One of the biggest fears for many homeowners is fire. Smoke alarms are currently required in all homes to provide warning in case of fire, and building codes in most jurisdictions require self-closing fire doors from an attached garage to the interior of a house. If you should have to replace this door, or if you want to install additional fire doors in the interior of your home for extra safety, here are a few things you should know.

Fire Door Ratings

The National Fire Protection Association rates fire doors in time intervals. Ratings are:

• 20 minutes
• 45 minutes
• 60 minutes
• 90 minutes
• 180 minutes

Residential fire doors are typically 20-minute doors, which means they'll give your family an extra 20 minutes to escape before a fire breaks through the door/wall fire barrier. Fire doors are rated at three-quarters of the wall rating.

Fire Door Materials

Typical residential fire doors are made of fiberglass or wood with a metal core. Glass panels or "lights" are also available in fire doors, using quarter-inch wire glass or ceramic glass. Both the fire door's material and thickness are considered in the rating. The Underwriters' Laboratories (UL) tests and approves fire doors. When fire doors are installed, they must seal tightly into the frame to prevent flames from coming through.

When considering interior fire doors, place them between your sleeping areas and the places a fire is most likely to break out; kitchen, basement, or utility room. Given the fire resistance rating of walls in typical residential construction, a 20-minute door will be sufficient in nearly all cases. Make sure all fire doors are self-closing, because an open fire door is of no use as a fire barrier.

If you're considering installing a fire door, it's worth your while to consider all these factors before installation day. That way, you know your fire door is another line of defense between a fire and your family.