Combination Door Fire Rating Options

ASSA ABLOY Wood Doors believe in the importance of flexibility, allowing you to choose the door you want. The charts below set out our minimum dimensions for our combination doors as well as the maximum dimensions that will secure a UL- or Warnock Hersey-sponsored fire rating. In addition, we can usually construct doors that surpass the below dimensions and give them Construction Label Only (CLO) tags.

NOTE: combination doors with true divided lights are not available in 45-60-min fire ratings. A similar look is achieved using light kits and rails/mullions; accordingly, a particular component such as a light kit may change or add the requirements listed below. 

Dimension Ranges (Neutral Pressure)

Dimensions Non-Rated 20-Minute 45-Minute 60-Minute 90-Minute
Max door height 10' 9' 9' 9' 9'
Max door width 4' 4' 3'6" 3'6" 3'6"
Max door thickness 2 1/4" 2 1/4" 2 1/4" 2 1/4" 2 1/4"
Min door thickness 1 3/8" 1 3/4" 1 3/4" 1 3/4" 2 1/4"
Min stile height 9" 9" 9" 9" 9"
Min stile width 3" 5" 5" 5" 5"
Min mullion width 3" 3" 3" 3" 3"
Min rail length 9" 9" 9" 9" 9"
Min top rail width 3" 5" 5" 5" 5"
Min cross/lock rail width 3" 3" 3" 3" 3"
Min bottom rail width 3" 9 1/2" 9 1/2" 9 1/2" 9 1/2"
Min bar/munt width 1/2" 1" 1" 1" 1"
Max panel height 80" 93 1/2" 93 1/2" 93 1/2" 93 1/2"
Min panel height 6" 6" 6" 6" 6"
Max panel width 38" 38" 32" 32" 32"
Min panel width 6" 6" 6" 6" 6"
Min flat panel thickness 5/8" 5/8" 1 1/8"* 1 1/8"* 1 1/8"*
Min raised panel thickness 1 1/8" 1 1/8"** 1 1/8" 1 1/8" 1 1/8"

* 2 1/4" door thickness

** or 1 1/2" standard

Dimension Ranges (Positive Pressure)

Dimensions 20-Minute 45-Minute 60-Minute 90-Minute
Max door height 9' 8' 8' 9'
Max door width 4' 3' 3' 3'
Min door thickness 1 3/4" 1 3/4" 1 3/4" 2 1/4"

Custom Specification

If your needs require a slightly different look, we can handle it. Since all of our work is custom in nature, we have the flexibility to adjust to what you want. Our competitors can't promise that.