Checklist for Environmentally Responsible Control of Wood-Destroying Insects
NOTE: Most of the strategies below apply to all wood-destroying insects. For pests other than termites, common-sense design and construction practices represent the first line of defense.Site selection
Use particular caution when building on heavily wooded sites. Termite and carpenter ant infestations are more likely on building sites that are carved out of the woods. Avoid sites with extensive buried organic matter. Buried wood is an ideal food source for subterranean termites.Building Design
Design detailing that will avoid moisture problems. Termites are attracted to moisture, and carpenter ants prefer rotted wood for building nesting cavities. Avoiding moisture problems in buildings is a very important strategy in pest insect control. For example: provide adequate eave and gable overhangs; protect entryways; provide quality flashing details; provide gutters; and incorporate exhaust ventilation at moisture sources (kitchens and bathrooms). Specify high-performance windows . Condensation on windows can be a significant source of moisture damage in buildings, which attracts or provides habitat for insect pests. Incorporate a termite sand barrier. Termite sand barriers have a fairly high success rate in areas where they have been used: primarily Hawaii, but also California and Texas. Termites are unable to tunnel through the coarse sand because the grains are too large to move and too small to crawl between. Incorporate Termi-Mesh. Termi-Mesh, used successfully in Australia for more than 10 years, is now being used in Hawaii and Florida with a very high success rate. Specify SmartGuard wood building components. Borate-treated wood products are resistant to termites, carpenter ants, and powderpost beetles. While expensive, this new building system is likely to catch on in the “Bug Belt”. If salvaged wood products are being specified, check the supplier’s program for dealing with insect threat. Professional wood salvage operations will have inspection and treatment protocols based on the type of wood product, species of wood, and source/destination.Construction
Provide careful construction detailing to avoid moisture problems. Avoiding moisture problems (and the resultant risk of insect damage) involves not only designing appropriate construction details, but also carrying them out. Ensure that flashing, drip edge, and drip-cap details are properly installed, and slope ground away from the building to provide surface-water drainage. Maintain dry storage of framing materials and avoid long-term site storage, particularly on wooded sites. Kiln-drying eradicates most insects, but wood materials stored on-site for long periods may become infested or absorb enough moisture to become susceptible to infestation. Carefully inspect salvaged building materials for evidence of infestation. The use of salvaged framing timbers or other wood building components comes with some level of insect risk. Careful inspection prior to installation is very important. Remove plants from the immediate building perimeter or overhanging the building. Ground covers, shrubs, and trees in contact with a building can provide a pathway for insect entry. If the building has a specialized barrier, such as termite-barrier sand or Termi-Mesh, these plantings may allow insects to circumvent the barrier. (Note that this issue may need to be weighed against the cooling-load-avoidance benefit of vegetation around a building.) Do not bury wood waste or other cellulosic materials on site or use as fill. It’s not uncommon for scrap lumber to end up around founda-tions or in porch crawl spaces, practices to be strictly avoided.Building operation
Keep plants away from contact with building. As a component of ongoing landscaping, make sure that vegetation is kept away from the immediate building perimeter or direct contact with the building. Operate building to avoid moisture problems. Exhaust fans should be used regularly; avoid use of humidifiers unless absolutely necessary (dry air is more often an indicator of a leaky building); never store firewood indoors; keep gutters and downspouts clean to prevent clogging; make sure that splash blocks under downspouts slope away from house. Avoid bridging the termite barrier . Careless habits can allow termites to bypass even the best termite barrier—as might occur, for example, if boards are left leaning against an outdoor wall. Alert homeowners and commercial building managers to this concern. Educate building owners/operators to eliminate food sources. Carpenter ants do not eat wood; they forage for food and organic debris in and around buildings—this can include food scraps and crumbs left by careless building occupants. Keeping a building clean will dramatically reduce the risk of carpenter ant infestations. Inspect for infestations. Regularly inspect for termite tubes on exposed foundation walls and other evidence of termite infestations. The presence of many winged carpenter ants inside the building is evidence of a colony, while seeing a few foraging ants is more likely evidence of ants from outdoors getting in. Powderpost beetles can sometimes be heard in wood as a ticking sound. Use a bait system for insect control. If evidence of termites is found in a building, employ a bait system, such as Sentricon, for control. The services of a licensed pest control operator are needed for use of most bait systems. Use pesticides only when a colony is located so that application can be highly targeted. To minimize risk to building occupants and the environment, use non-bait insecticides only when the actual insect colony can be located. Use least-toxic pesticides for targeted treatment. Environmentally benign treatments include borates and boric acid, as well as Bio-Blast. Use track-off mats or the “indoor/outdoor” footwear technique. Studies have shown that over two-thirds of the dust in buildings is tracked in on occupants’ footwear; this can provide media for pest growth and can introduce pollutants or toxins.
