Bellingham Home Inspector (King of the House): Analysis Of An Invasion -- Carpenter Ants

A pest that we see often in the wooded Pacific Northwest is the carpenter ant. Carpenter ants are not all exactly the same size or color.  In fact there are many different species but they get their name, as a group, because of the way the ants categorized as carpenter ants chew the wood and build galleries. I have said it before but, to say it again, carpenter ants are not eating the wood, they are building in it. They spit it out again as "frass" which is like fine sawdust. They will work in sound wood but, much more often than not, they get started in moist, decayed wood. I went through my photos of a classic carpenter ant infestation and have posted some pictures that, step by step, depict the causes and symptoms of the infestation. If you realize that they like moist, decaying wood, it is obvious why they moved into this house. These photos at the exterior and in the crawl space are what, in Washington State, we refer to as conducive conditions.

To set the mood, before we go on the virtual inspection, I want to share with you a tune that will get you in the mood. This is a trick that super Seattle inspector Charles Buell uses to stay high energy as he descends into that abyss that is sometimes dark and foreboding and known as the crawl space. He puts this classic ant-themed rhythm and blues number on the walkman, turns it up full-blast and look out wood destroying organisms, your days are numbered. We start at the exterior and then go down below. The short captions under the photos explain the various conducive conditions and problems. I hope this virtual WDO (wood destroying organism) inspection is informative for you.

Blocked vents: no air circulates                  Water dumps against the foundation

Crawl Space: No vapor barrier, moist          Standing water in crawl space from downspouts

Wood to earth contact, rot                        30% moisture in joist, rot possible at 20%

Chewing damage, the fine sawdust is classic carpenter ant frass

Caught in the act. Live carpenter ants inside the joist.

Thanks for checking out my ant farm. For other blogs I have written on this insect, please click here.

Steven L. Smith

Bellingham Home Inspector

www.kingofthehouse.com