In the UL standard, 20 minutes is the lowest rating and most common choice for a wood fire door. Though people think 20 minutes is a pretty short time for a fire emergency, it does save much more people than it’s regarded.
The door is usually used for interior living rooms while rarely being used for entrance door. When a fire emergency happens, smoke is always much more dangerous than fire itself cause in the most of fire emergencies people get killed by smoke instead of burned. A 20 minutes UL labeled wood fire door is tested in a 1000℃ flame for 20 minutes, whereafter the inspectors will use a water torch to damp down the fire. This process will last around 5-10 minutes and the test will succeed only if the door is not broken or fallen down. So when search for 20 minutes wood fire door, please take a look at the certificate of supplier whether they have passed positive pressure test.
Asico Door offers originally UL tested wood fire doors 20 minutes which complys to:
• UL 10B, Fire Tests of Door Assemblies (neutral or negative pressure)
• UL 10C, Positive Fire Pressure Tests of Door Assemblies
• NFPA 252, Standard Methods of Fire Tests of Door Assemblies
Asico 20 minutes wood fire door specifications:
20-Minute Positive Pressure Category "B" MDF & Wood Doors
20-Minute Neutral Pressure MDF & Wood Doors
20 minute single opening
4'0' x 10'0'(1219mm x 3048mm) maximum allowable opening
20 minute double opening
8'0' x 8'0'(2438mm x 2438mm) with astragal maximum allowable opening
Raised Panel 1 1/8" minimum
Flat Panel 11/16" minimum
Maximum Lite Size 38" x 82 3/4"
Maximum Lite Area 3.145 in²
Stile 5" minimum
Top Rail 5" minimum
Bottom Rail 8 1/4" minimum
Intermediate Stile/Rail 2" minimum
A 20 minutes wood fire door can be made into flush or paneled type which means it has more decorative propertities. What’s more, both solid wood frame and hollow metal frame are capable of a 20 minutes rating door slab.
Solid Hardwood Frame
--Asico Production Line