More about air dried lumber and powder post beetles

[Phil Thien]

So I had another thread where I asked about solutions to possible PPD infestation.

Looking into the matter, I see there are quite a few different types of beetles that infest this stuff.

My question today is, what else can you tell me about your experiences (if any) with insect infestation?

I known kiln drying will kill them (and more importantly, the larvae).

I'm just wondering if anyone has ever meet w/ disaster in using air-dried lumber.

There was an article in the newspaper in the last year or two about a couple that built a new house. They had filed a lawsuit against the supplier of the flooring (a big box that rhymes with "Benards") because they said the flooring introduced some sort of beetle that was eating all their wood.

Some basic questions: Can the insects work through the entire piece? It would seem to me that they can, as some pieces I've inspected seem to have it in the heart wood as well as the sap wood.

Are there any rules of thumb as to age of the wood? It seems (from reading) that green wood is more apt to get the bugs. But, if piles of lumber sit for a long time (10+ years) they can be totally infested.

Are there any species of wood that the bugs don't particularly like?

[John Keeton]

Phil, I have found that powder post beetles enjoy poplar immensly, as well as maple. On walnut, they seem to avoid the heartwood. Haven't had any evidence in the white oak I have, nor red oak - not sure if that means anything. I have some ash that doesn't have any infestation. I suspect the responses to your question will have regional differences, both as to the culprits, and the various wood species indigenous to the area, etc.

[Richard M. Wolfe]

Phil, when wood air dries a bit large borers will not infect it. Powder post are the only species that will tackle dry wood, and by dry that means 13-15% or more, which can be air dried or even kiln dried if it has been acclimating in fairly humid conditions. Wood boring insects are ingesting the wood for food, which means a high concentration of sugars and/or starch. The sapwood of a number of trees will be univerally attacked and for some it seems to depend on the invidual tree. I have had ash boards side by side and some got powder post and some not. I have had powder post in a few red oak boards but very few. I have never had (or heard of) powder post in soft woods - pine spruce, etc.

[Phil Thien]

Good feedback so far, thanks.

How what is the exact mechanism by which these guys work?

I've read the holes I see are the exit holes of the beetle. But how did they get in there to begin with?

The reason I ask is, I wonder whether taking rough sawn lumber and immediately making it S4S (so remove bark and sap wood, plane both sides and rip both edges straight) will help in minimizing any possible damage. If I inspect the resulting piece of lumber, and see nothing both smooth grain with no irregularities, am I likely to be safe? Or are the eggs somehow teleported further into the lumber in a way that I can't see?

[John Keeton]

I wonder whether taking rough sawn lumber and immediately making it S4S (so remove bark and sap wood, plane both sides and rip both edges straight) will help in minimizing any possible damage.I can answer no to this idea. Don't think it will make a difference except as to removal of sap wood of certain species.

The powder post problems I have experienced have shown up after passage of time in wood that I have had for several years - most rough cut, but some S4S. It seems to be selective, as Richard notes. I have several stacks of different woods in my barn, and have found damage in maple that was right next to ash with no damage. I have found damage in some walnut sapwood in a large stack of walnut next to poplar that has damage - which would seem to say they will migrate to adjacent wood if it seems palatable.

I think pretreating all wood with borax may help prevent problems, but since I work mostly with walnut and oak, I haven't seen the need. If/when they get in my curly maple, I will not be happy!!!

[Richard M. Wolfe]

Powder post are just about everywhere. By everywhere I don't means hundreds per square foot but if there is a good meal around they will eventually find it. The adults lay eggs on wood and when they hatch the larvae bore into the wood. The entrance hole would be so small as to be unnoticeable. I think (a pHD in entomology told me but I've slept since then :o ) that the adult pupates near the surface, emerges and then finishes chewing its way out. How it knows where the surface is I don't have a clue.

Certainly taking the sapwood off will help avoid 'beetle contamination'. But since the powder post go into the heartwood only a small distance I usually just cut out any powder post damage I see. I don't have working knowledge of all woods by any means but the only one I know of commonly getting heartwood infestation is ash. Also, if you spray the surfaced wood with a borate treatment you can eliminate powder post worries. When the eggs hatch the critters ingest the borate which is on the surface and die as they try to go deeper. A borate treatment is no good for larvae already in the wood as it does not penetrate deeply enough.

[roman fedyk]

Everything you might want to know about woodborers you can find here at the University of Florida study about powder post beetles, etc.:


http://edis.ifas.ufl.edu/pdffiles/IG/IG11900.pdf

[Phil Thien]

Everything you might want to know about woodborers you can find here at the University of Florida study about powder post beetles, etc.:


http://edis.ifas.ufl.edu/pdffiles/IG/IG11900.pdf

Yep, that is a good reference.

[Phil Thien]

The entrance hole would be so small as to be unnoticeable.

That sucks.

The cherry I was looking at had damage at the sapwood, and I was able to cut it away.

I was told the other stack of wood was beech. The damage to that wood looks far more extensive (with damage to much of the hardwood). It wouldn't surprise me to learn that it isn't beech, but ash.

Not a wood species expert by any stretch.

[Phil Thien]

So it seems like lots of people use air-dried lumber. But I haven't heard of any instances of these things emerging and eating some one's house to the ground. Are they until termites in that regard? Are they just annoying and a little destructive?

The mental imagine I have is making a small table, only to have hundreds of the things emerge from the wood months later and start chewing on my flooring and getting into my floor joists and studs.

[John Keeton]

Phil, my method of dealing with this is to simply not use damaged wood. It goes in the firewood pile. Since nearly all my wood is rough sawn, infested wood becomes readily apparent when jointed or planed. I am not sure that there is that much risk of what you envision, but why tempt fate! In reality, these bugs exist in the environment, and could infest your framing anyway. They won't bother finished wood.

I looked at the other thread a few days ago, but don't recall - is all of the wood you want to use for the table infested?

[Phil Thien]

I looked at the other thread a few days ago, but don't recall - is all of the wood you want to use for the table infested?

Oh, the table is theoretical. Not building a table.

I found a huge quantity of air-dried lumber that had been sitting in a barn for 20 years.

I was told it was about 150 sticks of walnut, and another 150 sticks of beech.

When I went to look at it, I didn't find much walnut. It was cherry, and beech (can't confirm the beech, I'm thinking it may be ash). The cherry is nice looking stuff.

BUT, the bark was left on some of the boards and under the bark and into the sap wood is obvious PPB damage. I just looked at a few boards on top, and I took a few home, and thought, "what can I do with this, can it be used? Is it safe to bring into my basement shop?"

The beech (or ash) had smaller holes, quite a few of them and they were found all over the boards, no just the edges. But if I knew the bugs were done, well, the wood has nice character and would be great to use.

And then my thinking turned to more general "is air-dried lumber safe at all?" I certainly don't want to end up introducing a wood-hungry insect to my home.

[John Keeton]

Phil, when they infest maple or poplar, it seems to be throughout - as you stated regarding the beech/ash. When that happens, I normally find that all adjacent boards are likewise affected. But, I have never seen widespread devastation in a piece of wood, and perhaps that has as much to do with locale as anything. I have had maple or poplar show several trails through the wood, but not so much as to affect the structural integrity of the wood like termites would do.

Keep in mind that termites don't normally live in the wood, but travel in multitudes to the wood for a food source, and nest underground. We are talking large numbers here compared to what I see in PPB.

I would have no interest in buying or bringing home wood that was infested. Although, I guess it is possible that PPB have a certain reproductive cycle that may be generational such that all of the larvae mature at the same time?? Not sure on that one, but if true, could make the wood safe.

I know that eventually, the wood I have in the barn may become infested if not used beforehand - at least the poplar and maple. Obviously, the bugs are there, and have been for many years. I have seen a little damage to some of the timbers - but very minimal.

I have not seen damage in my walnut, cherry, oak or ash, so my concern is limited. I have very little poplar, but the maple is all curly and I hate to think about it being damaged.

Interestingly, for the last 3 years, I have the barn sprayed each spring - inside and out - with Demon for carpenter bees. It works very well - so well, in fact, that there are no spiders, no wasps, etc. It may deter the PPB. I can only hope!

[David Helm]

Just found this thread. Phil, you can worry about your hardwood floors, but, unless your framing is a hardwood you shouldn't have anything to worry about. Lyctids, commonly known as Powder Post beetles, eat the starches in hardwoods. They also like grass; aka bamboo. Framing lumber, generally softwoods like fir, hemlock or pine are attacked in some areas (mine) by another beetle known as the Anobiid. They are not common in other parts of the country. Really only the maritime northwest. The story about box store hardwood floors being infested is true. Many imported hardwoods don't spend much time in the kiln, so the eggs and larvae are not all killed. When the wood comes out, they get active again.

[Leigh Betsch]

So are these powder post beatles just a southern thing or do they infest wood up here on the north side of the deep freeze zone? We don't seem to have as may crawly things up here cause they can't escape the cold weather. Come to think of it maybe that's what happened to all the trees is South Dakota!

[David G Baker]

A friend of mine in Mid Michigan was renting an old farm house with 4 barns on the property. Every building was in terrible shape due to powder post beetles. The finished floor in the house had small holes in it where the beetles were emerging. The front porch had collapsed the barn support beams had piles of powder around their base. I have never seen an infestation this bad.

[Frank Drew]

Thankfully I've never had termite issues in my shop or with my lumber, but I have had powderpost beetle infestations, with kiln dried ash the most affected. What damage I had to walnut and cherry was for the very most part limited to the sapwood. I've never had losses sufficient to turn me away from air-drying some stock, though.

[Andrew Joiner]

I've done woodworking in Minnesota and Oregon with air dried and mostly kiln dried.
The only time in 40 years I saw any bugs was in some kiln dried maple.I cut off the bored holes and saw some fresh activity a few days later so I cut that area off. When I oiled it the final product with Danish oil I saw no more bug evidence.

For fun I tested the actively infested scraps with Danish oil. I was amazed to see the little critters scurry around trying to put on their little respirators.:)

[Curt Harms]

an inspection for termites and powder post beetles. Of course a lot of older houses were framed with whatever wood grew locally. Around here it was mostly hardwoods so yes, house framing can be infected by powder post beetles. Though it sounds like it would also require moisture problems as well.

[Jim Mackell]

So it seems like lots of people use air-dried lumber. But I haven't heard of any instances of these things emerging and eating some one's house to the ground. Are they until termites in that regard? Are they just annoying and a little destructive?

Phil, we use air dried ash in restoration work. We recently had reason to pull off a floor cover that had a replacement ash cleat installed under it about 5 to 10 years ago. What was left of the cleat was a very fine powder. More like talc than flour. While we have never seen a powder post beetle, we have seen the tremendous damage they can cause. If you even suspect their presence, I would not use the wood or keep it around your current supply unless you can get it kilned.

[Frank Drew]

As far as I know, termites will eat any wood product, but powder post beetles prefer sap wood because that's where the sugar is, and that's why they like ash, because ash features a small heartwood to sapwood ratio (the white, desirable portion, is sapwood. Ditto with maple.)

[Scott T Smith]

Although powder post beetles prefer sapwood, I have seen many instances of them being present in the heartwood of both red and white oak. In some instances, I've seen the holes more than 12" in from the bark, and well into the heartwood.

[Neal Clayton]

an inspection for termites and powder post beetles. Of course a lot of older houses were framed with whatever wood grew locally. Around here it was mostly hardwoods so yes, house framing can be infected by powder post beetles. Though it sounds like it would also require moisture problems as well.

old buildings were treated with boric acid. boric acid has been used for centuries, for everything from treating furs and leather to treating food stored for the winter, pre-refrigeration.

it also kills mold and mildew, but otherwise just insects. it's harmless to people. the wood absorbs it like it would any other sealer, so it won't affect any finish you might use. there's a modern equivalent called 'boracare' you can order online.
(http://doyourownpestcontrol.com/spec/pick-boracare1.htm)

[Larry Edgerton]

So are these powder post beatles just a southern thing or do they infest wood up here on the north side of the deep freeze zone? We don't seem to have as may crawly things up here cause they can't escape the cold weather. Come to think of it maybe that's what happened to all the trees is South Dakota!

We have them up here too Leigh. The 130 year old oak post and beam barn at the place I am working has enough holes visible that you and I could both retire if we had a penny for each one.

I spray my stock with a Borax solution if in question, and generally buy only kiln dried from reputable sources. [No box stores!] Fruitwoods seem to be their favorites along with ash around here.

[Loren Bengtson]

BUT, the bark was left on some of the boards and under the bark and into the sap wood is obvious PPB damage. I just looked at a few boards on top, and I took a few home, and thought, "what can I do with this, can it be used? Is it safe to bring into my basement shop?"

The beech (or ash) had smaller holes, quite a few of them and they were found all over the boards, no just the edges. But if I knew the bugs were done, well, the wood has nice character and would be great to use.
Phil,
If the damage was under the bark and you did not find any holes into the wood itself it’s quite possible that it was not PPB (Powder Post Beatles), but EAB (Emerald Ash Borer).

EAB larvae eat a maze of channels just inside the bark of ash trees. They do not tunnel into the wood. PPB’s do eat holes into the wood.

One identifying characteristic is the EAB’s "D"-shaped hole. The PPB leaves a round hole which is a little larger (but if you don’t have the two side-by-side, it’s hard to tell what size hole you have). Also, PPB usually leaves piles of frass outside the wood, while EAB leaves no sign except for the hole.

Although EAB is a terrible threat to live ash trees, they will not attack wood without bark, so if it is EAB, your home and projects are safe as long as you get the bark off the lumber.

One last point: DO NOT transport firewood or lumber with bark on it. This is the main way the EAB is getting spread around the country. EAB’s are killing our ash trees just like the blight killed all the chestnuts about 100 years ago.

– Loren

[David Keller NC]

That sucks.

The cherry I was looking at had damage at the sapwood, and I was able to cut it away.

I was told the other stack of wood was beech. The damage to that wood looks far more extensive (with damage to much of the hardwood). It wouldn't surprise me to learn that it isn't beech, but ash.

Not a wood species expert by any stretch.

Phil - If you're looking for a method that will allow you to sterilize a large stack of lumber before you bring it inside, there's a way that most WWs can handle. Although solutions of borax will certainly keep PP beetles and other nasties from infesting the wood in the first place, I would be leary of trusting it to kill everything within an already infested stack because the solution won't penetrate the holes (the holes are too small and the surface tension of the borate solution is too high, even with surfactant added to it).

Essentially, you use gaseous ammonia to fume a stack of lumber at a time, and it is 100% guaranteed to kill absolutely everything within the wood, including fungi, bacteria and any insect eggs. To do this, you need to stack and sticker the wood on a driveway or a ground surface where you don't care whether the plant life below gets killed. It's essential to sticker the lumber for good gas penetration. Cover the stack with at least 3 mil thick painter's plastic. The plastic must be continuous - no seams. Potentially, you can tape the seams with aluminum HVAC tape, but there can be no leaks.

To seal the stack, shovel sand or dirt on top of the portion of the plastic sheet that's on the ground around the perimeter of the stack.

Buy some janitorial strength cleaning ammonia (this is 10% ammonia solution for sale at Ace hardware stores). 30% ammonium hydroxide works even better, but is harder to come by and more dangerous to work with. Pour about 2 quarts of the ammonia into a shallow plastic pan and place it underneath the sheet. Leave it for 2 days, remove the plastic, and allow the stack to air out before bringing it inside.

Note: Getting a lungful of even the 10% janitorial ammonia can cause severe burns to your mucous membranes (sinuses, throat, and lungs). You absolutely must wear an activated charcoal respirator, heavy gloves and safety glasses to do this - you can get a respirator at Lowes or Home Depot for about $15 - $20.

[David Helm]

You should know that fuming with ammonia will change the color of the wood. Stickley used ammonia fuming to get the dark color on his white oak furniture. . . . and it is very dangerous.

[Ted Wong]

I've had several infestations of PPB in the past and the one treatment I've found that is inexpensive and does a good job has been Termite Pruf. It contains borate which will kill any larvae munching their way in or out and preventing a major infestation by breaking their life cycle. All it takes is a thin barrier at the top surface to keep an infestation from occurring. I apply the material with a garden sprayer soon after having a tree cut up.
I use to have logs cut up and have left the bark intact. This is a big no no as it provided cover for any bugs already in the wood. Now I have the bark and sapwood stripped at the sawmill and spray as soon as I get it to my location. I've also found a screened enclosure helps keep the bugs down and allows good airflow.

[David Keller NC]

You should know that fuming with ammonia will change the color of the wood. Stickley used ammonia fuming to get the dark color on his white oak furniture. . . . and it is very dangerous.

Indeed, though with cherry and oak, many view this as desirable. "Very dangerous" of course, is a relative term. It's considerably less dangerous than darkening wood with nitric acid and/or potassium dichromate, and less so than many of gaseous organophosphate insecticides.

That said, ammonia fuming without a respirator or indoors is asking for trouble.

[Andrew Peters]

I am hoping I get lucky here. I have a large quantity of HW Maple in my shed that I acquired from a local wood shop that went out of business. I live in WI and this wood has sat for two years through spells of heat to 110 degrees and freezing temps 10 degrees and below for days. I read in a study online that cold of 10-15 degrees F for 72 consecutive hours will will kill the PPB.

I am building cabinets and noticed a TON of worm holes. There are larger networks in areas near sap wood and very few near the heart. I've planed, re-sawed and cut a bunch and haven't seen one beetle. I took a course plastic brush and cleaned the fine powder out of the holes and I don't mind the look. I'm not sure if the wood has ever been kiln dried either. Am I setting myself up for disaster?

I'm almost ready to burn it all.

[Phil Thien]

I am hoping I get lucky here. I have a large quantity of HW Maple in my shed that I acquired from a local wood shop that went out of business. I live in WI and this wood has sat for two years through spells of heat to 110 degrees and freezing temps 10 degrees and below for days. I read in a study online that cold of 10-15 degrees F for 72 consecutive hours will will kill the PPB.

I am building cabinets and noticed a TON of worm holes. There are larger networks in areas near sap wood and very few near the heart. I've planed, re-sawed and cut a bunch and haven't seen one beetle. I took a course plastic brush and cleaned the fine powder out of the holes and I don't mind the look. I'm not sure if the wood has ever been kiln dried either. Am I setting myself up for disaster?

I'm almost ready to burn it all.

Interesting thread to revive.

Autumn before last, there was an add for cherry lumber. It looked like quite a bit but it was hard to make out the pictures. $200 + $25 for delivery. I called and told them to "bring it."

When it arrived it was white oak, and had suffered quite an infestation at some point. $100 was agreed upon as the price. I figured I could make some outdoor furniture with it, the holes would give it character.

It went into the garage and then we continued to have a very cold winter. I did research that indicated the same thing as you (super-cold temps and I think the colder the better for three to four days) would kill them.

Come spring and summer I checked the wood and I can see no signs of current infestation. I looked for evidence of anything emerging from the lumber and can't find anything.

I haven't used the stuff yet, I will be this next summer.

But I'm pretty sure super-cold does the trick.

BTW, I had already decided that if I didn't have a cold enough winter, that I was going to stuff the wood into the drive-in deep freezers belonging to my friend's business. It was either that, or pay for kilning.

[Bradley Gray]

In my area red maple ash and poplar are the favorite foods of the PPB. I have an EBAC dehumidification kiln but still get PPB survivors. I have had good results with BoraCare applied liberally to suspect boards.

[Andrew Peters]

Is BoraCare something I can apply to the wood at this point indoors? How long would I need to let it dry? From what I have read I will keep it and brush out the grooves and embrace the grooves.

[Phil Thien]

In my area red maple ash and poplar are the favorite foods of the PPB. I have an EBAC dehumidification kiln but still get PPB survivors. I have had good results with BoraCare applied liberally to suspect boards.

I don't think dehumidification kilns help w/ beetle infestations, you need heat or freezing.

[Bradley Gray]

My point exactly. My kiln tops out at 45 celsius (113F) and I have survivors.

I have used boracare on work in progress and finished parts indoors with a few days dry time.

[roger wiegand]

Shortly after moving into our new place we had a PPB hatch in our barn-- they had infested the floorboards of the loft and the surface was covered with newly hatched bugs, and the floor below was black with them. The pest control guy we had out said he'd been in the business 45 years and never seen anything like it. I applied ~80 gallons of Boracare, coating every wood surface on all sides with a garden sprayer and four years later have not seen a single beetle. Since the barn is now my wood shop I sincerely hope they are gone!

[Jim Andrew]

I have found some boards infected with PPB here in Kansas. You can recognize them by the fine dust that has fallen out of the board onto the piece underneath. What I did was go through the pile, took out all the infected boards, burned the low quality boards and put the better ones in an old metal grain bin. After going through a summer in the bin, found the boards were no longer infected. Those old grain bins get hot inside, unless there are trees shading them.

[ryan paulsen]

As I have a couple stacks of white oak currently air drying, I'm glad this thread came up. Interesting about the cold killing the PPBs, but I wonder if this is the case, how do they survive the winters in "the wild?" I hope it's the case, since with the weather we've had this winter, anything that can die from the cold will be dead!

I have also heard of adding a couple 250W heat lamps to an insulated box (ie duhimidification kiln) to bring up the temp for a sterilization cycle. Has anyone done this? This to me seems to be a more desirable option than spraying with borax.

[Scott T Smith]

I would like to jump in and correct a few misconceptions.

First - all commercial DH kilns will get hot enough to sterilize the load at the end of the kiln cycle. USDA specs call for heating the core of the lumber to 133F for 30 minutes or greater, which typically requires a chamber temp of 140 - 150F for several hours. This temperature is sufficient to kill both active infestations as well as larvae / eggs that are present in the lumber. It is standard industry recommended practice to sterilize the load at the end of the kiln cycle.

Some of the smaller DH kilns which are purchased by woodworkers may not heat high enough to sterilize, but that is not representative of the commercial models.

Second - regarding using Boracare in lieu of heat sterilization, the only method approved by the USDA is heat sterilization. Boracare is primarily marketed for the owners of log cabins to apply to the exterior of their logs.

The drawback against using a liquid product to sterilize is that any time that you significantly rewet lumber you will cause the wood cells to expand as they take on moisture. Then, when they dry out they will shrink and in many instances surface checking will result. So Boracare may kill the PPB, but at a risk of causing surface checks on your boards.

It is very easy to build a home sterilization chamber for treating pests. All it requires is some foil backed foam board, a couple of sawhorses, a pair of meat thermometers, some duct take, a small space heater and your lumber/stickers. Christian Becksvoort wrote an article about this in the October 2008 issue of FWW.

This is not a system for drying green lumber, but it is an effective way to sterilize lumber that has already been If anybody is interested send me a PM with your e-mail address and I will send you the information about building your own sterilization chamber.

[Rob Damon]

I have about 500bf of red oak, some air dried, some air dried, all was still rough and all at -6-8 %. I noticed the powder by several of the 12/4 boards several years ago. I went ahead and milled all of the boards down to see which had infections, which did not.

Boards with no holes were treated with timbor, since it is described as surface treatment blocker for unaffected wood. If bugs eat the surface wood to get into it, they will die before laying eggs.

The boards with holes I treated with Bora-care, which is described as a penetrating solution, that will leece deep into the wood killing bugs/eggs that are already in the wood. I did that several years ago and have not had a single recurrence.

Both timbor and bora-care are applied as a liquid and I have not had any surface checking issues. (I.E. think in terms of applying a liquid finish, have you every had surface checking after applying a liquid finish?)

Of the 50 plus other species in my controlled climate wood storage area (about 5000 bf worth), I have not seen any other infections.



Rob

[Andrew Peters]

For those that embrace the beetle tracks, how have you finished it? I have HW Maple and there is a good amount of PPB damage, but nothing to take away from the structure. I used compressed air to clean the holes and grooves out. I am thinking about white washing the wood and sealing it. Then coming back with a gel stain to fill in the beetle holes with a slightly tinted whitewash.

What have you done?