If you own a business in the Greater Los Angeles area, then there is no doubt that you are well-acquainted with Regulation 4. Regulation 4 is the policy from the Los Angeles Fire Department requiring certain doors in certain types of buildings to meet very specific safety standards. At Barr Commercial Door, which serves the Los Angeles area, there are both fire-safe and regular hollow doors.
Hollow doors are not just for the prevention of the spread of fire and smoke.
They can be sound-proof. They can be used for insulation or energy conservation purposes. They can even be bullet-proof. Metal hollow doors are actually filled with a variety of fillers, depending on your needs. The fillers come in three categories: honey-combed cores, steel-stiffened cores, and polystyrene or polyurethane cores. Honeycomb core filled doors may be used for interior or exterior doors. Honeycomb cores, because of their unique structure, are good for sound-proofing and insulation. During compression testing, honeycomb cores were found to be able to withstand more than 5,000 lbs. of weight per square foot. One square foot of the honeycomb filler only weighs three ounces. Steel-stiffened cores are mainly exterior doors. They are rigid, with a 20 gage or higher steel used for strength and security. These doors are very strong. Fiberglass insulation is primarily used to fill in the spaces in the steel-stiffened core. Polystyrene and polyurethane cores are used as insulators against an extreme of heat/cold. These doors are good in stairwells and as fire doors. All hollow metal doors are (UL) labeled for inspection purposes. Polyurethane core doors usually do not pass the inspections used to test for positive pressure requirements. The positive pressure test determines if a door will resist and help fan out the expansion and weight of gasses that occur during a fire. These doors are best with extreme temperatures such as seen in colder climates. Honeycomb, steel-stiffened and polystyrene doors will usually pass the positive pressure test. Hollow metal doors are very versatile, being used for a large variety of commercial businesses and medical and school facilities.
Hollow metal doors are made of galvanized steel.
The sheet metal undergoes a shearing process to cut it down to size. They come in 16, 18, and 20 gauges. They are fire-rated, insulated, and may be interior or exterior doors. Depending on what their cores are filled with, the weights of the doors vary from 97 lbs. to 136 lbs. Doors are Regulation 4 certified. Doors are used for a wide variety of purposes. Airlines may use a steel-stiffened core filled hollow metal door for its strength and durability. A hospital may use a polystyrene Regulation 4 door to meet its fire regulations. Commercial warehouse and service doors may use a polyurethane core door for exterior doors that need to be resistant to extreme cold. Barr Commercial Doors come with Regulation 4 ratings in order to stay in compliance with the annual greater Los Angeles and Orange County fire regulations.