Door cores


When selecting a core, you should consider the following aspects:



Temperature rise fire doors protect people escaping from a building in a fire. For example, if the fire is on the 7th floor of a building, people coming down from the upper floors will be protected from heat and fire in the stairwell by a stairwell door with a temperature rise core.

This protection could be 90 minutes for fire rating, and a temperature rise of 450°F in 30 minutes, on the unexposed face of the door. This level of temperature may sound particularly high, but as long as people do not make contact with the door, they will be safe to escape in the stairwell. Note that 250°F doors also exist with a mineral core.



References:

NFPA 252: Standard Methods of Fire Tests of Door Assemblies.
IBC 2003: International Building Code.


Products & Solutions:

de La Fontaine Industries offers the following options:



Honeycomb.

Info: 1" (25 mm) cells with phenolic resin.
Recommended application: Standard interior openings.
Benefit: Less stress on hinges because of light core.
Limitations: Limited insulating factor, not recommended for exterior doors.
Comment: The total recycled content is 40%.  This includes 100% of post-consumer content and 60% of new material.



Polystyrene block.

Info: Isolation factor: R value = 7.03 (hr °F-sq/ft)/BTU per ASTM E-90
Recommended application: Exterior openings.
Benefits: Good insulating factor. Less stress on hinges because of light core.
Limitation: Not the best option for extremely cold areas.
Comment: Excellent bonding with the door skins.  The total recycled content is 69.4 %.  This includes 33.6 % post-consumer content and 35.8 % post-industrial content.



Urethane block.

Info: Isolation factor: R value = 8.66 (hr °F-sq/ft)/BTU per ASTM E-90.
Recommended applications: Exterior openings in extremely cold areas. Cold storage.
Benefits: Excellent insulating factor. Less stress on hinges because of light core.
Limitation: Approximately 3 times the price of polystyrene core.
Comments: Slight decrease of insulating performance over the years. Issues with Environmental Protection Agency (EPA) when doors are discarded.


Temperature rise.

Info: Available in 250, 450 and 650°F temperature rise in 30 minutes.
Recommended applications: Vertical exits (stairwells), passage-ways.
Benefit: Protect people from heat and fire when escaping from a building in a fire.
Limitation: More stress on hinges because of heavier weight.
Comments: May not be required in buildings equipped with sprinkler systems. Refer to your Local Building Code requirements.


Steel stiffened door.

Info: 18-gauge (0.044"/1.1 mm) stiffeners 4" (102 mm)  to 6" (152 mm) apart, center to center. Polystyrene or urethane between stiffeners.
Recommended applications: High security areas. Detention facilities.
Benefit: Adds strength to the door.
Limitation: More stress on hinges because of heavier weight.
Comment: Steel stiffeners compromise the insulating factor of the door.