What about asbestos in and around your house?

Sunset, Sept, 1988

6. Air-cell insulation. Are your metal ducts covered with insulation made up of the material pictured below left? (To distinguish it from sheeting insulation-item 10-look for ridges on the surface.) It's 35 to 90 percent asbestos, and should be professionally removed if torn or flaking. (For more on ducts, see item 2.)

7. Asbestos-backed linoleum. If you pull up linoleum sheet flooring that has asbestos backing or adhesive, you can be exposed to asbestos. The greatest danger is in sanding down such a floor or the adhesive. One alternative is to cover the old floor with particle board before installing a new one, as shown on page 85. An undisturbed floor should pose no hazard.

8. Fuse box liners, stove door gaskets. Old wooden fuse boxes may have a lining of up to 90 percent asbestos-a problem if it's frayed or damaged.

The doors of some wood-burning stoves, older gas and electric stoves, older furnaces, and hobby kilns may have gaskets that contain asbestos. These gaskets look like whitish gray flattened rope (fiberglass gaskets look similar but have slightly more sheen). If you suspect asbestos, write to the manufacturer for information, giving model and serial number. If the material is asbestos and is deteriorating, consider having it removed.

9. Textured acoustical ceilings. These "cottage cheese" ceilings tend not to be a problem unless damaged-by a roof leak or a child's bouncing ball, for example, They usually contain from less than 1 percent to 5 percent asbestos, but some may have up to 40 percent.

Don't disturb these ceilings. For example, make sure drapery movement doesn't rub off the material, and don't add devices such as plant hooks. Instead of sweeping to remove cobwebs, use a damp paper towel and seal towel and debris in a plastic bag before discarding. Painting or spraying these ceilings can also release fibers.

10. "Sheeting" insulation. Heater ducts may be covered with a gray or grayish white papery material that looks like the air-cell insulation pictured on page 86, but without ridges. This insulating wrap contains 40 to 90 percent asbestos; it's a problem only if disturbed or damaged. (See items 2 and 6 for more on ducts.)

11. Pad under furnace. Your furnace may stand on a pad containing asbestos or have an asbestos lining in the bottom. If it sticks out where it can be damaged, or if it's deteriorating, it should be removed.

12. Joint compounds and patching plaster. Until about 1979, many of these products contained 3 to 10 percent asbestos. They don't pose a problem unless you disturb them during remodeling, or sand them.

13. Acoustical ceiling overspray in ducts. Examine heater ducts for "cottagecheese" overspray. If it's deteriorating, it can release some fibers. (See item 9.)

14. Artificial concrete-asbestos logs. These gas-fireplace logs (20 to 45 percent asbestos) usually don't release asbestos unless they are broken and disintegrating. Use a mirror to check the back of the log.

15. Asbestos-insulated wiring. In older homes, some knob-and-tube wiring may have an insulating layer of material that is 50 to 60 percent asbestos. Look for a white coating on the wire, encased in a black fabric outer covering. This may release fibers if cut or pulled out. 16. Vinyl-asbestos floor tiles. Most vinyl floor tiles-even those sold now contain about 20 percent asbestos.