PEST (WOOD DESTROYING ORGANISMS) INSPECTION:
Pacific Crest Inspections, was licensed to perform Wood Destroying Organisms Inspections in Washington State. As of 2013 we are no longer performing WDO inspections but as we see infestations we will refer them to a licensed Pest Control Operator.
Do I need a Pest Inspection? NO – In the Pacific NW most banks are not asking for pest clearance certifications in real estate transaction. All current licensed Home Inspectors will look for pests and report them. By law the inspector must recommend that a pest control operator evaluate and treat the home.
Common Issues in Washington State
The most common issue we find in our inspections is wood rot. Wood rot is caused by a fungus and therefore is considered a WDO.
Dry rot is a misnomer, since the fungus that causes wood rot needs moisture to survive. Generally, once the source of moisture is eliminated the wood rot ceases. Generally, removal and replacement of the damaged wood and elimination of the conducive conditions is the best treatment. Wood destroying pests are primarily termites and beetles, but the category of “pests” also include several other insects of less consequence. Wood destroying organisms are categorized as fungi (often times called “dry rot”), and there are several varieties.
During an examination, a home inspector is likely to discover that insects, plants and animals are in residence. A few of these uninvited guests are capable of destroying the fabric of the building, many of them are unpleasant or unhealthy, and most are unwelcome. If it were not for insects and fungi, our forests and fields would long since have been smothered under their own dead products. Living plants that have defenses against their predators lose them when they die. Some trees such as redwood for siding and cedar for shingles retain their preventive characteristics for years and are therefore much sought after. Most other wood must be artificially protected. Construction lumber, pressure treated with compounds poisonous to fungi and insects, is available for use in critical areas and is now required in some codes for sills and other members that may be close to the ground. Older homes were built without the help of treated wood and continue to be vulnerable. For animals, shelter from the elements and a ready supply of food and water is often irresistible, and may call for stern control measures. Pests and vermin can be discovered anywhere and any time during an inspection. Sellers are often surprised to learn they have been sharing their homes. Timely warning to a buyer of the presence of these unwanted infestations is an important part of a home inspection. Just because you don’t see these pests doesn’t mean they’re not there. Many of these bugs work behind the scenes. They rarely break through the surface of wood, preferring instead to hollow it out. As a result, you might never see them, or any evidence of them, until you discover that serious damage has been done to your home.
Beetles: There are many species of beetle whose larvae destroy wood. In the Northwest the most common is the Anobiid or Powder Post beetle. The females have incredibly thin, flexible ovipositors that can be inserted far below the surface of the wood. The living egg matures into a tiny, active larva with strong, sharp mouthparts. The larva ingests wood, enlarging the cavity as it grows. It digests the starch and excretes the rest of the wood as a fine powder or frass. It leaves the smallest shell covering its hole. After pupating the emerging adult beetle breaks through the surface shell and escapes, looking for a mate with whom to repeat the process.The adults are very small, less than 1/4″ in size. They are flattened and reddish-brown to black in color. Larvae are white, cream colored, shaped with dark brown heads. Larvae create tunnels in the wood and become pupae. As adults they bore out through the wood, pushing a fine powdery dust out. The shape of their holes are round ,about 1/32-1/16 pinholes.
They attack hardwoods depositing their eggs. True Powder post beetles breed in dead and dried hardwoods such as the dead branches and limbs of trees. Their presence is overlooked until they are discovered in stored lumber, rafters, joists, finished wood, and furniture products.
As a rule, they enter lumber while it is being stored and cured, then later, emerge from the finished product. Old items of furniture and wood antiques are especially vulnerable to attack by the beetles. Damage is usually to the starch-rich sapwood of large-pored hardwoods such as ash, hickory, oak, walnut and cherry. The hardwood floors of new homes are commonly attacked
Their diet is starch, sugar and protein in the sapwood of hardwoods however they will also attack common construction lumber. Wood that is less than 6% moisture content is seldom attacked .The life cycle averages one year to complete. This wood-boring beetle is the most widespread in the United States. Many times infestations are built into structures from infested lumber .They can re infest.
Anobiid damage is characterized by: Presence of extremely fine, flour like powder falling from the surface holes. The frass left by other wood borers usually contains pellets, has a course texture and a tendency to stick together. When inspecting damage, be sure to distinguish old damage from active beetle infestations. Recently formed holes and frass(sawdust like) are light in color and clear in appearance….old holes and frass are dark in color. Here is a good article from Washington State University on Anobiid Beetles.
Subterranean Termite The subterranean termite is to be found almost everywhere in the Northern hemisphere because by withdrawing to its underground nest it can survive freezing weather. According to the Washington State Department of Agriculture, termites have rarely been found north of Seattle. Subterranean termite nests with galleries and passageways extending more than 500 feet in all directions are not unusual. Termite workers, looking like small, thick grains of rice, dehydrate easily through their thin skins and so are forced to create for themselves a suitable foraging environment and a protected path of retreat to their nest where they can renew body moisture and deposit the food they collect. With a mixture of saliva, sand and excrement they produce a moisture resistant mortar from which they construct tubes and tunnels, or with which they line the porous remains of wood they have otherwise eaten away. They appear to be drawn to carbohydrates by chemical clues. Any source of cellulose including cardboard, cloth and paper, will be consumed, but termites are picky, and will pass over or around wood that is too hard, too dry, or otherwise not to their taste. Once having discovered suitable provender, they eat the soft parts, leaving the hard layers more or less intact, and filling adjacent previously eaten spaces with a combination of uneaten material and excrement called frass.
Termites in domestic environments are not easily stopped. They can build several inches of tube in 24 hours across the face of a concrete wall and are able to erect freestanding vertical tubes several feet high to reach suitable grazing areas. Their tubes are sometimes found in the spaces between the elements of a sill, between doubled joists or inside built up girders. If their excavations pierce a surface, they repair the hole, often leaving characteristic visible traces along the grain of the wood. Subterranean termites can consume about two feet of 2×4 in a year. This knowledge makes it possible to estimate how long they have been active at a particular site. Informing clients of this fact can help reassure them about the potential for damage involved in an infestation. The inspector can help to calm irrational fears of termites that have, to some extent, been oversold.
Subterranean termites swarm in the spring. Reproductive adults with dark sturdy bodies develop long thin wings on which they are carried by the wind. They are weak flyers and cannot otherwise migrate far from the nest. They shed their wings on landing and dig into the ground. The whole process may take only 15 minutes, but the shed wings remain to memorialize the swarm. If discarded wings are discovered inside a building, there is a colony of active termites somewhere for which treatment is required. Wings found outside may have come from a colony that is digesting the underground remains of a tree and may not yet have discovered the house. Exposed tubes are unmistakable evidence of termite activity. If the surface of the wood has not been affected or if it is covered with plasterboard or paint, termite damage often cannot be found except by probing or drilling. Quiet comers in basements, and damp wood under entry stoops are favorite places for an invasion to start. So are wood support columns whose feet are buried in the concrete basement floor. Termites easily produce unseen tubes in the hollow cores of CMU walls and can pass through a termite shield by using the clearance around an anchor bolt. They may also construct a massive bypass on the outside of the shield that, of course, is easily seen and identified. Indeed the principal advantage of the termite shield is to force the insects to identify themselves by exposing their earthworks. Tubes may extend for surprising distances. Infestations in the attic, or several floors up in an office building have been reported with no signs of activity along the way.
If, when a tube is broken, no termites are discovered, it is not possible to say if the tube is in active use. Inspectors must take the position that the premises are infested if tubes or termite damage are discovered. Documentary proof such as an up-to-date termite policy or a bill for complete treatment of the building within the preceding five years, are helpful, but not conclusive. Caution is necessary .If the documented treatment was performed by a careful exterminator he should have removed all signs of past termite activity as part of his treatment. If this was indeed done, a termite tube discovered during a home inspection will indicate, regardless of documentation, that the premises have become re-infested and clients should be so informed.
Dry Wood Termites. Dry wood termites make their nests above ground. In the warm parts of the country, two compatible adult reproductive termites can fly off and establish a new colony wherever they find suitable conditions. They are not as dependent on moisture as are their subterranean cousins: they take moisture from their food and from the atmosphere. Their colonies may be established anywhere but they are more likely to be discovered in the attic or other high parts of the house. They push from the nest small, football shaped pellets of frass that may be found in the attic, along the baseboards or outside the house. The insects may also be discovered after they have eaten enough for the damaged wood to fail and the failure to be noticed. The entire structure and its contents may have to be fumigated to exterminate them completely, and re-infestation once the fumigant has evaporated is possible.
The Damp Wood Termite. This termite is not often found inside a properly maintained home. It is more likely to be met with in the woodpile or in other places around the property. Damp wood termites do not make tubes. The immediate cure for an interior infestation by this insect is to remove the source of moisture making the wood inedible and the environment inhospitable.
Carpenter Ants. Owners react with varying degrees of horror to black ants, some as large as 5/8” that roam the house in search of food. Carpenter ants do not follow a chemical trail as do sugar or grease ants. Their nests must be discovered by looking for concentrations of activity, or for preferred locations. Small sources of moisture are particularly sought after. Drips from the plumbing, faulty gutters, porous roofing, defective flashings; all are likely to be attractive. The ants enlarge suitable sites by chewing out the wood. Being good housekeepers they remove the chewings from the nesting area. A pile of chips, looking like the debris from a pencil sharpener is a clue to their presence. They may also remove real carpenter’s sawdust from the stud spaces and frass from abandoned termite galleries. A discarded body casing mixed with sawdust (they molt as they grow) is a sign of an established colony nearby. Inside the house carpenter ants feed on sweet kitchen wastes such as honey and jam, and on most kinds of meat, fat and grease. They do not eat wood cellulose. Carpenter ants can be more damaging to a structure than termites because they are capable of removing large amounts of wood in a short time, some of which may be structurally important. However, they do not always excavate. Massive colonies have been found in the soffits of porch roofs, in stud walls, and even in hollow core doors. Although no excavation was needed, a moisture source was always nearby. Carpenter ants and termites do not coexist in the same location, but they may inhabit the same building, nor does rot take hold where either of them are active. Rot often follows after they have vacated the premises. Carpenter ant colonies may be destroyed by poison, but may reestablish a nest in the same location if conditions remain favorable. There is usually a “mother colony” in a tree, stump, log, or other piece of solid wood that could be several hundred feet from the house. They establish a “satellite colony” in the house, and begin chomping away on the structural members of your house. A satellite colony is a place where brood (larvae) are brought for incubation. Unlike termites, carpenter ants don’t eat the wood, they only chew it away to create the tunnels or “galleries” in which they live. They work slowly, but given enough time, carpenter ants can do extensive structural damage.
Most of the time, carpenter ant infestations are treated by a pest control operator, using the “drill and inject” method. Given enough time, carpenter ants can do a lot of damage to a structure. However, the damage is usually isolated. When I find carpenter ants, I look for evidence of structural damage that may need repair if possible, though often this is not possible. In this case, it is necessary to leave investigation for structural damage until after the ants have been eliminated. House Borers A few beetle holes do not severely damage structural members, but over time, enough wood can be destroyed to impair structural strength. Beetle larvae need moisture; therefore if the ambient humidity is decreased, the larvae may be kept from developing. Screening can keep adult beetles out of the house. Females who do gain entry may be discouraged from laying eggs if wood surfaces are sealed with something like paint, varnish, shellac, or linseed oil. Surface applications of poison do not work because laying females do not eat wood, and developing larvae will have made their holes before they reach the poison.
Moisture Ants: Moisture ants will invade homes from nests in the yard while foraging for food. Occasionally, an outdoor colony will relocate inside in the bathroom or kitchen where a water leak is present. This ant often carries soil into the building which it uses to construct a “carton” nest. Carton nests resemble hard clods of soil and may be fashioned around a water pipe or onto a wooden sill plate or wall stud.
Honey Bees. People who know honeybees know they are a blessing, not a pest. Of all the insects to be found around houses, the honeybee is the most maligned. “I’ve just been bitten by a bee!” is the cry, but it is more likely the person was stung by a yellow jacket. Home inspectors may find honeybees in eaves or attics where they have taken advantage of an optimally oriented hollow. Non-aggressive, honeybees are interested only in nectar gathering. If their nest opening and their flight path is above head height, they may not e\’en be noticed by the occupants. Older well-established colonies may have stored large quantities of honey and may therefore leave a real mess if they are casually exterminated. Call in a beekeeper, but expect the process to take several weeks if everything is to be removed.
Roaches. German roaches, the little brown bugs that nest in the kitchen, are often carried into a house in cartons from the supermarket. They hide during the day, but come out to feed at night, and can contaminate any food to which they have access. Highly resistant to many insecticides, they are now reportedly controlled by spreading technical grade Boric Acid that, when ingested, interferes with their metabolism. They also appear to be controlled, for now, with newly developed chemicals to which they have not yet become adapted. Cleanliness in the kitchen is an important factor in their control.
Water Bugs, Palmetto Bugs, Cockroaches. These large insects, as much as 2″ long, prefer the dark and the damp. They will eat almost anything. Treat them like their smaller cousins, the German roaches.
Spiders – The Pacific Northwest has its share of spiders and some can bite. Some are yard and garden species, while others are “house” species. Most of the time they are more of a nuisance to the homeowner but before you start killing remember that they are part of the ecosystem. Here are two good sites to help you identify them
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Terminex Pest Library