Fire boxes and Smoke Chambers

Recently we came across an issue with a Level II inspection that our company did on 4 fireplaces.

“Upon arrival our chimney professional Michael Kozlansky provided a Level II inspection.” (A Level II chimney inspection is performed with a camera at the time of any cleaning, for real estate or insurance- or as an annual check provided by homeowner) The chimney professional found that the brick inside the smoke chamber were “corbeled”. (The smoke chamber is the transition area in a masonry chimney that starts just above the damper and continues to where the first flue tile is installed. It serves as the support for a clay tile flue liner. Chambers are usually corbeled brick or block work, starting wide at the base and narrowing down to accommodate the flue liner. Most chambers are 3 ft – 4 ft in height, but can be shorter or taller and out of proportion.) (Testing shows that chimney fires can reach well over 2100° F. After the fire is out, the chimney continues to heat up. Expansion due to excessive heat causes cracks and mortar bond breaks, surface spalling of the brick, and sometimes in severe fires, cracks occur through the brick or block. Most of this type of cracking in the chase occurs in the smoke chamber area and at the top of the chimney)

Our report indicated to the customer that the corbeled brick should be covered with a smooth surface, to protect the smoke chamber should be free of any gaps, cracks, or jagged edges. According to the National Fireplace Protection Association Code 211. National Fire Protection Association (NFPA) 211Standard For Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances 2010 Edition 11.2.1.13 The inner surfaces of the smoke chamber shall be parge coated smooth, with an insulating refractory mortar, Corbelling of masonry units shall not leave unit cores exposed to the inside of the smoke chamber.. Firebrick shall be laid with medium duty refractory mortar confirming to ASTMC199.. When the inside of the surface of the smoke chamber is formed by corbelled masonry, the inside surface shall be parged smooth to protect the integrity and efficiency of your fireplace.

After giving the potential home buyer the report, the current homeowner hired his current chimney person who has been maintaining his chimney regularly.

This is his company’s report:

Smoke chambers do not show signs of damage and do not need to be parged. This is not required for the sale of home, nor when the home was built.

Back to our inspection: If a potential customer calls our company, they are calling because they are putting their family’s safety first. When we inspect any fireplace we will go with all the newest codes according to the National Fireplace Protection Association. There is a reason that codes change, and according to records 60% of all chimney fires occur in the smoke chamber. Knowing this we give recommendations and an estimate based on the camera inspection done. With these statistics and the new codes we must comply and give the recommendations of the professionals at (NFPA) to ensure the complete safety of our customers and keep our reputation as a family run and oriented business. “We care about you!”

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