-265-9828
Fax: 316-265-9890
www.homesafeks.com

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Bart Ogden

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I can answer questions related to chimney and fireplace cleaning, construction and repair as well as questions related to the performance of chimneys and fireplaces. I can also answer questions related to clothes dryer vent cleaning and repair. Additionally, I can field questions related to masonry repair.

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Experience in the area:
28 years experience in the chimney service/installation/repair field
President, Home Safe Hearth & Chimney, Inc. Wichita, Kansas

Professional Organizations:
Member, National Chimney Sweep Guild (NCSG)
Member, Hearth, Patio & Barbecue Association (HPBA)
Member, Kansas Guild of Professional Chimney Sweeps (KGPCS)
Member, Midwest Chimney Safety Council (MCSC)
Member, Kansas Association of Real Estate Inspectors (KAREI)
Past At-Large Director of the National Chimney Sweep Guild
Past At-Large Director of the Chimney Safety Institute of America
Past Secretary, National Chimney Sweep Guild
Past Secretary, Chimney Safety Institute of America
Member, National Chimney Sweep Guild Technical Advisory Council
Member, Chimney Safety Institute of America Certification Committee
Past Chairman, CSIA Chimney Safety Education Brochures Committee
Past Chairman, NCSG Nomination Committee

Publications:
SWEEPING Magazine, The Journal of Chimney & Venting Technoloty, A Publication of the National Chimney Sweep Guild
SNEWS, The Chimney Sweep News
THE KANSAS SWEEP, The Voice of the KS Guild of Professional Chimney Sweeps

Education/Credentials:
BA, Wichita State University
C.S.I.A. Certified Chimney Sweep
C.S.I.A. Certified Dryer Exhaust Technician
N.F.I. Woodburning Specialist
N.F.I. Gas Specialist
Chimney Diagnosis & Documentation Seminar
Ahren's Masonry Restoration School Graduate
Advanced Gas Certification
Master Gas Certification
Licensed Mechanical Contractor
Pellet Appliance Specialist
Venting Design Specialist
Dale Carnegie Course Graduate

Awards and Honors:
Superior Dealer Award, Ventinox Chimney Lining Systems

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