The rough opening (R) is 2″ wide by 1″ high.
The rough opening (RO) is 2-1/2″ wide by 2-1/2″ high.
The throat size is determined by the wall thickness.
Common wall compositions and their throat size:
- 2-1/2” metal stud, 1 layer of 5/8” sheetrock both sides: 3-3/4”
- 3-5/8” metal stud, 1 layer of 5/8” sheetrock both sides: 4-7/8”
- 3-5/8” metal stud, 2 layers of 5/8” sheetrock both sides: 6-1/8”
- 6” metal stud, 1 layer of 5/8” sheetrock both sides: 7-1/4”
- 8” block: 7-3/4″
- Class A (3 hour) – openings in firewalls that divide a single building into fire areas.
- Class B (1-1/2 hour) – openings in enclosures of vertical shafts and stairwells through buildings and in 2-hour rated partitions providing horizontal fire separations.
- Class C (3/4 hour) – openings in walls or partitions between rooms and corridors having a fire resistance rating of 1 hour or less.
- Class D (1-1/2 hour) – openings in exterior walls subject to severe fire exposure from outside the building.
- Class E (3/4 hour) – openings in exterior walls subject to light to moderate fire exposure from outside the building.
It depends on the rating. All glass used in fire-rated doors must be listed glass and be either ¾” wire or other listed material. Basic guidelines:
- 20 minute fire-rated door – 1,296 sq. in. per lite
- 3/4 hour fire-rated door – 1,296 sq. in. per lite
- 1-1/2 hour fire-rated door – 100 sq. in. per lite
- 3-hour flush door, no glass – per manuf. requirements
Rotary sliced or rotary cut follows a log’s annual growth rings, providing a bold, random appearance.
Plain sliced or flat cut is sliced parallel to the center of a log, creating a cathedral
or straight grain pattern, which is ideally suited for matching doors and wall patterns.
Quarter cutting produces a series of straight grained stripes that vary in width from species to species, and can also produce flake patterns, especially in oak woods.