Gasoline siding is a term used by firefighters to describe highly flammable house siding that burns like gasoline if it catches on fire. Gasoline siding refers specifically to asphalt felt siding, which is petroleum-based and catches on fire quickly and burns hot. The siding is rarely used in construction now because it is so flammable.
Gasoline siding was often made to look like brick. It was a popular material during the post-World War II housing boom, when returning GIs and a favorable market led to a massive upswing in housing construction. This boom made the siding a common feature in houses across the country, and can still be found on older homes.
Gasoline siding produces a special challenge for firefighters because of a phenomenon known as autoexposure: the siding allows the fire to climb up the outside walls of structure from floor to floor, spreading the fire much more rapidly than would happen in a house made out of a more fire-retardant material, such as brick. The siding will produce thick smoke when it burns, posing an additional danger for firefighters who may need to enter the building to stop the spread of flames. The siding is often cited by firefighting crews as a major contributing factor in the loss of homes that are built with the construction material. It has absolutely no fire-retardant properties.
Gasoline siding is made up of felt, created from cellulose fibers, rags and wood; asphalt made from petroleum; stabilizers such as marble, sandstone or talc; surfacing materials, such as mica; granules, available in a variety of colors and made from crushed slate, granite or marble; and gravel or marble chips, which add the final layer to the siding. It is sold as shingles or as a single roll for covering large surfaces. The surface of the siding is embossed so that it looks like bricks. With time, the siding will dry out and become brittle, leading to cracking, chipping, erosion and general deterioration. The same material was also used for constructing roofs.
Although this siding is not used much anymore, it is a good idea to check for it as new siding may have been placed over existing gasoline siding. If you can't identify it by sight, a home inspector will be able to check for it and make sure that it is not sandwiched underneath newer siding. Homeowners are not required to replace existing gasoline siding, but should be aware of the dangers posed by the material.