7.2.2 Chimney Lining

7.2.2.1 Masonry chimneys shall be lined.

7.2.2.2 - The selection of the lining material shall be appropriate for the class of chimney service and the type of appliance connected, in accordance with the terms of the appliance listing and manufactures instructions.

Fireplace Liner Construction

7.2.10 Fireclay Flue liners

7.2.10.1 - Fireclay flue liners will be installed ahead of the construction of the chimney as its carried up.

7.2.10.2 - Liners shall be bedded one on the other in a medium di=uty non water soluble calcium aluminate refractory cement mixture or its equivimalnt. 

7.2.10.4 - Joints shall be left smooth on the inside.

7.2.12.2 - The air space shall not be filled, only enough mortar shall be used to hold the liner in place.

7.2.13.3 - The lining shall extend for the entire height of the chimney to a level not less than 2" above the crown or wash.

7.2.13.2 - The lining shall be carried up as near vertical as possible with a maximum slope no greater than 30 degrees from the vertical.

7.2.14 Multiple flues

7.2.14.1 Where a chimney contains more than one flue, a separation shall be provided between adjacent flues.

7.2.14.2 - The separation shall be of solid masonry wither bonded or security tied to the chimney walls and constructed according to one of the following:

     (1) Not less than 4"

     (2) of reinforced portland or refractory cement concrete not less than 4"

Fireplace flue lining

nfpa fire code 211 quick links

​ The Chimney Clinic

13.7 Evidence of Damage

13.9 - Damaged or deteriorated Liners. If the flue liner in a chimney has softened of 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 all flue gases) the liner 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.