Standard Practice for Calculating Bending Strength Design Adjustment Factors for Fire-Retardant-Treated Plywood Roof Sheathing

Importancia y uso:

5.1 This practice establishes the procedure to determine adjustment factors that account for the isolated effects of fire-retardant treatment on plywood roof sheathing. These effects are established relative to performance of untreated plywood. This practice uses data from reference thermal-load cycles designed to simulate temperatures in sloped roofs of common design to evaluate products for 50 iterations.

5.2 This practice applies to material installed using construction practices recommended by the fire retardant chemical manufacturers that include avoiding exposure to precipitation, direct wetting, or regular condensation. This practice is not meant to apply to buildings with significantly different designs than those described in 1.3.

5.3 Test Method D5516 caused thermally induced strength losses in laboratory simulations within a reasonably short period. The environmental conditions used in the laboratory-activated chemical reactions that are considered to be similar to those occurring in the field. This assumption is the fundamental basis of this practice.

Subcomité:

D07.07

Referida por:

D6841-21, D5516-18

Volúmen:

04.10

Número ICS:

91.060.20 (Roofs)

Palabras clave:

design load values; fire retardant treatment; plywood; strength test;