KD vs. green lumber

[Victor Robinson]

I was purchasing some studs for a reno project recently, and observed a paradoxical situation I'm hoping to get cleared up.

Whenever I've needed studs, I've always purchased kiln-dried stuff. It's more stable and usually in significantly straighter condition. The orange borg sells KD studs for just under $3 per, but sells GREEN 2x4s for a couple of dimes more. Why in the world is this? My understanding is kiln-dried is SIGNIFICANTLY better for anything structural (and specified by many codes), and even more so when we woodworkers use building lumber for shop use. So why does the green stuff cost more, and why would you use it over the KD?

Thanks for clearing this up for me.

[Pat Barry]

Outdoors, ground contact, etc

[Jamie Buxton]

Generally KD lumber is more expensive than green lumber in the same species. Sometimes a yard gets a good buy, and the prices invert for a while, but they eventually go back.

Green lumber is easier to drive nails into, and it has a smaller tendency to split when nailed, so builders like it. And, as I said, it is generally less expensive than dried lumber of the same species.

You may be looking at two different species. Often on the west coast, the green studs are Douglas Fir, and the KD stuff is dunno wood.


Here's a tip about KD construction lumber.... The industry standard is that it is dried down to 19% EMC. That's dry enough that mold won't grow on it. However, wood inside houses generally dries down to 9% EMC or so. The KD construction lumber is going to get down to that level eventually. As it goes from 19% to 9%, it will shrink some and it may warp.

[Jim Andrew]

If that green lumber is douglas fir, it stays straight better than any other species. And is a lot stronger.

[Mel Fulks]

It's not clear whether this is about pressure treated or just regular undried wood .I do realize that big box stores have different inventory than east coast.Anybody know what's going on??

[Victor Robinson]

It's not clear whether this is about pressure treated or just regular undried wood .I do realize that big box stores have different inventory than east coast.Anybody know what's going on??

No, we're not talking pressure-treated...just dry vs. wet.

I know in general KD lumber should be more expensive, but I've noticed this trend at my local orange stores for at least a year (the KD being less expensive). It probably is a species thing as Jamie and Jim point out. The KD stuff is Hemlock, which from my understanding isn't quite as good as Doug Fir (but not as bad as "dunno wood," or "whitewood" and the green stuff was Doug Fir. That being said, all theoretical properties of the two species aside, the green DF stuff was twisted, warped, and plain ugly. The KD hemlock was very straight. To put it into perspective, ONE PASS (and I do the minimum...1/64") on the jointer flattened the face on most of the studs. Granted, this was from a HD Pro, so their stock of KD studs may be better (and stacked properly) than the average HD.

Great info re: MC from Jamie -- thanks.

[Mel Fulks]

Thanks. I didn't have any idea what the norm was there. The Doug Fir kd 2x4 available here typically have a lot of sap wood,buy 2x6 and you get a little better quality ,2 x8 better still. I wonder if the fir you are talking about is real high in sap ,and other defects. The sap woods are worthless outside unless chemically treated.