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olychick2

Powder post beetles in beam?

Olychick
10 years ago

Hi, not sure if this is the correct forum, but thought I'd try for your expertise with wood. I found some little piles of fine sawdust in an exposed Douglas fir beam used to build my home in 1983. The beam has some kind of finish on it, but I have no idea what..oil maybe?

I searched and read about powder post beetles and everything says the wood should be removed/replaced, or the house fumigated - UGH!!! Treatments I see say they can't be used on finished wood. Heat treatment? Could I wrap the beam in something (heat tape, or ?) to create enough heat to kill them? It's a 3.5 x 9" solid beam and my whole house is post and beam construction, so I am really worried about them.

Any suggestions? Thank you!

Comments (9)

  • rwiegand
    10 years ago

    You probably want to bring in a pro, these guys are insidious and can, over a few decades turn your frame into swiss cheese. Borate treatment is about as good and nontoxic as it gets, but I think it has to be done before the wood is finished. If you are in a state that permits fumigation (mine doesn't) you are lucky. My barn was thoroughly infested, treatment of all the exposed wood with Boracare seems to have them at bay for the moment, but this was accessible, unfinished wood.

  • rwiegand
    10 years ago

    You probably want to bring in a pro, these guys are insidious and can, over a few decades turn your frame into swiss cheese. Borate treatment is about as good and nontoxic as it gets, but I think it has to be done before the wood is finished. If you are in a state that permits fumigation (mine doesn't) you are lucky. My barn was thoroughly infested, treatment of all the exposed wood with Boracare seems to have them at bay for the moment, but this was accessible, unfinished wood.

  • Olychick
    Original Author
    10 years ago

    Hmmm...I'm 65. Wonder if I can just take a chance that it won't get completely eaten before I die? :-)

    Thanks for your reply; I won't do anything whole house toxic like fumigation because I am just not interested in poisoning the house then moving back in. But I would put something on the beam if that might work. Any ideas of other options? can you smother them by sealing them in with something?

  • klem1
    10 years ago

    I spect you ran across wood bees while researching this but I thought i would mention them. Powder post damage looks like the wood was shot with bird shot. Wood bee damage is much larger holes about 3/8ths inch.

  • sombreuil_mongrel
    10 years ago

    1) powderpost beetles only enter unfinished wood; they won't bite into paint or varnish, so:
    2) they entered the beam through another piece of framing lumber which was in contact with the beam, or if an unfinished surface was exposed to an open space in a basement, attic, or the crawlspace.
    3) It's likely that they are elsewhere in the house.
    Casey

  • Olychick
    Original Author
    10 years ago

    Casey, this is a beam in the entry area of my home. It has been there since 1983, never been refinished by me, but had some kind of stain/finish on it when the house was constructed. Both ends of the beam are encased in walls, where I am assuming they are each attached to a post, one an interior wall, one an exterior wall. It's about 7 ft off the floor. The little holes and sawdust appeared about halfway across the length, in the middle of the beam, on the top surface. All surrounding areas are sheetrock.

    Could it be anything other than powder post beetles? I have no idea what to do. The holes are tiny with little sawdust piles next to them.

  • sombreuil_mongrel
    10 years ago

    It sounds like powder post, and based on new info, I'm guessing they entered through the attic.
    Casey

  • Olychick
    Original Author
    10 years ago

    okay, thanks. I'll have it all inspected and decide if it can outlive the destruction. :)

  • rwiegand
    10 years ago

    There may be some finishes that completely block PPB from laying eggs, but I've seen wood finished on all sides with shellac, for example, that became infested.

    The holes you see, about 1mm in diameter are the exit holes, the holes in which the eggs are laid are much smaller. Some people recommend using a syringe to inject a borate compound into the exit holes in hopes that it will permeate and kill other beetles present but not hatched or prevent further egg laying in the area. Borate apparently penetrates wood a few cm from where you apply it. "Boracare" is one commercial product for this purpose.