Sun Mountain is certified to both manufacture and pre-hang wooden fire doors. Twenty-minute, 45-minute, 60-minute, and 90-minute fire-resistance ratings are available. All of Sun Mountain’s fire-rated doors meet UL 10C/NFPA 252 for both positive pressure and negative pressure test requirements. In addition, all of Sun Mountain’s fire-rated doors are Category “A,” meaning no additional edge-sealing system is required on the door jambs. All doors are eligible to bear the “S” (for Smoke & Draft Control assemblies) if a listed “Category H–Smoke & Draft Control Gasket” has been applied to the assembly.
Specifications and limitations for each rating are as follows:
20-MINUTE FIRE DOORS
For 20-minute rated fire doors, the maximum size available is 3′ 6″ width x 8′ 0″ height for a single door, and 7′ 0″ x 8′ 0″ for a double door. Twenty-minute rated doors with glass are available, using a special fire-rated clear glass (called “FireLite®”). The total glass size must be no more than 1,296 square inches. Mortised flush bolts and automatic door bottoms are also available.
Twenty-minute fire-rated jambs are available in most wood species. The jamb width must be at least 4-9/16″ and will also qualify for a positive pressure fire rating with hose stream.
45-MINUTE FIRE DOORS
The maximum size available for 45-minute rated fire doors is 3′ 6″ x 8′ 0″ for single doors, and 7′ 0″ x 8′ 0″ for double doors. Doors with glass are available, with the total glass size no more than 1,248 square inches. Fire-rated wood jambs are available on single doors only, with jambs at least 4-9/16″ wide. Steel fire-rated jambs are required for double doors. Mortised flush bolts are allowed. Mortised automatic door bottoms are not available on 45-minute rated fire doors.
60-MINUTE FIRE DOORS
Sixty-minute rated fire doors can be a maximum size of 3′ 6″ x 8′ 0″ for single doors, and 7′ 0″ x 8′ 0″ for double doors. Doors with glass are available, with the total glass size no more than 100 square inches. Wood fire-rated jambs are available on single doors only, and must be at least 4-9/16″ wide. Steel jambs are required for double door applications. Mortised flush bolts are allowed, but mortised automatic door bottoms are not available.
90-MINUTE FIRE DOORS
Ninety-minute rated fire doors are available in sizes up to 3′ 6″ x 8′ 0″ for single doors. Double doors with this rating are not available. Doors with glass are available, with total glass size no more than 100 square inches. Steel jambs are required for all 90-minute rated doors. Mortised flush bolts are available. Mortised automatic door bottoms are not available.
INSTALLATION AND ON-SITE MODIFICATIONS OF FIRE DOORS
Fire-rated doors must be installed with no more than 1/8″ clearance (or “reveal”) between the door and jamb. Dutch doors, doors with transoms, and double doors must be installed with no more than 1/8″ clearance between leaves.
Trimming for height may be done on the bottom rail of wooden fire-rated doors, with trimming limited to no more than 3/4″. Trimming for height is not allowed for steel fire doors. Surface mounted hardware must be attached with throughbolts unless interior blocking of the door is provided. The manufacturer’s fire-rating label may not be removed, covered, or painted over.
Per NFPA 80, jobsite modifications to fire-rated door jambs are restricted to the following:
- Mortising circular or rectangular function holes for latch bolts
- Prepping around function holes for strike plates
- Installing gasketing or seals to the jamb, as required
In addition, the bottom of each jamb leg may be trimmed to fit the rough opening, as needed.