Cable trays and busways at floor level or at slab penetrations shall have a waterstop no less than 50 mm in height. At slab penetrations, provide 20–30 mm of firestopping and install a fire-support plate at the top. Cover plates should be square, of consistent suitable. The following charts give the number of 3M pillows needed to completely firestop an opening that cable tray passes through. UL Listed Systems Concrete Wall - C-AJ-4056 3 HR F-Rating, 3/4 HR T-Rating Gypsum. This document outlines the key requirements for cable tray layout, installation, and fireproofing in industrial and commercial environments. This includes checking their flammability, smoke production, toxic gas emissions, and ability to block heat and fire. Why Does. RECOMENDATIONS BE APPROX. 6" LARGER THAN THE OUTSIDE DIM. OF CABLE TRAY FIRE SEALANT BAGS (SEE NOTE #1) BAGS SHALL BE: GRACE CONSTRUCTION PRODUCTS KBS SEALBAGS OR 3M FIRE BARRIER PILLOWS. INSTALL BAGS PER MANUFACTURERS INSTRUCTIONS TO ACHIEVE UL CLASSIFIED FIRE RATING EQUAL TO OR GREATER THAN FIRE. Cables, cable bundles, conduits, bundles of conduits, empty pipes, cable trays and cable ladders may also pass through penetration seals in walls and floors and should be taken into consideration during all phases of design and application.