bill1952
SAWHORSE
Probably not going to find an answer but here it is from 2012 with commentary:
2012 footnote b. to table 601:
Except in Group F-1, H, M and S-1 occupancies, fire protection of structural members shall not be required, including protection of roof framing and decking where every part of the roof construction is 20 feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
2012 commentary
Note b applies to the construction of the roof and related secondary members in all types of construction. It allows these elements to be of unprotected construction when all parts of the roof construction are more than 20 feet (6096 mm) above any floor below. This allowance only applies to the secondary members of the roof structure and not to primary structural frame located within the roof or at the roof level [see Figure 601(1)]. This alternative is applicable for all occupancy classifications except Groups F-1, H, M and S-1. Figure 601(2) shows an example where a mezzanine reduces the clearance to the roof to less than 20 feet (6096 mm) for a portion of the total roof. Designs similar to Figure 601(2) do not comply with note b, and elimination of fire resistance is not allowed for any of the roof.
I cant find the justification for the bolded commentary sentence in the code. Anyone point to supporting the commentary requiring primary structural framing in the roof being excluded from the footnote b. allowance?
The footnote changed in 2018 footnote b. to table 601:
Except in Group F-1, H, M and S-1 occupancies, fire protection of structural members in roof construction shall not be required, including protection of primary structural frame members, roof framing and decking where every part of the roof construction is 20 feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
I don't have 2015 or 2018 commentary, but 2021 commentary is changed:
Note b applies to the construction of the roof and related secondary structural members in buildings of Types IA, IB, IIA, IIIA and VA construction. It allows these elements to be of unprotected construction when all parts of the roof construction are more than 20 feet (6096 mm) above any floor below. This allowance applies to both the primary and secondary members of the roof structure. This alternative is applicable for all occupancy classifications except Groups F-1, H, M and S.
Anyone disagree that all of the roof framing that meets the 20' - and yes all of the beam must be above 20', not just a portion of the beam - may be unprotected?
2012 footnote b. to table 601:
Except in Group F-1, H, M and S-1 occupancies, fire protection of structural members shall not be required, including protection of roof framing and decking where every part of the roof construction is 20 feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
2012 commentary
Note b applies to the construction of the roof and related secondary members in all types of construction. It allows these elements to be of unprotected construction when all parts of the roof construction are more than 20 feet (6096 mm) above any floor below. This allowance only applies to the secondary members of the roof structure and not to primary structural frame located within the roof or at the roof level [see Figure 601(1)]. This alternative is applicable for all occupancy classifications except Groups F-1, H, M and S-1. Figure 601(2) shows an example where a mezzanine reduces the clearance to the roof to less than 20 feet (6096 mm) for a portion of the total roof. Designs similar to Figure 601(2) do not comply with note b, and elimination of fire resistance is not allowed for any of the roof.
I cant find the justification for the bolded commentary sentence in the code. Anyone point to supporting the commentary requiring primary structural framing in the roof being excluded from the footnote b. allowance?
The footnote changed in 2018 footnote b. to table 601:
Except in Group F-1, H, M and S-1 occupancies, fire protection of structural members in roof construction shall not be required, including protection of primary structural frame members, roof framing and decking where every part of the roof construction is 20 feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
I don't have 2015 or 2018 commentary, but 2021 commentary is changed:
Note b applies to the construction of the roof and related secondary structural members in buildings of Types IA, IB, IIA, IIIA and VA construction. It allows these elements to be of unprotected construction when all parts of the roof construction are more than 20 feet (6096 mm) above any floor below. This allowance applies to both the primary and secondary members of the roof structure. This alternative is applicable for all occupancy classifications except Groups F-1, H, M and S.
Anyone disagree that all of the roof framing that meets the 20' - and yes all of the beam must be above 20', not just a portion of the beam - may be unprotected?
