Expert: Bart Ogden - 4/26/2004

Question
our appartment building (pre-war)has problems with the boiler system (sut-needs cleaning out).
We were told that the chimney lining needs to be replaced.
What caused the damage to the lining?
How serious is this problem..what are the hazards of not acting quickly?
What is the best way to locate a certified chimney expert to help fix this problem?

Answer
Dear Jide,

Many things can contribute to the failure of vitreous clay chimney linings cracking.

These include, but are not limited to, chimney fires, water intrusion, freeze/thaw cycling, wet cycling and hydrochloric acid corrosion from oil-burning soot.

ANY damaged chimney lining should be replaced immediately and before any further use of the system in order that the system properly vents and exhausts all the byproducts of combustion.

Hazards can include carbon monoxide leakage into the living areas of the building, heat transferrance to the combustible structural members of the building, loss of property and loss of life.  If the chimney lining is defective or damaged, it should be replaced immediately.

Relevant National Chimney Standards information to this evaluation is as follows:

According to the National Fire Protection Association Publication 211, The Standard for Chimneys, Fireplaces, Vents and Solid-Fuel Burning Appliances, Chapter 4, Section 2.3, “Fireclay flue liners shall be installed ahead of the construction of the chimney as it is carried up, carefully bedded one on the other in a medium-duty, nonwater-soluble calcium aluminate refractory cement mixture, or it's equivalent with close-fitting joints left smooth on the inside.  Portland cement bonded mixtures shall not be used”.   {This section states that there shall be no voids between flue tiles in the system, otherwise the system shall be deemed unsuitable for use.}

Additionally, NFPA 211, Chapter 10, Section 8 lists, under “Operating Malfunction”, “When inspection or an operating malfunction shows that an existing chimney, fireplace, or vent is damaged, unsuitable, or improperly sized, it shall be repaired, rebuilt, or resized to the construction and functional requirements of this standard.”

Continuing with NFPA 211, Chapter 10, Section 9, “If the flue liner in a chimney has softened, cracked, or otherwise deteriorated so that it no longer has the continued ability to contain the products of combustion (i.e., heat, moisture, creosote, and flue gases), it shall be either removed and replaced, repaired, or relined with a listed liner system or other approved material that will resist corrosion, softening, or cracking from flue gases at temperatures appropriate to the class of chimney service.”

I would suggeest you check out www.csia.org and www.ncsg.org to find a CSIA Certfied Chimney Sweep who is also a member of the National Chimney Sweep Guild.  Both websites have locators on them to help you.


I hope this information has been helpful.

Sincerely,
A. Bart Ogden
President
Home Safe Hearth & Chimney
Wichita, KS
Voice: 316-265-9828
Fax: 316-625-9890
www.homesafeks.com