THEY COME UNINVITED, WITH empty arms and without so much as a six-pack of Pabst Blue Ribbon or a stick of jerky, and they can eat you out of house and home. These bands of miscreants aren't your in-laws (though the behavioral patterns may seem familiar), and they're not your poker buddies or your chums from the lodge. The perps in question are household pests.
A pest comes in many forms—a subterranean termite, a powder post beetle, or a carpenter ant. And he does not work alone. He travels with his posse in tow and prefers to work under the cover of darkness or behind the walls. But one thing is clear: The pest and his buddies set up shop and often leave nothing but destruction in their wake.
As a builder, you're probably saying to yourself, “What do I care? Once I'm finished with a subdivision and move on to the next one, it'll be years before the home buyer starts to see the effects of termite damage or dry rot.” While indifference is a tempting tack to take, it is one that is rife with potential problems.
“Some pests, such as powder post beetles, may appear within the first year, and the builder will be directly responsible,” says Dr. Michael K. Rust, professor of entomology at the University of California Riverside in Riverside, Calif. “Subterranean termites may also swarm from existing infestations within the first few years. Drywood termites may swarm into building developments before they are even completed. I have seen sites attacked in frame stage.”
Infestation also could have started long before the lumberyard delivered your studs, so what might look like a good piece of lumber on the surface could actually be a hotbed of activity inside. Never mind the damage, just the appearance of pests can be unsettling to a homeowner. “The mere presence of these insects and the possibility that the developer may be responsible is enough to generate legal problems,” Rust says. And when enough of your buyers have problems and they start to complain, do you really want to be known as the builder who serves up houses with insect insalata?
Just who are these evildoers, you ask, and what can you do about them? We're here to tell you. The following are five of the most problematic pests (in no particular order) and some simple preventive steps you can take to reduce the risks they pose to homeowners. Experts say these five pests are likely to be seen by your buyers if you are not vigilant and that they cause the most financial and aesthetic damage to your homes as well as your reputation if left undetected and untreated.
According to a fact sheet published by the Oregon State University Integrated Plant Protection Center in Corvallis, Ore., “Most rodents have little contact with humans. Nevertheless, some species [such as] rats and mice are pests in houses, agricultural crops, and food storage.” Rodents, the paper continues, can transmit more than 20 pathogens to humans.
The three main rodents your home buyers should worry about are the common rat, the roof rat, and the house mouse. Rodents may kill plant crops or eat and contaminate stored food.
Despite their reputation, rodents are actually extraordinary animals. For example, rats can chew through concrete and metal, survive a fall from a five-story building, develop immunity to poison by taking small bites of it, and learn to count. Mice can squeeze through spaces as small as a nickel, while rats can squeeze through a space as small as a half-dollar by compressing their bodies, which isn't particularly good news for a homeowner.
No, rodents are bad news, and they are trying to find food and warmth inside your house. “Rodents may come in through almost any opening—pet doors, holes in walls, missing vent screens, openings around pipes, dryer duct vents, etc.,” according to a fact sheet by the National Pest Management Association in Dunn Loring, Va. “The roof may also be a handy highway into your home. Rats can climb plants or trees that are too close to the house. That's where roof rats get their name.”
But there is hope. “Make sure cracks and crevices around windows are sealed,” says Michelle Smith, an entomologist and customer technologist at Dow Agro Sciences in Indianapolis. “A lot enter at ground level, so make sure there are no gaps under entry doors and garage doors. Kitchen vents, bath vents, and chimneys should also have screens.”
To Find Them
To Avoid Them
ACCORDING TO A FACT SHEET WRITTEN by Michael F. Potter at the University of Kentucky College of Agriculture, the term “powder post beetle” is used to describe several small wood-boring insects that create narrow tunnels in wood as they feed and reduce the wood to a fine, flourlike powder.
These little buggies are most likely to be found in softwoods, such as pine, spruce, or fir, or in certain hardwoods, such as oak and maple—essentially, the stuff used frequently in your homes. The National Pest Management Association says there are several hundred species of powder post beetles, but fewer than 20 are widespread. Some regions may have a particular type.
Potter writes that the two most common and destructive families in Kentucky, for example, are the Lyctidae, which attacks only hardwoods, so infestations are most often found in wood paneling, molding, window and door frames, plywood, hardwood, and floors; and the Anobiid, which attacks hardwoods and softwoods usually found in such structural members as beams, sills, joists, studs, and subflooring.
Homeowners can tell if they have infestations by the small, round holes in the wood surface where adult beetles have chewed out the wood after completing their development. In general, powder post beetles emerge from wood used in construction from one to 10 years after the house was built. Lyctids, Potter says, rarely infest wood older than five years, which is bad news for you because it means that they are generally found in new homes or newly manufactured products.
“In almost all cases,” Potter writes, “infestation results from wood that contained eggs or larvae at the time it was placed in the home. This is significant because responsibility for damage/replacement often resides with the builder, cabinet maker, or furniture manufacturer rather than the homeowner.”
Your friendly neighborhood powder post beetle usually appears in wood that was improperly dried or stored, so make sure you are buying good lumber and ask lots of questions. Moreover, the critters do not lay eggs in finished or painted wood, so unfinished and unpainted wood, Potter writes, is in question. It also is a good idea to control the moisture in wood products and to be careful when purchasing studs and joists. In short, no wet wood, no improperly dried wood, no exceptions.
To Avoid Them
TECHNICALLY AND SCIENTIFICALLY speaking, mold is not a pest. But those homeowners who have experienced the unsightly black or green spots growing in the basement or the bathroom might beg to differ. Homeowners may even have a few choice terms for it besides “pest.” Nevertheless, mold is a serious problem.
When most people think of mold, they think of Stachybotrys chartarum, also known as Black Mold, which has caused widespread concern in recent years. The hysteria, no doubt, is caused by headlines such as this one by abcnews.com: “Black Mold Panic Has Families Fleeing Their Homes,” or “Killer Mold,” by the New York Daily News.
Whether or not the panic is warranted from a health perspective is up for debate, but the fallout from the implications that one of your homes has mold can be a serious litigation problem, so builders would be well advised to pay careful attention to moisture intrusion in their homes. And Stachybotrys, which poses no structural threat, is not the only concern. There are others.
“Microfungi, in general, are not wood-destroying organisms, with the exception of some soft rot species such as Chaetomium spp that decay the bottoms of posts in the ground,” says Jeff May, of J. May Home Inspections in Cambridge, Mass. “The macrofungi that pose the greatest risk to wood structures are Meruliporia incrassata (also called poria) and Serpula lacrimans (also called dry rot). These turn wood framing, particularly sills, into dust.”
May, author of The Mold Survival Guide and My House Is Killing Me! The Home Guide for Families with Allergies and Asthma, has been a home inspector for more than years and renovated homes before that These days, he spends his time identifying the causes of mold and other moisture problems.
One of the biggest causes of wood decay, May says, is improper window cap flashing. “Every unit needs a flashing that sheds water.” Once moisture infil trates the window, that's where the trou ble begins. “OSB is typically made from poplar or aspen, and they have no natural resistance to mold,” he explains. “If you were to take a piece of poplar and put it in water, it [would] have wood-decaying mold in months.”
To prevent such rot, the structural wood within buildings must always be kept dry, and wood in contact with concrete should be treated. In addition, May says the roof should have enough of an overhang so that water doesn't blow back on the house.
To Avoid It
IN MARCH, THE NATIONAL PEST Management Association put the Northwest on notice: “This winter's near-normal temperatures and precipitation mean a busy spring for carpenter ants,” the association said in a press release. “Colder winters normally put pressure on pests and their survival into spring, but 2004 is promising a pest-filled season.” This is cause for concern.
Carpenter ants are relatively large—for ants, anyway—and red to black in color. As the name suggests, carpenter ants love working with wood, which they hollow out for nesting, leaving behind coarse sawdust. “Carpenter ants nest in both moist and dry wood but prefer wood which is moist,” Potter says in his fact sheet. “Consequently, the nests are more likely to be found in wood dampened by water leaks, such as around sinks, bathtubs, poorly sealed window and door frames, roof leaks, and poorly flashed chimneys.” Nests can also be found in the moist hollow wall spaces behind a dishwasher or in a hollow porch column.
Because carpenter ants may establish colonies in different ways inside or outside the structure (and in a number of different locations), it is sometimes difficult to discover the infestation. The ants inside a home may have actually come from a parent colony or from one or more satellite nests either outside or inside the house. For example, the ants may be coming from the parent nest located outdoors, from one or more satellite nests hidden behind a wall in the kitchen or bathroom, or from wood dampened by a roof leak in the attic.
How much infestation you have depends on how many carpenter ants you have and how long you have had them. Large carpenter ant colonies are capable of causing serious structural damage (though the damage is not normally as serious as that from termites), and preventive measures should be taken.
Make sure roofing, window and door flashing, and siding are installed properly to prevent leaks and other moisture intrusion that attract the ants. Make sure trees and other vegetation are not planted too close to the house; these serve as bridges between the house and the possible carpenter ants nesting outside. Finally, seal cracks and openings in the foundation, especially where utility pipes and wires enter from the outside. Don't make it easy for the interlopers to come in.
To Avoid Them
PERHAPS THE GRANDDADDY OF ALL pests is the termite, especially the subterranean variety. To give you an idea of how destructive this little guy can be, it is said that it causes more damage annually than hurricanes and fires: between $1 billion and $2 billion. “Termites have always been one of the major pests in this country—the Formosan in particular,” says Kevin Powell, research analyst and wood products specialist at the NAHB Research Center in Upper Marlboro, Md.
The Formosan (also known as the Super Termite) inhabits 14 states, including California, Arizona, Texas, Nevada, and Virginia—areas where the most new houses are being built in this country. No doubt, these critters look at your work and see lunch and dinner and breakfast and ... .
The most voracious of all termites, a Formosan colony will eat an amazing 1,000 pounds of wood per year, compared with seven pounds for domestic species. The East Asian bug hollows out beams, walls, floors, and any other wood products you can throw at them. “The rate of the damage depends on the region,” says entomologist Smith. “In warmer climates, it can happen very quickly.”
Ironically, the superstar Formosans are light-shy. They prefer to work behind the scenes (or the walls), so they rarely break through the surface of wood, hollowing it out instead. As a result, you might never see them, or any evidence of them, until you discover that serious damage has been done, says Osmose, a Griffin, Ga.–based company that offers wood preservatives that resist termites, carpenter ants, and fungal rot.
So what do you do? First, make sure you start with good wood, says Dr. Harold Harlan, a senior entomologist at the National Pest Management Association. “Make sure you trust the source of the wood,” he says. “If it's been kiln dried, you can probably trust that whatever has been living in it will be killed.” Smith also says that wood should never come in contact with the soil. And it is a good idea to avoid excess moisture in wood.
“There are baiting systems now that do not involve chemicals,” Smith says, referring to such products as Dow Agro's Sentricon Termite Colony Elimination System. “Chemicals aim to form a barrier to keep termites [away from the house], but they have no impact on the colony. The chemicals also break down in the soil.” Another method uses preconstruction barriers such as Impasse Termite Blocker, which targets common termite entry points—gaps in the foundation along plumbing and electrical penetrations and bath trap areas.
To Avoid Them