Ash with old beetle/worm holes

[Rick Potter]

I bought some Ash lumber at an estate sale , and was told it had beetle and worm holes in some of it. I stored it outside on a covered porch with cement floor for maybe 5 years. It came from a hillside basement with a dirt floor when I got it. I was told it was under there for a long time.

I moved it all (15 good size pieces in various thicknesses) and hosed it off to remove the dirt and check for bug action. I see some holes, usually near knots that a pencil fits in, and some worm squiggles that were visible from when they ripped the trunk. I see no obvious new action on the wood.

So...Does the insect attack continue through generations of new insects, on wood that is dead and cut up, or are all the holes as old as I think (hope)? I would like very much to make some small tables and benches out of it. I stored it where I did, because I didn't want to store it in my shop or a wooden shed.

Am I wasting my time?

Should I cut out the wormy areas visible and use the clean appearing wood?

There are some very large knots, that I will cut out anyway, leaving me with 4-6' boards, some 6/4 14" wide, some 4X6, some 4/4 also.

What I want to do is cut the lengths down to 6', clean out the knotty and gnarled stuff and store just the good useable stuff in a metal shed for use.

What happens if I make a bench out of it and a worm pops out next year? Will it eat my house?

Advice appreciated.

[Steve Rozmiarek]

I can't answer all the worries, but I do have some ask in my shop, it's been there for 3 years and it apparently moved into the building with borers. I noticed it first a year ago or so, little piles of sawdust. There is plenty of other wood for them to move into, but that ash seems to be the only thing they like. Over the years the activity has dwindled. I don't see any now, so don't know if they are extinct now or moved onto something else. I'd be curious to know what the little buggers even look like. So far they haven't eaten the shop...

[Steve Demuth]

The only way to certain that there are is no ongoing infestation is to heat treat the wood, but honestly, if it has set for 5 years with no new damage appearing, there probably isn't any infestation. The most common source of damage to cut lumber are the lyctid beetles, commonly called powderpost beetles. If there were an active infestation of lyctids in the wood when you stored it, you would have seen the signs when you unstacked the lumber - piles of very fine sawdust - wood flour fine - where the adult beetles exited the wood after maturing in internal galleries cut in the wood by larvae. Powderpost beetle exit holes on the outside of wood are small - roughly the diameter of a pencil lead.

False powderpost beetles, on the other hand, which often do infest ash, leave a larger exit hole, and it sounds from your post like that might what you're seeing. Some of these have very long lifecycles, so the absence of sawdust/frass in the pile is not proof they are not infested.

Again, the only way to be certain you've got "clean" lumber is to heat treat it. Normally kiln-drying accomplishes this, but you can treat small piles of lumber on your own by creating a plastic tent for the whole pile, and heating the interior tent to 140^oF or so, long enough for all of the wood to reach at least 135^oF for half an hour.

One thing to be aware of - you may have lumber with only a few visible exit holes from powderpost or false powderpost beetles on a board, but discover when you mill the lumber that the internal damage is much more extensive. The lifecycle of these beetles is to lay eggs on the surface or in cracks in the wood, which then hatch and burrow internally, and invisibly, in the wood for 1 or more years, before maturing into an adult beetle, which then makes a single, visible, exit hole.

[Jim Becker]

I agree with Steve...after five years if there is no evidence of activity, such as piles of frass, etc., you're probably good. But I also share his cautions, too.

[Richard Coers]

Powder post beetles absolutely love ash, it's like candy to them. They have 3 stages of life, eggs, larvae, and adults. They can remain dormant for something like 5-7 years. If you needed more bad news, those tiny holes become long tunnels when you run the wood through a thickness planer. I burnt about 1 thousand board feet of soft maple and ash that I had stored in a shed on our farm. The wood was just a mess. Breaks your heart to throw 2"x20"x10' boards of curly soft maple into a bonfire. The wood was just absolutely destroyed. Hell of a learning experience. ABSOLUTELY DO NOT HOPE AND ASSUME THEY HAVE MOVED ON! Here is a good link for info. https://entomology.ca.uky.edu/ef616