Wood Debris in Soil
In some cases the base of the exterior wood siding is in contact with the ground, so that the foundation wall is not visible. This is a poor construction practice but unfortunately is fairly common and usually occurs during final grading and landscaping. The base of the wood siding should terminate at least 6 inches above the finished grade. Redwood or cedar exterior siding is often used. Both types of siding are resistant to termite attack and rot. However, it is important to understand that they are not immune to attack and might eventually succumb. If the base of the siding is in contact with the ground, probe it with an ice pick or a screwdriver. If the wood has not been attacked by rot, termites, or other wood-destroying insects, your probe will not penetrate much beyond the surface. If the probe penetrates the wood deeply, the wood has been attacked. To determine the cause for the deterioration, it is necessary to break open a section and look at the condition of the wood. Caution: Do not proceed beyond the probing without consent of the homeowner; in fact, it would be wise to obtain the homeowner’s consent for the probing.
A section of termite-damaged wood reveals galleries (channels) that run parallel with the grain. (See FIG. 8-6.) Termites attack the softer portion of the wood grown during the spring and not the denser summer wood. The channels will not look polished, as they do with carpenter ants. Portions will be lined with grayish specks that consist of excrement and earth. Deteriorated wood could be the result of a combination of causes such as rot, termites, and carpenter ants. You should become familiar with the telltale signs. If you are not certain of the cause, have the wood evaluated by a professional. The appearance of wood damaged by carpenter ants, powder-post beetles, and rot will be discussed in their respective sections.
As you walk around the outside of the house, probe the attached wood trim, posts, and framing members that are on or close to the ground. Specifically probe garage door frames, basement or lower-level window frames, step stringers, deck posts, and the entry-door riser. Termite activity is of concern only when it is found in the house or in an attached structure such as a garage or deck. If you find termite damage or shelter tubes on a fence post in the yard (FIG. 8-7) or in a piece of wood debris on the ground in the yard, all that means is that those pieces of wood have had termite infestation. It does not mean that the house is infested with termites and should be treated.
After checking the outside of the house, the next place to look is in the crawl space beneath the house or porch. (Not all houses have a crawl space, in which case this step is omitted.) If the access to the crawl space is from the interior, it should be checked as part of the interior termite inspection. In the crawl space, probe the sills and headers for termite damage. Also check the first 15 inches of each joist that rests on the sill or foundation. As you move around in the crawl space, look for termite shelter tubes on the foundation walls and piers. Sometimes the shelter tubes can be spotted between double joists (two joists nailed together, used to provide additional support for a heavy load). While in the crawl space, note any items of wood storage, remembering that they are vulnerable to infestation.
The interior inspection for subterranean termites is generally conducted in the basement and crawl space. If the basement is finished so that there are no exposed sections of foundation wall or wood framing, a thorough inspection cannot be performed, even by a professional. There are, however, some sections more vulnerable to termite attack than others, such as sill plates, headers, and joists below grade or adjacent to a dirt-filled, cement-covered patio. If the ceiling is covered with suspended tiles, the tiles can be lifted or moved to expose the wood framing. If there are no accessible areas, termite activity will have to be determined by a swarm or exterior inspection. In areas where termite infestation is heavy, such as the South and Southwest, a termite inspection should be performed every year. In other areas, a biannual inspection is adequate.
When the basement is unfinished, the wood framing on top of the foundation wall should be inspected by probing as described for the exterior crawl space. Also look for termite shelter tubes. You might find a tube that appears to start in the center of the foundation wall. Actually, the tube is connected to the earth through a small crack in the wall at that point. As previously mentioned, termites can work their way through cracks as small as 1⁄32 inch. While in the basement, pay particular attention to the area around the furnace/boiler and pipes through the foundation or floor slab. Often activity is discovered in these areas.
Homes built on a slab without a basement or crawl space are also vulnerable to attack by termites. Because there are generally no areas with exposed beams or foundation, detecting termites is quite difficult unless the infestation has advanced to the point where shelter tubes are visible in the finished rooms. When inspecting a slab house, look for soft spots in the baseboard trim along the exterior wall. Also check for shelter tubes around openings in the floor slab, such as around plumbing or heating pipes.