What Do The Experts Say?

Stop Termite Damage Before it Starts

Dr. Bob Davis B.C.E., BASF Market Development Specialist

In the US, termites strike five times as many homes as fire, and do more economic damage annually than all tornados, hurricanes, and windstorms, combined¹. Because home insurers do not cover termite damage, homeowners spend an estimated $5 billion each year, out of their pockets, to repair these problems. When left untreated, termites have the longest life span of any household pest, with individuals living up to 15 years under favorable conditions, and entire colonies living in homes for even longer. In this time, they may feed on the wood of home structures until little is left but non-supportive remnants, leaving a house that may be physically weakened and exorbitantly costly to repair.

Among the nearly 2,800 species, the most common termite found in the US is the subterranean variety – named for its building of underground nests. This species can be extremely destructive because it tunnels its way through wood (such as the wooden frames of homes) to obtain food. While these insects can be found in every state except Alaska, they are a universal threat in warmer, more humid regions, including the Southeast and lower West Coast of the United States.

It is because of this costly damage that high-risk areas often apply a preventative termite treatment when building a new home. The practice of pre-construction termite treatment serves as a preventative action, offering homeowners long-term protection from costly termite damage and subsequent harm to the builder's business.

In some states and municipalities where termite infestations are common, (such as North Carolina and Louisiana) government regulators have put termite pre-treatment requirements in place for new home construction. Even when pre-construction treatment is not required it is a good idea to talk with your building and check the USDA termite probability map to determine whether pre-construction treatments should be used for your new home.

What is a Pre-Construction Treatment?
Pre-construction termite treatments are made during all phases of construction including the installation of final grade. There are several products that can be used to prevent termite damage, but different products have differing levels of effectiveness and installation procedures.

Due to a number of factors, there is no one technique of pre-construction termite treatment that is feasible for every new home. The way a home will be configured, including the location of its ventilation ducts, inclusion of wells or other private water sources, and the locations of drains will determine the appropriateness of the treatment methods described below.

Liquid Treatments
Treating of the soil with a liquid treatment prevents termites from accessing a home through cement slabs. While a cement slab may seem impenetrable, over time it can crack or shrink away from the home's foundation wall, providing termites access to the wood above it. Termites can also enter your home through bath traps, plumbing outlets, utility or ductwork, and construction joints. Liquid treatments generally fall into two categories: repellent barriers and undetectable liquids.

Repellent Barriers
When using a liquid barrier treatment 100 gallons or more (depending on the size of the home) of a liquid termite treatment is applied to the soil to form a continuous chemical barrier around both sides of the home's foundation. For houses with crawlspaces, the soil is also treated around the piers that will support the floor system. This barrier should prevent termites from reaching the foundation and piers and, ultimately, the wood in the home. For slab construction (including foundations, patios and garages), the entire soil or gravel surface is treated before the vapor barrier is installed and the slab poured over it.

The liquid barrier application is done in stages coordinated with all building activities from foundation construction through final grading of the soil around the building's exterior. In order for the treatment to be effective, the final phase of the application must be done after final grading and sometimes after landscaping is completed, to ensure that the treated soil is not disturbed.

Liquid barrier treatments can prove problematic because any displaced soil or small breaks in the chemical barrier can allow termites through the barrier and into the structure.

Undetectable Liquids
Rather than just repelling termites, undetectable liquids allow termites to freely forage in the treated zone where they come in contact with the termiticide. Those termites then spread the termiticide to others in the colony away from the treated area, helping knock down the population.

Undetectable liquids such as Termidor® termiticide/insecticide require only one application to the soil around the home after final grading², alleviating construction schedule conflicts. Additionally, this product is also highly cost-effective, because its active ingredient can be used in lower concentrations, requiring significantly less product to be used than other formulas³.

Termite Baits
Some homes may not be suited for a liquid treatment. Conditions that make an alternative such as baits necessary include: a foundation drain around the home; ventilation ducts in our under a slab floor; requires drilling through finished walls or flooring, and/or when the home has a well or cistern.

Bait systems rely on recruitment — the assumption that worker termites will discover the wood source, lead others to station, and eventually die by ingesting treated cellulose found in the station. Baits do not create a treated zone around the structure the way liquids do, and some systems require a waiting period after installation because the treated food source cannot be added to the station until termite activity has been detected at that location.

In new construction, baiting systems are not installed until after final grading and landscaping are completed, to prevent the damage or covering of bait stations.

Other Treatment Options
Some conditions that make an alternative treatment necessary include: a foundation drain around the home; ventilation ducts in our under a slab floor; drilling through finished walls or flooring; or when the home has a well or cistern.

Wood Treatment
An alternative to termiticides applied to the soil is the direct treatment of critical structural wood during a home's construction, before siding and sheetrock are applied. However, there is a possibility that termites could eventually enter a slab home through an expansion joint and attack nearby untreated wood, such as baseboard molding. Also, treating the wood does stop termites from building mud tubes, which are mud based tunnels that termites form to help protect them as they travel from the soil to the foundation wall. Some regulatory agencies and inspectors consider the presence of mud tubes evidence of termite activity, whether the insects are found in nearby wood or not⁴.

Physical Barriers
Physical termite barriers are made of a construction-grade, termite-proof sheet consisting of a termiticide "locked in" between outer polymer layers. These barriers are installed prior to and/or during the pouring of the structure's concrete slab. Both of these methods target the areas around plumbing, electrical pipes, and conduits, which could present an entry point for termites.

Case Study: Habitat For Humanity Site

In keeping with its legacy of providing safe, affordable housing for low-income American families, Habitat for Humanity started work in fall of 2007 on building a development of 55 single-family homes in Evansville, Indiana, mostly for displaced hurricane Katrina families, as part of its Operation Home program.

Based on the USDA termite probability map Evansville was not a high termite pressure region, but the land chosen for the Operation Home program faced other factors that contributed to the high termite risk. The land was previously a wooded wetland and contained two of termites' favorite things–moisture and wood. Jim Werner of Collins Pest Management brought the termite pressure issue to the attention of the Habitat for Humanity board. He had worked with Habitat for many times before as a volunteer, and once he learned about the land chosen for the Operation Home program he suggested that homes receive preventative treatments.

The Evansville Habitat for Humanity board was excited to have the homes protected against possible termite damage, but the board was also concerned about scheduling conflicts and construction delays due to the treatments. Werner alleviated their concerns when he described his chosen treatment method. He recommended using Termidor® Perimeter Plus™ to treat the homes after final grade, keeping from interrupting the construction schedule, and allowing the families to move into their homes with peace of mind.

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• Eliminate conditions in and around your home that attract termites