[Greenbuilding] Oak

[Sacie Lambertson]

When we built our house we used oak, honey locust and walnut timbers from
our land, trees cut down by my husband and milled on site.  There was
evidence of powder post, or p.p-like critters in some of the oaks and more
so in the honey locust. Since we had a finite number of beams to use for the
project, I did eliminate all the oaks that appeared to have any beetles, but
needed to retain the rest, I extensively researched what I could do about
it.

I found out that there is no way to really get rid of them except to to
officially exterminate them through a tenting procedure.  I could not buy
the necessary poison in this State and the  professionals required I
transport them to a trailer where they could take care of them, an easy
solution had there not been 56 timbers many 16 feet long and darned heavy.

Borate is not effective I was told and read in any number of articles, nor
are any of the commercial products on the market.  The beetles have a cycle
where they escape from the wood at some point (thus the small holes you
see--the size of which and the frass, is what determines powder post or
other) and then there is a return to the hole at some stage of the critter's
development.  If one covers the hole so no return is possible it was my
understanding the infestation could be limited.  So I painted my timbers
with several coats of clear acrylic. And hope.

If you don't see the holes I believe there should be no beetles in the wood.

I've seen the destruction of these beetles in 1-2 inch boards; it doesn't
take a long time, only some years for them to carve out sufficient interior
wood to ruin a piece, so I would be careful with this.

For more info on the beetles check out University publications/studies.

Sacie L.