Appeal 34768

2022 OSSC 703.3 and 704.3

703.3 Alternative Methods for Determining Fire Resistance. The application of any of the alternative methods listed in this section shall be based on the fire exposure and acceptance criteria specified in ASTM E 119 or UL 263.

704.4 Protection of primary structural frame other than columns. Members of the primary structural frame other than columns that are required to have protection to achieve a fire-resistance rating and support more than two floors or one floor and roof, or support a load-bearing wall or a no-load-bearing wall more than two stories high, shall be provided individual encasement protection by protecting them on all sides for the full length, including connections to other structural members, with materials having the required fire-resistance rating.

To provide 1 or 2-hour fire rated protection for steel plates that compose the steel column cap / bucket assembly.

The proposed design consists of 1/4” steel plates that compose a column cap that supports Glu-lam beams and are connected to a 1 or 2-hour fire rated HSS column. The steel plates are to be protected by intumescent paint with the thickness required by the manufacturer to provide 1 or 2-hour fire rated protection. See (Exhibit 1) attached plan with steel column cap locations and details for reference. The proposed design is equivalent to the UL-listed assembly BXUV.N657 to achieve a 1 or 2-hour fire-rated protection (Exhibit 2). See also Project Submittal (Exhibit 3) which describes the fire resistance capacity of Intumescent Coating intended for use.

RECONSIDERATION TEXT:
The proposed design consists of 1/4” steel plates that compose an HSS steel bucket that supports Glu-lam beams and are connected to a 1 or 2-hour fire rated HSS column, as well as a steel column cap that attaches to the underside of the floor double top 2x wood plate and wood sheathing above. The steel plates are to be protected by intumescent paint with the thickness required by the manufacturer to provide 1 or 2-hour fire rated protection. See (Exhibit 4) PDF for summary description of proposed assembly, detail steel shop drawings of all locations to receive intumescent paint called out with a red circle, the G1.04 sheet highlighting the locations in plan, Contego intumescent paint product data, an application guide for paint, BXUV.N644 fire resistance rating showing ANSI/UL 263 details, and approved primers and topcoats.

As a primary structural member, the steel column cap assemblies are required to have a 1 or 2-Hour fire rating per Table 601 of the OSSC. The steel plates are protected by intumescent paint to provide 1 or 2-hour fire-resistance, equivalent to the protection provided by the tested UL assembly Y657. The proposed design for the steel plates with intumescent paint protection exceed/achieves the required 1 or 2-hour fire-resistance (as required by the referenced detail).

RECONSIDERATION TEXT:
As a primary structural member, the steel column bucket and top cap are required to have a 1 or 2-Hour fire rating per Table 601 of the OSSC. The steel plates are protected by intumescent paint to provide 1 or 2-hour fire-resistance, as shown by the provided intumescent paint product data and testing in (Exhibit 4). The proposed design for the steel plates with intumescent paint protection exceed/achieves the required 1 or 2-hour fire-resistance.