Saving beetle-damaged reclaimed framing lumber
severaltypesofnerd
| Posted in General Questions on
Is there a practical way to make safe beetle damaged framing lumber?
In this case it’s 1930’s era old growth douglas fir 2×4 rafters, which were removed then stored outdoors. Pretty much all of them have beetle exit (or entry) holes (see representative picture). The wood is plenty strong, but clearly the beetles can (and did) spread.
In theory killing methods include: heat/kiln cooking, chemical saturation, microwave energy like that used for termites, freezing. But in practice, in the San Francisco Bay Area, is this wood compost or fixable? What’s the green thing to do?
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Replies
Bryce,
I have some wood like that in my home -- an exposed spruce floor joist above my living room, and a maple bench in my mudroom. Both were trees that I cut down. In both cases, the insects chewed noisily and eventually left. The wood has been fine for 40 years -- the insects did not return. Of course there are still visible holes.
I know that beetles exit, mate, and often reenter the same piece of wood. In the stored framing above it's pretty clear they hopped from piece to piece. The wood is too risky to use.
I have some interior wooden kid's blocks that had a beetle problem. In 5 years they jumped between various unfinished blocks but never touched the varnished ones from the store. After 5 years indoors, I split the blocks and found live beetle grubs and extensive tunneling.
So the beetles can live indoors for a long time. Slower than termites, but relentless. The framing lumber, unlike the kid's blocks, is too big for the microwave oven.
Martin, unfortunately that's not really an answer. I'm not willing to invite beetles into an existing beetle free house. Is there any way to salvage this lumber?
Bryce,
If you want them gone quickly you can kiln dry the lumber, but that will be expensive. Treating it with Bor-A Care will also work, but may take months before the entire beetle lifecycle is interrupted.
Compared to kiln drying lumber, which takes a long time to get all the moisture out, kiln baking to kill bugs can take much less time, and so costs less and uses less energy.
Bryce,
I agree completely that I did not provide an answer. I shared an anecdote. Good luck.