Engineering Judgements for 2-Hour Fire Rating

Description: The U.S. Government is seeking information from manufacturers of thin-film intumescent structural fire protection products. Specifically, we request Engineering Judgements (EJs) for utilizing such products to achieve a 2-hour fire-resistance rating for steel structural members supporting a stair enclosure in a unique non-listed assembly application.

Scope of Work: The application entails protecting structural steel columns and beams within an existing facility. The floor/ceiling assembly, supported by the beams, does not have, nor require, a fire-resistance rating and consists of steel plate welded atop the beams. The underside of the steel plate is exposed. The topside of the steel plate on top of the beams is exposed in some areas and covered with vinyl flooring (VCT) in others.

Requirements:

Fire-Resistance Rating: An EJ for a 2-hour fire-resistance rating is sought solely for the supporting structural members. No fire-resistance rating is required for the steel plate floor/ceiling/roof.

Member Specifications:

Steel Columns: W14X90 wide flange and HSS8x8x5/8 columns.

Steel Beams: Ranging in size from W8x10 to W24x94.

Steel Plate Floors/Ceiling and Roof: Thicknesses of 1/4 inch and 5/8 inch.

Material Compatibility: The intumescent thin-film must be compatible with Amercoat 370 as a primer basecoat and PSX 700SG as a topcoat.

Product Specification: The intumescent fire-resistant material must be an intumescent thin-film coating; intumescent paints are not acceptable as per UFC 3-600-01, Section 7-4.2.1.