Type NB roof hatches, 30" x 54" (762mm x 1372mm), are ideal for installations where frequent use may be expected. Permits easier movement of maintenance personnel, tools and equipment. Available in galvanized steel, aluminum, or stainless steel construction.
Material (select one): Steel: Cover and frame are 14 gauge (2 mm) G-90 paint bond galvanized steel. Aluminum: Cover and frame are 11 gauge (2.3 mm) aluminum. Stainless Steel: Cover and frame are 14 gauge (2 mm) type 304 stainless steel
Cover: Brakeformed, hollow-metal design with 1" (25 mm) concealed fiberglass insulation, 3" (76 mm) beaded, overlapping flange, fully welded at corners, and internally reinforced for 40 psf (195 kg/m2) live load.
Curb: 12" (305 mm) in height with integral capflashing, 1" (25 mm) fiberboard insulation, fully welded at corners, and 3-1/2" (89 mm) mounting flange with 7/16" holes (11 mm) provided for securing frame to the roof deck.
Gasket: Extruded EPDM rubber gasket permanently adhered to cover.
Hinges: Heavy-duty pintle hinges with 3/8" (9 mm) Type 316 stainless steel hinge pins.
Latch: Slam latch with interior and exterior turn handles and padlock hasps. (For Type NB-20HZ and NB-50HZ Miami-Dade County approved models: Specify enclosed two-point spring latch with interior and exterior turn handles and padlock hasps)
Lift Assistance: Compression spring operators enclosed in telescopic tubes. Automatic hold-open arm with grip handle release.
Performance Ratings: Complies with UL 790 Class A (burning brand test).
Finish: Steel: Alkyd base red oxide primer. Aluminum: Mill Finish. Stainless Steel: Type 304 stainless steel with bead blast finish
Hardware: Steel: Engineered composite compression spring tubes and steel compression springs packed in grease. All other hardware is zinc plated/chromate sealed. Aluminum: Engineered composite compression spring tubes and steel compression springs packed in grease.Type 316 Stainless steel hinges. All other hardware is zinc plated/chromate sealed. Stainless Steel: Type 316 stainless steel.