Worm Holes and Lumber Grading

Bug holes aren't a lumber defect in everybody's eyes it all depends on your market. Here's some info about how grading standards account for insect damage. December 9, 2010

Can anybody advise me of the impact that the presence of small holes from powder post beetles have on the grade of a kiln dried hardwood board (such as 5/4 quartersawn oak)? If I'm reading the rules correctly, a board that would otherwise grade as FAS or Select is reduced to #2 or #3 Common if PPB holes are present?

Forum Responses
(Sawing and Drying Forum)
From contributor F:
The holes are defects. The best bet would be to make arrangements with the buyer for clear wormy product, if the holes are such that they could be used for paneling etc.

From contributor T:
Im probably not telling you anything you don't know, but you don't necessarily have to look at that wood as defective in every market. So you can't sell it as #1 grade lumber, but many craftsman and artisans look for wormy-this or wormy-that for certain projects. When I first started trying to manage blue stain I was pretty dejected, because I never did find any way to completely eliminate it other than sawing and stickering within a few days of felling.

At first I would mark it down until I realized I had a lot of repeat orders for it. Fast forward to present, I always have a dozen or so that I avoid sawing until the stain has taken a good foothold, because we have a steady demand for denim flame box elder. Although I don't charge a premium for it, I no longer discount it either.

Don't mark your wormy oak down. You'll get as much for it as you would if it were #1 grade. Even if you have thousands of BF of it - if you have the room to store it after drying, you'll eventually sell it at your price and you might get a large order from someone who just has to have wormy oak paneling in their home or lake retreat. As I'm sure you know, with many customers it's all how you describe it. Human nature - some customers will jump all over discounted wood and others will avoid it like the plague because it is beneath them.

From contributor G:

My understanding is that that the Hardwood Grading Association grading rules allow various adjectives to be applied. The one you want is WHND (worm hole no defect). Thus you can advertise any grade with that modification. ie: FAS WHND, #1com WHND, etc. The amazing ambrosia maple is sold by a major supplier here in Indiana as whatever grade WHND.

From contributor T:
From my experience though, unless you're dealing with a broker/buyer or larger furniture shop etc. it's rare to ever even hear the word grade cross someone's lips. They want to look, touch, fall in love with it. If they do and you try to sell them with tech terms, they'll cut you off mid-sentence and ask how long it will take to load. The WHND category sure is nice to know though. I'm sure it would help make a sale with some buyers who do buy on grade.

From contributor A:
Also look for people who do furniture restoration. Sometimes they need oak to do a repair on furniture that has holes in it.

From contributor F:
The WHND grade is typically put up as #1 com and BTR and is used primarily by the upholstered furniture industry. They get the strength of the soft maple at a price a couple hundred bucks a thousand cheaper than the regular. If the wormholes and surrounding discoloration is selected for consistency, it makes a really cool looking floor.

From Gene Wengert, forum technical advisor:
The NHLA has four types of holes (pin, spot, shot and grub) and each is treated differently. Please consider going back the Rule Book to get the correct information. With extensive worm holes, possible grades include 2B, 3A, 3B, Sound wormy and WHND.

Pin, spot and shot can be considered sound. When grading, , if the holes are on one face or they are not all over, it is possible to grade FAS, No 1 or 2A, if the worst face meets the requirements in wood without the holes.

From contributor T:
I know some of you carry your condensed version in your shirt pocket, but for those like me, here it is just so you don't have to go on a hunting expedition like I did:

Pin Worm Hole: One not over 1/16" in diameter.

Spot Worm Hole: One over 1/16" but not more than 1/8" in

Shot Worm Hole: One over 1/8" but less than 1/4" in diameter.

Grub Hole: One 1/4" in diameter or larger.

I guess it would also be correct to just refer to anything under 1/4" as a worm hole and anything over as a grub hole (provided they were caused organically of course).