CHEMICAL CONTROL OF TERMITES; [ Control Page ] [ Termite Main Page ]

Conventional termite control relies on establishing a continuous chemical barrier in the soil around both sides of your foundation. For houses with crawlspaces, treatment includes applications to the soil around piers supporting your floor system. This barrier should prevent foraging termites from reaching the foundation and piers and, ultimately, the wood in your house. Current state regulations require drilling and treating of the following:
  1. Slabs that adjoin the house (e.g., the garage floor)
  2. The voids in foundation walls, piers, etc. within 4 feet of known termite activity.;
  3. The walls of earth-filled porches within 3-feet of the foundation wall and any structural wood.;
A list of currently approved termiticides and the state regulations governing treatment of new or existing homes is available from the NC Dept. of Agriculture and Consumer Services - Structural Pest Control Division
Trench Treatment
As you might expect, this required drilling will add to the cost of the treatment.;

Although there are liquid termiticides available for homeowner use, we do not recommend the "Do-it-Yourself" approach for chemical control of termites for several reasons:

  1. Effective termite treatments require a significant volume of termiticide. For example, a single-story house that is 1200 sq. ft. (40' x 30') would require 112 gallons of diluted termiticide just to treat the soil along the foundation walls (inside and out). The total gallonage needed may exceed 150 gallons depending upon the construction of the house. Few homeowners have the equipment to deliver this quantity of chemical efficiently and safely.
  2. Drilling and treating slabs, foundation masonry voids and piers takes specialized equipment and training in order to avoid personal injury or damage to subsurface water or utility lines or to the mansonry itself.
  3. The cost of the chemical is higher for over-the-counter products. Let's use the example of chlorpyrifos (Dursban*), a commonly-used termiticide. By some estimates (Lyon, Ohio State University), a Do-It-Yourself treatment done according to label directions using Dursban Ortho-Klor (12.6% chlorpyrifos) would cost the homeowner about 2-1/2 times more money in chemical costs than a licensed pest control operator using Dursban TC (42.8 % chlorpyrifos).

  4. *Dursban is a registered trademark of Dow AgroSciences LLC.

Some companies offer "spot treatments", i.e., they treat only those areas of the house where termites are seen. Spot treatments, except when done under an existing contract, usually carry a limited guarantee (or no guarantee at all). With new/proposed contracts, any treatment procedures that are not done according to state specifications must be noted on an official waiver form, which you must sign as part of your contract. Before you sign a service agreement or contract, make sure that you ask about and that you understand:
  1. The type of service and guarantee that you are purchasing.
  2. The impact of any waiver on the guarantee you are getting.

Problem situations:

There are situations where a conventional termite treatment is undesirable, difficult or impossible. For example:

  1. There is a well under the house or enclosed in a structure attached to the house.
  2. The house has foundation ("French") drains immediately adjacent to the interior or exterior sides of the foundation.
  3. The house is built on a slab or has basement that must be drilled and treated. In some cases, you may not want drilling done indoors (or outside). [Note: some older slab homes have HVAC ductwork embedded in the slab and a conventional termite treatment is not recommended because of the potential for contaminating the ducts.
  4. You do not want liquid termiticides used under or around your home.
In these situations, there are few alternatives such as termite baits or mechanical control.