Expert: Bart Ogden - 9/8/2009

Question
QUESTION: Fireplace chimney built in 1896, stacked limestone.  What is best product to fill some holes in the chimney where the mortor has fallen out? Also would like to even our floor of fireplace...it has cracks in it...High heat cement?

ANSWER: Hi Scott,

Are you asking about filling holes in the exterior mortar of the chimney or the interior of the flue?  

If exterior, match the mortar with the type that the chimney was originally laid up with.

If interior and the chimney is lined, I recommend you contact a local CSIA Certified Chimney Sweep to do some on-site diagnosis of your problem.

You can find a CSIA Certified Chimney Sweep at www.csia.org.

If interior and the chimney is unlined, don't use it for venting anything without a lining system.  In this case, I recommend you contact a local CSIA Certified Chimney Sweep to do some on-site diagnosis of your problem.

You can find a CSIA Certified Chimney Sweep at www.csia.org.

If the floor is firebrick, and uneven, remove the firebrick, level the bed with refractory mortar, then install new firebrick with refractory mortar.

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

CSIA Certified Chimney Sweep #2653
CSIA Certified Dryer Exhaust Technician #10
NFI Certified Wood Specialist
NFI Certified Gas Specialist
NFI Certified Pellet Specialist
NFI Master Hearth Professional
NCSG Technical Advisory Council Member

---------- FOLLOW-UP ----------

QUESTION: Thanks for the info above...very helpful.  The chimney is unlined and we plan to install a stainless steel liner inside.  Two questions: 1. What is best way to attach the lower end of liner to top of masonry fireplace? 2. What diameter liner?...opening of fireplace is 32H X 32W X 24D and 42H to top inside of fireplace.  Opening at top of fireplace is 4" X 27".  Height of chimney is 18'.  Thanks.

Answer
The cross-sectional area of the flue must be at least 10% of the fireplace opening.

You'll need AT LEAST 1" all the way around the liner for the insulation.

The liner must be tied into the top of the smoke chamber area with a material like Chamber-Tech 2000 and it must be tied into the top of the chimney as well.  This is NOT a recommended DIY job!

I recommend you contact a local CSIA Certified Chimney Sweep to do some on-site diagnosis of your situation and to provide a proposal for repair.

You can find a CSIA Certified Chimney Sweep at www.csia.org.

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

CSIA Certified Chimney Sweep #2653
CSIA Certified Dryer Exhaust Technician #10
NFI Certified Wood Specialist
NFI Certified Gas Specialist
NFI Certified Pellet Specialist
NFI Master Hearth Professional
NCSG Technical Advisory Council Member