10. Rotted Beams, Joists, and Sills "The most common signs of rot are stained or soft wood, the presence of black or yellow fungus, insects or, in the case of painted wood, a soft depression under the surface of the paint," says Mark Cramer, president of the American Society of Home Inspectors in Des Plaines, Illinois. To determine the extent of the damage, probe the area with an ice pick or screwdriver to check for soft or spongy wood. If the rot damage exceeds 10 to 15 percent of the beam, it usually requires a structural repair. Using a pressure-treated replacement will prevent the problem from reoccurring, but in most cases, an epoxy patch is a faster, less expensive fix. Most repair kits contain a consolidant, which hardens any questionable wood, and a two-part epoxy. When properly mixed and used with the appropriate fillers, structural epoxies are stronger than the original wood.