WB FD-P 8550 Series

Recessed Fire-Rated Aluminum Floor Hatches for Concrete or Tile

Sizes & Specifications

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Williams Brothers - WB FD-P 8550 Series Recessed Fire-Rated Aluminum Floor Hatches for Concrete or Tile

Recessed, Fire-Rated Aluminum Hatch Blends in Seamlessly with Concrete or Tile Floors!

The WB FD-P 8550 Series Recessed Aluminum Floor Hatch for Concrete or Tile is a rugged, recessed access door designed for new or existing openings in interior utility and general purpose applications. In subways, skyscrapers and everything in between, the WB FD incorporates the latest fire-resistant technology to protect floors above from fire below. Featuring a heavy-duty, 1/4″ reinforced aluminum cover and an aluminum/stainless steel thermal-break frame both with a mill finish, hatch is Warnock-Hersey tested for a 2 hour fire rating while a recess to accept concrete or tile enables this floor door to blend in seamlessly with the surrounding environment. In addition, door is reinforced for pedestrian traffic and can safely handle 150 psf loading.


  • Cover: 1/4″ Reinforced Aluminum Smooth Plate
  • Recess: 1″ Recess to Receive Concrete or 1/8″ for Tile (If recess is to be filled with concrete or other cast material, the door is furnished with anchor clips and wire mesh)
  • Frame: Thermal-break Frame with Aluminum Upper Frame and Stainless Steel Lower Frame
  • Finish: Mill finish – All Parts of the Frame in Contact with Concrete Have a Coating of Bituminous Paint
  • Latch: Two-point Slam Latch
  • Lock: Watertight 316 Stainless Steel Slamlock with Threaded Plug, Removable Outside Key, and Fixed Inside Handle (the slamlock latches onto a 316 SS striker plate that is bolted to the frame)
  • Hinge: Continuous 316 Stainless Steel Hinge, Flush with Cover Surface
  • Spring Actuators: Stainless Steel Compression Springs for Lift Assist Contained Within the Frame
  • Automatic Hold-open Arm and Closing Mechanism: 316 Stainless Steel Hold-open Arm Automatically Keeps the Cover in its Open/Upright Position at 90° – Incorporates Mechanism to Automatically Close and Latch the Cover When Heat Breaks a UL-listed 165° F Fusible Link
  • Hardware: 316 Stainless Steel Nuts and Bolts
  • Loading: 150 psf (732 kg/m2) Live Load
  • Fire-Rating: Warnock-Hersey Tested for a 2 Hour Fire Rating, Tested to NFPA 288 (ASTM E119)
  • Installation:Door is designed for Dry, Interior Locations Only


  • Construction: Steel
  • Custom Sizes: Available on Request


The WB FD-P 8550 fire-rated floor door is available in a variety of sizes including 24×24, 24×36, 30×30, 36×36, 36×48 and more. In addition, custom sizes are available upon request. Door features a flush lifting handle, stainless steel hinges, slam latch, stainless steel compression springs for lift assistance, and an automatic hold-open arm. Options include steel construction.

Manufactured for The Williams Brothers Corporation of America. MADE IN USA.