Management Control measures include reducing the potential for subterranean termite infestation, preventing termite entry, and applying residual chemicals for remedial treatment.
Thorough inspections can determine whether infestations and damage are present, whether remedial control measures are needed, and what conditions can encourage termite attack. Inspections can be performed by anyone who knows the basic construction elements, the environmental requirements for termite survival and the behavior of subterranean termites.
Tools and equipment needed for an inspection include a flashlight, ice pick or sharp-pointed screwdriver, ladder and protective clothing (bump cap, coverall, rubber knee pads). A clipboard, graph paper and floor plan or sketch help in recording inspection findings accurately and ensuring that the entire structure has been examined. A moisture meter can often detect increased moisture levels in the shelter tubes hidden behind walls, as well as high moisture conditions that encourage subterranean termite infestations.
Where to check outside Examine the foundation of the house, garage and other structures for shelter tubes coming from the soil. Pay particular attention to attached porches, connecting patios, sidewalks, areas near kitchens or bathrooms and narrowly confined or hard-to-see places. Check the soil moisture around or under the foundation to determine if faulty grade construction creates moist areas next to the structure. Check window and door frames and where utilities (air conditioning pipes, gas and electric services) enter the structure for termite infestation or wood decay. Observe roof eaves and guttering closely for defects that might cause leakage and eventual wood rot. Inspect behind closely planted, dense shrubbery or foliage. Note particularly any earth-to-wood contact such as fences, stair carriages or trellises. Open and examine any exterior electrical meter or fuse boxes set into the walls, a common point for infestation. Carefully inspect wood materials next to swimming pools that may be splashed frequently by water.
Where to check inside Probe or carefully sound exterior porches, doors and window facings, baseboards, and hardwood flooring. Be careful not to deface finished wood when probing. Carefully examine any attached earth-filled porches. Examine all known or suspected joints, cracks or expansion joints in the foundation and unusual blistering in paint or wallboard surfaces. Discoloration or staining on walls or ceilings may indicate water leaks that can decay wood and aid termite infestation. Especially inspect where plumbing or utility pipes enter the foundation or flooring. Check the floor covering for raised or split areas. Carefully examine the plumbing, particularly in bathrooms on slab construction. There should be access to the bath trap area. If none exists, build a removable plumbing hatch for periodic inspection. Examine the attic for shelter tubes, water leakage, wood rot or damaged wood. If the house is of pier and beam construction, thoroughly inspect the area between the floor and the underlying soil (crawl space) (Fig. 5). Examine the inside of the beams, chimney bases, hearths or piers for shelter tubes. Crawl-space construction should have a minimum of 18-inch clearance between floor joists and the underlying soil, and a least 12 inches between floor beams and the soil. Examine areas underneath or close to earth-filled porches, patios, planters and bathrooms for water leakage and termite damage. Remedial action may be required to control moisture if water stands under-neath the house. Look carefully at the top of the foundation wall where the floor and the wall intersect. Closely examine plumbing and utility lines passing through the floor of foundation walls.
A plastic film used to cover at least 70 percent of the area underneath the house may prevent moisture build-up in the subflooring. Place foundation wall vents opposite each other and close enough to the corners of the foundation to provide cross flow ventilation and eliminate dead air spaces. A rule of thumb for the number and size of vent openings is 1/150 of the net area covered by the building. Wood exposed to constant wetting from rain should be pressure-treated. Wood marked “Wolmanized “ is worth the added cost. Rest wood porches, steps and stair carriages on concrete bases and separate them from the soil by at least 6 inches. Seal foundation openings, such as for plumbing wraps and service utilities, with a good grade of roofing coal tar pitch or rubberoid bituminous sealer. Remove extraneous cellulose material, such as wood scraps or stumps, from underneath and around foundations.
Subterranean termite attacks on houses and other above-ground wooden structures emanate from the soil. Chemicals applied to the soil can deter attacks for many years. To prevent termite entry, develop a barrier of chemically treated soil between the structure and deeper soil areas.
Chemical soil treatment before construction can be as effective as treating existing structures and is considerably less expensive. Chemicals applied during certain phases of construction eliminate the necessity of drilling injection holes, allow more accurate application and do not disrupt the household. Unfortunately, many municipalities do not require pretreatment in building codes or do not enforce compliance. When building a home, insist that the contractor or architect specify pretreatment. Check city building code requirements also.
Termiticides should be applied to the soil inside and outside foundation walls, around piers or other supports and around utility entrances (Fig. 7, 8, 9). In some instances, such as in foundations of concrete blocks or bricks, the insecticide must be pressure-injected through drill holes into foundation walls. For slab foundations, extensive drilling and pressure injection often are necessary in the foundation as well as under earth-filled porches, around fire places and along adjacent patios and sidewalks.
These treatment strategies are for subterranean termites. Drywood termites are treated differently, usually by removing infested wood, using spot treatments where the colony is located, or, if needed, by tarping the structure and fumigating.
Termite treatment requires specialized equipment such as drills, pressure injectors, pressure-generating pumps and high-gallon tanks. Therefore, in almost every instance, using the services of professional pest control operators is recommended. They are familiar with construction principles and practices, have the necessary equipment, and know termite biology and habits. Members of the pest control industry who offer termite control should be licensed or certified by a state agency for competence in treatment procedures that provide safe and effective control.