What is a WDO Inspection?

We want to keep our homes in the best shape we can. That’s why we schedule inspections of all sorts. This is especially important with a WDO inspection

If you see even the slightest sign that there might be a wood-destroying insect in your midst, you want to get the problem taken care of as quickly as possible. After all, termites alone do billions of dollars in damage to homes and other structures every year. Bugs and other organisms that can damage wooden structures are an issue you’ll want to nip in the bud before it becomes a real problem.

What is a WDO Inspection?

A single colony of wood-destroying insects can do irreparable damage rather quickly. If you come across the wood in or around your home that appears damaged, and you’re not sure what caused it, you must contact a WDO inspection service right away. Colonies of wood-damaging pests often expand or break off to form new insect communities. If you find damage to a fence post across your yard, that damage can spread to your home if it’s left unchecked.

Insects aren’t the only type of pest that can cause problems for wooden structures. So, if you suspect anything out of the ordinary — signs of wood rot, unexplained holes, or weakened wood — contact a WDO specialist.

Specialized contractors, called WDO inspectors, typically do one of two types of inspections — a complete WDO inspection or a limited WDO inspection. Both types involve looking for signs of organisms that cause wood damage. The inspector will make certain recommendations based on what they find in each case.

A complete WDO inspection involves going through a structure, around the property, and thoroughly examining all accessible areas. The inspector looks at all visible wood surfaces, between rafters and joists, and they can point a flashlight into every hidden cavity. They’re looking for signs of wood damage that wood-destroying critters can cause. 

Inspectors look for several signs of wood damage from organisms and also keep an eye out for conditions in which wood-damaging organisms thrive. 

Inspectors look for the following indications:

  • Any sign of termite activity, such as shelter tubes, insect waste, or damaged wood. 
  • Conditions ideal for wood-destroying creatures
  • Nearby dead tree stumps 
  • Wood that touches the ground.

During the interior examinations, WDO inspectors typically look at the following for signs of infestation:

  • Visible woodwork, wood floors, banisters, and wood molding.
  • Overhead joists in basements
  • Uncovered wall studs
  • Crawl spaces
  • Attic rafters
  • Exterior wood siding

A contractor will come out for a limited inspection if you believe you’ve seen signs of wood-damaging pests. They inspect the area of concern. If the inspector finds signs of an infestation, they’ll usually highly recommend doing a full inspection right then and there or scheduling a complete inspection very soon.

If you have any concerns about your inspector’s qualifications, ask about their NACHI-issued WDO certification.

What is a WDO Report?

After a WDO inspector has completed their examination of the property, they’ll discuss any issues they’ve come across. They also record what they find in a WDO report. The report will include helpful information, including the following:

  • The status and location of infestation — if any — on your property.
  • Conditions that may promote a WDO infestation
  • Your risk level for developing a WDO infestation
  • Recommendations for treatment and prevention of a WDO infestation.

Very few states require a WDO report before selling or purchasing a home. Even for those that don’t, most financial institutions require a WDO report as a condition for giving out home loans. The following states and districts require a WDO report as part of getting a VA loan for a home purchase:

  • Alabama
  • Arkansas
  • Arizona
  • California
  • Connecticut
  • Delaware
  • Florida
  • Georgia
  • Hawaii
  • Iowa
  • Illinois
  • Indiana
  • Kansas
  • Kentucky
  • Louisiana
  • Massachusetts
  • Maryland
  • Mississippi
  • Missouri
  • North Carolina
  • Nebraska
  • New Jersey
  • New Mexico
  • Nevada
  • Ohio
  • Oklahoma
  • Pennsylvania
  • Rhode Island
  • South Carolina
  • Tennessee
  • Texas
  • Utah
  • Virginia
  • West Virginia
  • Washington, D.C.

What is a WDO?

WDO stands for a wood-destroying organism. We typically tend to think of termites and carpenter ants when we talk about WDOs; there are far more than just these pesky insects to consider. 


Several fungi cause wood rot. You find these mostly in untreated wood, holding onto moisture for an extended period of time. Some fungi weaken the wood by forming cracks and weak points as it eats through. Others consume the wood from the inside, making it spongy and insecure.


  • Termites – Termites are the single greatest threat to our wooden structures. In the U.S., over 600,000 cases of termite damage happen annually. Worker termites are the most common. They’re easy to spot by their creamy-white color and often have wood dust and soil stuck to their bodies. Termites capable of reproducing have wings and look a lot like winged ants. In the spring and fall, flying termites will swarm from their nests in search of a new place to build their colony. 
  • Carpenter ants – Carpenter ants vary in size and color but are identifiable by their clean, glossy surface. Carpenter ants build their colonies inside the wood — rarely eating through and providing visible signs of their presence. Though not as famous for damaging homes as termites, carpenter ants can become a major problem once they’ve set up shop in your walls.
  • Powderpost beetles – Powderpost beetle problems are the worst on the eastern and western coastlines. Though not as prevalent as termites and carpenter ants, these insects can cause some severe damage if they get into the wood of your home. 

Signs of Wood-Destroying Insects

Different WDOs produce different signs of infestation, but here are some signs of wood-destroying insects you can look for to decide if it’s time to call a WDO inspection service.

  • Small holes are a common sign that something’s been eating through your wood, primarily if the holes are clustered close together.
  • Small, unexplained piles of sawdust point to several possible wood-eating insects.
  • When wood that once hard becomes spongy or springy, this can signify a wood-damaging fungus.
  • Sounds inside your walls like crinkling cellophane could indicate scurrying carpenter ants or termites.
  • Prod suspected infestation sites with a screwdriver. Many narrow channels in the wood strongly suggest a wood-destroying insect, like termites or carpenter ants.
  • Worker termites and ants will often spill out of new openings in the wood, such as when you prod the wood with a screwdriver.

Damage Caused by WDOs

Most WDOs do similar types of damage, though the external appearance of that damage may differ. The worst of it comes from them eating away at the inside of the wood where you can’t see what’s happening. By burrowing into the wood, insects eat away at the structural integrity of the material one bite at a time. Eventually, there isn’t enough material within the wood to support what’s left, and it collapses in on itself. 

If WDOs do enough of this kind of damage to support beams, ceiling rafters, or floor joists, whole structures can collapse. Though there are no statistics on injuries related to termite damage available, people spend over $1 billion every year in the United States to repair WDO damage.

The Bottom Line

Wood-destroying insects and fungi cause significant problems in homes nationwide if you don’t take care of the problem right away. If you run across any signs whatsoever of insects causing damage to the wood in your home, contact a WDO inspector as soon as possible.  Once they’ve completed their inspection and written up their report, follow the inspector’s recommendations. You may have to fork out a few dollars to get rid of the problem. The money you spend getting ahead of the issue will save you money, time, and frustration down the road.