FIRE RATINGS

Hambro brings you one of the finest fire rated structural floor systems in the world.

There are many accepted methods to achieve satisfactory fire protection of the Hambro floor system. Extensive fire testing has been performed by Underwriters Laboratories (UL) resulting in many milestones and again proving the superior performance of the Hambro system. The full scale fire tests are performed while the system is loaded to its full design capacity and the results are overwhelming.

Gypsum drywall ceiling membranes installed directly under Hambro joists are generally used in residential construction. They are economical, aesthetically pleasing and can safely accommodate integrated sub-systems, recessed light fixtures and ventilating units without impairing their fire rating capabilities. UL Design No. G-524 has been the most popular Hambro rating for residential applications due to its enormous flexibility. For each 100 square feet of ceiling area, it allows unprotected plenum ceiling penetrations up to 256 square inches for 1 hour, 196 square inches for 1.5 hours and 100 square inches for 2 hours. Always consult the latest listing published before detailing.

Accessible ceiling panels commonly referred to as "lay-in  ceiling tiles are generally used in office, commercial and institutional construction. These removable panels allow access to the ceiling plenum for alterations to mechanical or electrical equipment.

Insulating the Hambro joist by sprayed on fireproofing is another accepted method of fire protection.

The following UL Designs all incorporate Hambro joists. Always check your UL Directory for the latest updating of these listings and applicable building codes before detailing ceiling construction.

Gypsum Board Membrane:

G-524, G-525,

Suspended or Lay-in Ceiling:

G-003, G-213, G-222, G-227, G-228, G-229, G-236, G-243

Sprayed-on Fireproofing:

G-702, G-802, G-803

The following are UL Ratings when designing with the Hambro floor system.