Wood Beetles In Old Homes
Anobiid wood beetle infestations are a very common and sometimes significant problem in older homes. Much of the lumber was milled without kiln drying which would kill any of the insects that were already in or on the wood. So despite the use of old growth lumber these insects, over time, can turn that very dense, hard and strong material into something that resembles balsa wood. Joists, beams, posts, subfloors can easily lose their ability to support the house. And the crawlspace provides an ideal environment to allow these critters to thrive.
The insects continue to reinfest the structure and often live in the wood for 5-7 years or more. If your home was built in the early 1900’s then you can have close to 20 generations of wood beetle activity.
Any house that is over 60 years old with a crawlspace should be evaluated for the signs of wood beetle activity which include tiny holes which look like dart holes and sometimes, like in the photo, sawdust is visible. And yes you WILL have to wander a bit because they aren’t always conveniently located near the hatch. Whether you are buying or selling an older home this issue is one to keep an eye out for.
Should signs of the insects be found contact a licensed Structural Pest Inspector for further evaluation (John Wagner of House to Home Inspections is a licensed Structural Pest Inspector). A licensed contractor should then be contacted to assess and repair any framing which has been compromised due to the insect damage. Then chemical treatment of the framing should occur to protect it from continued and future infestations.
The treatment is very simple. A Pest Control Operator can treat the framing, typically with a borate based solution which stays on the wood indefinitely, as long as it stays dry, and is relatively harmless to people and pets once dry. As the beetles emerge from the wood they ingest the chemical and can no longer reproduce and the infestation is eventually eliminated.