Termites in Maryland

The eastern subterranean termite, the most common termite in the eastern U.S., lives in underground colonies located between two and thirty feet below the ground, near large food supplies. Worker termites continuously leave the colony to find food and bring it back to feed the colony. Since termites eat wood, unprotected homes are an attractive food source and may be quickly infested.

Three popular termite treatment systems in use in Maryland and the DC area are the traditional repellent barrier system, the non-repellent barrier system, and the bait system. Each system has its advantages and disadvantages. Ask your trained pest control professional which system is best for your property.

Repellent barrier systems. The traditional repellent barrier system places a chemical barrier between the ground and every potential entry point into the house. A termite repellent is applied to the soil around the foundation of the house and to any breaches in the foundation and slab. Accessing all of the application points usually involves drilling into the foundation. Chlordane, a very effective and long-lasting chemical repellent, was commonly used until the EPA removed it from the market in the 1980s. The barrier chemicals used today are less durable than chlordane and must be reapplied after a few years.

Non-repellent barrier systems. The non-repellent barrier system is similar to a traditional barrier system, except that the active ingredient used is not a repellent. The termites cannot detect and avoid the active ingredient and thus bring it back to the colony, where it can either eliminate or substantially reduce the colony. While it can be applied in the same invasive manner used for repellent barriers, some non-repellent chemicals can also be applied solely to the soil around the outside of the foundation; of course, if termites have already accessed the interior of the house, localized application to those areas must also be done. This generally less-invasive dual approach to termite control is known as the Exterior Perimeter Plus Localized Interior system of treatment (EP/LI). 

Baiting system. The baiting system strategically places a series of wood baits around the house. The intention is for termite colonies to encounter one or more of the baits before approaching the house. Once termite activity in the bait is observed, the bait wood is replaced with an active ingredient. The termites bring the active ingredient back to the colony, and the colony is either eliminated or substantially reduced. This system is relatively new to the market. The success of the baiting system depends, of course, on the termites encountering the bait before finding and damaging the house.

When comparing proposals for termite work from different companies, make sure you get the details in writing and read the fine print. A detailed proposal should be specific in the scope of work. It should outline what chemical will be used, including the amount and concentration. It should also specifically detail the areas and manner in which the chemicals will be applied. If one company proposes to do more comprehensive work than another company, a higher price might be a better value.  

Termite Warranties. Many pest control companies sell either a “Termite Re-treatment” warranty or a “Termite Re-treatment and Repair” warranty. The “Termite Re-treatment” warranty promises repeat treatments if termites come back, but it does not offer compensation for any termite damage that might have occurred. A “Termite Re-treatment and Repair” warranty provides both treatment and compensation for termite damage. The amount of liability the pest control company assumes is usually specified in the agreement and varies from company to company.  

Termite warranties typically require a large first-year treatment fee to cover the cost of inspection and initial treatment and a much smaller annual maintenance fee to cover the ongoing annual inspections and liability. Because many termite control companies do not warrant other companies’ work, switching termite companies usually requires re-treating the house. As the cost of re-treating is substantial, the best time to switch termite companies is at the end of the term for the warranty, not at an annual renewal.