South Shore Millwork® offers paint-grade and stain-grade doors in 20- through 90-minute fire ratings.
South Shore Millwork fire door offering
|20-minute MDF||20-minute Wood||45- and 60-minute MDF/wood||90-minute MDF/wood|
|Thickness||1-3/4″ minimum||1-3/4″ minimum||1-3/4″ minimum||1-3/4″ minimum|
|Maximum width single||4’0″ **||4’0″ **||3’6″||3’6″|
|Maximum width pair||8’0″||8’0″||7’0||7’0″|
|Fire glass max. area||3,145 sq. inches||3,145 sq. inches||N/A||N/A|
|Standards||ASTM E-152, NFPA 80, NFPA 252, UL10B, UL10C|
* Some door styles and panel profiles are not available in all fire ratings.
** Doors over 3’6″ not covered by South Shore Millwork warranty
Positive Pressure Fire Door Overview
All South Shore Millwork fire doors comply with the following standards: UBC7-2-1997, UL 10-C (positive pressure), NFPA 252 (1995), ASTM-252, and UL10-B (neutral pressure).
The standards for the design, testing and certification of fire rated openings changed when the International Building Code adopted the 1997 Uniform Building Code (UBC) 7-2-1997. With the adoption of this code came the requirements for fire rated openings to be tested under positive pressure in accordance with UL 10-C. Positive pressure testing of fire rated openings more accurately reflects the conditions of a real fire. However, the change from neutral pressure to positive pressure significantly impacted the dynamics of the door and hardware which is located above the 40″ neutral pressure plane.
In order to successfully pass a fire test under the new positive pressure requirements, it is necessary for wood door manufacturers to provide doors with listed and approved intumescent seals or gasketing. The WDMA (Wood Door Manufacturers Association) describes positive pressure openings in two categories, Category A and Category B.
Category “A” doors have sealing systems built into the door edges and therefore do not require any additional edge sealing systems between the door and frame. The sealing systems can either be visible or concealed within the edge of the door. All Positive Pressure South Shore Millwork Fire Doors are manufactured as Category “A” with concealed sealing systems.
Category “B” doors do not have sealing systems built into the door edges. These doors do require additional listed and approved edge sealing systems between the door and frame. These sealing systems are generally surface applied to the door and/or frame. Category “G” describes edge sealing systems which meet this listing requirement. In some cases, Category “G” sealing systems might be required on the meeting stiles of pairs of Category “A” doors.
Smoke Seal Labels
In addition to standard fire ratings (A/3 hour, B/90 or 60 minute, C/45 minute and 20 minute), some positive pressure doors may also be required to carry a smoke seal (“S”) label. In these cases, the doors and frames will bear two labels. One indicating the fire rating (fire label) in minutes and the other indicating the opening is smoke rated (smoke label). Category “H” describes sealing systems for doors and frames to meet this listing requirement.
Consult NFPA 80 to review requirements for the installation of fire doors and windows.
Please note: it is the responsibility of the door distributor to inform the manufacturers of what the code requirements are for the fire doors and frames on a given project.