[Preventive Pest Management] This Old Pest

"This Old House." "Homes Across America." "Restore America." "If Walls Could Talk." "Before and After." "Hometime." "Curb Appeal." "Bob Vila’s Home Again." "Trading Spaces."

These are just a handful of television shows capitalizing on America’s penchant for home remodeling, landscaping and decorating. The National Association of Home Builders (NAHB) reports that the residential remodeling market earned $153 billion in 2001, which equates to nearly 2 percent of the gross domestic product of the U.S. In addition, the NAHB projects that the remodeling market will increase at a rate of at least 5 percent each year for the next 10 years, and could exceed the market for new homes in that time period.

What do these statistics mean to pest management professionals? "PMPs should educate their customers to call if they are considering renovations," said Dr. Gerald Wegner, technical director and integrated pest management consultant for Varment Guard in Columbus, Ohio. Wegner gave a presentation on this topic at the 2002 NPMA Convention in Orlando, Fla.

"A customer’s service agreement can be voided if any digging takes place near the foundation," Wegner continues. "This action can breach the barrier of termiticide which was applied earlier."

If pest management professionals are included early in the process, they can offer advice and expertise and be alert to any problem areas that may be revealed.

However, a typical scenario unfolds when the homeowner starts renovation, either as a do-it-yourself project, or with a remodeling professional. As walls, floors or siding are removed, pest infestations can be uncovered. "You’ve heard of Murphy’s Law; this is the axiom for the pest control industry, ‘Customers choose those times to make repairs and expose the nests when it’s most difficult for the pest management professionals,’" he says.

Even if a pest management professional gets a call immediately and arrives within an hour, the success rate for dealing with the infestation is minimized. "Carpenter ants can relocate their entire colony within an hour or two, carrying cocoons, eggs and larvae to another part of the house," Wegner says. At this point PCOs are forced to be reactive, not proactive.

PEST ENVIRONMENTS. Environments that promote pest infestations usually contain three elements: a food source, moisture and shelter. For example, say that a couple wants to remove the aluminum siding from a home. Underneath they find the original wood siding, now teeming with carpenter ants.

In another instance, another building product, rigid foam board (RFB), is used as an insulation barrier. However, the product retains moisture, and provides the perfect conduit for termites to travel from the soil into the house and into the woodwork. Homeowners are hesitant to remove the RFB because the contractor’s warranty can be voided.

Finished basements and converted attached garages pose additional problems even after renovation. "The permanent dropped ceiling is very hard to inspect," Wegner said, "and platform floors are a nightmare. If the floor becomes spongy, the pest management professional must drill holes in a checkerboard pattern in order to treat (e.g., using termitcide foam) into all the cells in the suspended flooring, then, depending on product label and state specifications, drill the underlying slab floor and treat beneath it with a termiticide. This usually destroys the flooring, either carpeting or tile, that was laid during the renovation," he said.

Additions, such as family rooms or all-season rooms, present possible pest problems for the roof. These rooms generally have shallow sloping roofs, which can allow moisture to accumulate, especially in the geographical regions of the United States that experience snowfall. This moisture can lead to shingle damage, and if the roof is overshadowed by a tree canopy, moss and algae can thrive — and along with that, silverfish, termites and carpenter ants. Another aspect of these additions can be the inclusion of skylights. Once again, with the accumulation of moisture, leaks can develop around the edges of the skylight.

All of the previous examples dealt with pests finding ingress through building materials on their own. But homeowners and renovators can inadvertently bring pests into the home themselves. "One homeowner wanted to convert a closet into a cedar closet, thinking that the cedar repels bugs, which it normally does," Wegner says. "However, the wood wasn’t cured before it was installed, and the homeowner started seeing small oval holes in the wood, and before long, dozens of iridescent longhorned (cerambycid) beetles were appearing in the closet. Because the wood wasn’t cured, the larvae (round-headed borers) that had been in the wood completed their development and emerged as adults. This type of beetle (Callidium schotti) actually thrives on red cedar. The good news was that once the beetles had been eliminated, there was no concern about a reinfestation."

Another popular decorating practice is using old paneling or beams from barns, but pests can be embedded in such wood. The material should be treated with borates or heat-treated before being installed.

Not all problematic renovations occur inside the home. Landscaping changes can also expose infestations or create possible new problems. "A client can replace old, rotted timbers used in a tiered terrace in their yard with new timbers. The termiticide treatment applied previously would be excavated out, leaving the client with no protection in that area," Wegner says. "It’s important for pest professionals to impress upon their customers that barriers need to be re-established."

The addition of a new deck should come complete with hardware cloth tightly attached as a skirting material around the foundation. This will prevent rodents and nuisance wildlife from establishing harborage under the deck itself.