That all-important door
Publication Date: Friday May 24, 1996

That all-important door

There's a good--no, great--reason for that solid garage door

by Lynn Comeskey

QWhat is the point of having a solid wood door in the wall between my garage and the rest of the house? Why is this door on a self-closing hinge? ABig Brother's bible, the Uniform Building Code, has decreed that your house will be as safe as possible. In the parlance of buildingdom, the garage and your living space are two different occupancies. The garage wall is an "occupancy separation."

I had to say all of that.

The code says that this occupancy separation must be a modified, one-hour wall. In theory, that means it would take one hour for a fire to burn through the wall. If a fire starts in an attached garage (which happens more frequently than one would think), this wall is a means of slowing down the fire to give the occupants more time to get out of the house.

A one-hour wall means installing 5/8-inch thick sheet rock on both sides of the wall. Any doors would have to be "rated" one-hour doors, and any other penetrations (such as a furnace duct) would have to have a self-closing mechanism or damper to prevent fire from spreading.

A rated door has a special tag attached indicating it is rated at one or more hours and is usually covered with solid core of wood or metal. One-hour walls are usually located in multiple-unit occupancies or commercial buildings.

The building code is full of exceptions.

One of these is the modified one-hour wall between the house and an attached garage. This wall is to have 5/8-inch sheet rock on the garage side (the other side will usually have 1/2-inch sheet rock). Any doors have to be a flush solid core, a minimum of 1 3/8-inch thick and be on a self-closing hinge.

Also, any electrical junction boxes must be metal and cannot be made of plastic. In the event there is living space over the garage, then the ceiling and the supporting walls would also have to be covered with 5/8-inch sheet rock.

This fire safety requirement is made for good reasons. There are far more garage fires than most homeowners think. Ask any building inspector or fireman: The garage is a dangerous place. Open flames in the furnace or water heater are the potential source.

Plus, there is plenty of fuel--gasoline, paint, firewood and paper. Garage fires are difficult to detect early because the homeowner is usually not there. Garage fires are hard to subdue because they are often filled with valuable possessions that are difficult to maneuver.

QWe have heard conflicting stories about smoke detectors. Where are we supposed to have them? ASmoke detectors are a good idea, but they are not required. There is, however, a state mandate stating that when any remodeling work is done on your house or a new house is built, smoke detectors must be installed in all halls and bedrooms. The building inspector will not pass the final inspection until she sees the smoke detectors.

Lynn Comeskey owns Mac & Lou Construction Co. in Palo Alto. His column on home improvement appears the fourth Friday of the month. Readers can write Comeskey care of the Palo Alto Weekly, P.O. Box 1610, Palo Alto, CA 94301.

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