Heating Old Wood to Kill Bugs

Thirty minutes at 130 degrees F should do it. September 27, 2008

I am having some 100 year old white oak resawn for interior paneling. I want to debug this material. I've read that you can do this with temperature, getting your materials up to 160 degrees for at least 24 hours. Well stickered and vented. Can I use some sort of bug bomb to do the same thing? Create an airtight compartment around the wood and debug it with chemicals? Dip materials in solution?

Forum Responses
(Sawing and Drying Forum)
From contributor J:
What species of insects are you seeing? Right off the bat I can say that insecticide is probably a bad idea if any humans are going to come into contact with the wood in the future.

From contributor M:
Since it's white oak, you could make your piece(s), then ebonize with ammonia vapors using your chamber arrangement. Charge extra for the craftsman finishing technique and debug as a byproduct. Just a thought.

From the original questioner:
My main concern is that I am not bringing any insect into the home. I cannot be sure if the wood is infested or inhabited. Heat is the easiest answer. I see that 130 degrees for 24 hours will kill insects... Is that all insects? These hand hewn beams were outside before being resawn, and since then they have been under cover, unheated. Cut about a month, I will be picking them up this week and will check MC. I need to sterilize the wood, if that term is applicable here, to assure it is clean.

From contributor R:
Heat it.

From contributor P:
I've spoken to commercial pest control companies and there is one in our area that is certified to chemically fumigate wood. They use a sealed chamber and safety precautions. You might want to call around to these professionals to see if you can find one that is certified to fumigate wood in your area.

From Professor Gene Wengert, Sawing and Drying Forum technical advisor:
I would question whether you can fumigate white oak without using special procedures that would be very expensive. The property that keeps water (wine or whiskey) in a white oak barrel will also keep the fumigation gas out. Therefore, use heat. You only need to get the wood up to 130 throughout for 30 minutes to do the trick. The 160 F quote you have is likely for softwoods for setting the pitch.

From contributor W:
There are pallet companies that sell sterile pallets. They cost more and I'd guess it's probably for foodstuff. See if you can find a pallet mill near you to do your job. Also, you might consider denatured alcohol. I like to make stuff out of buggy walnut and I soak everything in the alcohol for 24 hours. That seems to get the nasty critters. It doesn't raise the grain and dries out quite quickly. You'd probably have to make a long shallow box and line it with plastic, then pour in a few million gallons and you're golden.

From Professor Gene Wengert:
I believe that sterile pallets refer to heat treatment, making the pallets acceptable for export without any insects in them.

From contributor A:
I had that same problem on some stair treads that I was in a hurry to install. I bought some 2 inch Celetex panels and made a small 4x4x8 hot box, installed it in a shipping container, and put my stair treads in with a propane heater and a big compost thermometer. I got the interior pile to about 170 degrees and held it there for 10 hours. When I opened it up, the little grubs were on the ground dead. My only problem was I raised the MC of the wood from 10 to 12%, but I live on the coast and the MC in my house is 12%, so I could live with that. The propane system added water to the stack. But the bugs were dead!

Imagine my shock as I was routering the end of a stair tread and the vibration sent one grub wriggling to the surface... buggy wood in a brand new home. That's when I had to make the hotbox.