I am about to tackle an attic air seal and insulation project and wanted to get a little advice. I have a masonry fireplace in the middle of the house that penetrates through the attic. When I installed my insert a couple of years ago, I used an 8" insulated stainless steel chimney liner from the insert to the top of the chimney. I know there are code requirements that don't allow you to use combustible air seal and insulation products within a certain distance from the cinder block in the attic. When I looked up some information on building code, I found the following example:
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"Code R1001.15 Chimney clearances. Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimumair space clearance to combustibles of 2 inches (51 mm). Chimneys located entirely outside the exterior walls of the building, including chimneys that pass through the soffit or cornice, shall have a minimum air space clearance of 1 inch (25.4 mm). The air space shall not be filled, except to provide fire blocking in accordance with Section R1001.16.
Exceptions:
1. Masonry chimneys equipped with a chimney lining system listed and labeled for use in chimneys in contact with combustibles in accordance with UL 1777 and installed in accordance with the manufacturers installation instructions are permitted to have combustible material in contact with their exterior surfaces."
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The liner I bought and installed says it is "UL 1777". I just don't know if it is "labeled for use in chimneys in contact with combustibles". My questions is do you think this exception apply in this case? In other words, since I installed the liner, can I air seal and insulate right up to the cinder block without worrying about the clearances and type of insulation?
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"Code R1001.15 Chimney clearances. Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimumair space clearance to combustibles of 2 inches (51 mm). Chimneys located entirely outside the exterior walls of the building, including chimneys that pass through the soffit or cornice, shall have a minimum air space clearance of 1 inch (25.4 mm). The air space shall not be filled, except to provide fire blocking in accordance with Section R1001.16.
Exceptions:
1. Masonry chimneys equipped with a chimney lining system listed and labeled for use in chimneys in contact with combustibles in accordance with UL 1777 and installed in accordance with the manufacturers installation instructions are permitted to have combustible material in contact with their exterior surfaces."
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The liner I bought and installed says it is "UL 1777". I just don't know if it is "labeled for use in chimneys in contact with combustibles". My questions is do you think this exception apply in this case? In other words, since I installed the liner, can I air seal and insulate right up to the cinder block without worrying about the clearances and type of insulation?
