2X4's

[David Scigliano]

I am building built ins, and will be putting 2X4's in a niche where the Built in is going. The 2X4's will be out of site. When I went to the lumber store I noticed there were many types of 2X4,s with different prices. Which 2X4'S should I use.

[Travis Johnson]

The classifications that I know of are listed below, then let me try to explain the four types:

Economy
Surfaced Dry
Kiln Dried
S/F/P and Pressure Treated

Economy 2x4's are pretty much the dregs of the lumber world. They are full of knots, bark, wane, twist and shake. You can build stuff out of them, like dog-houses, fences and other structural elements, but being as crappy as they are, it takes a lot of time and frustration that may, or may not, be worth it. Inevitably, these will be surface dry, but for more on that, read on.

Surface dry means the lumber comes off the sawmill and is placed outside to dry. They don't touch a kiln and for a few weeks are allowed to sit in a big yard and dry out. The only reason for this is to reduce their weight. Freshly sawn lumber can be almost 50% water, so it makes little sense to pay high transportation costs to haul wet lumber.

Now Surface dry means just what it says. It is not uncommon for lumber to be very wet inside. Many of us have used this lumber and seen beads of water squeeze out around nails and cuts. This occurs when the mills need to fill an order and cheat the drying time a little. In most cases it means very little because this lumber is destined for structural use where once it is secured in walls, floors and other structural ways, it will not warp and twist while it drys itself out even more.

Kiln dried wood is designed to have most of the water dried out when you buy it. It is a higher quality product because if the wood is going to shrink, twist or bow, it's going to do that in the kiln. Under the closely watched conditions inside a kiln, consider this wood pampered, but not nessisarily the first 2x4's to buy.

Kiln dried wood is only as good as the conditions it is stored in. Water is like a sponge. Place it outside in a wet and rainy day, and it will absorb moisture. Place it in the sun, and it will dry out. The problem is some lumber retailers treat Kiln Dried wood as if it is surfaced dried wood, that is letting it sit outside. I saw this just the other day, making the whole kiln-dried process obsolete.

Now the majority of the lumber you get says S/F/P or Spruce/ Fir/ Pine. This is standard grade stuff and can be either surfaced dried or kiln dried. Pressure treated wood is usually Southern Yellow Pine that has chemicals injected at high pressure. It is expensive, but resists rotting.

Now if you are still reading this, here is the good part. If you are going to be building something structural, like a wall, floors or stairs in an inside environment, and want fairly straight lumber without paying to much, Surfaced Dried S/F/P is pretty hard to beat. It should say Surfaced Dr- S/F/P right on the sawmills ink stamp.

Hope all this typing was what you were looking for...

[Per Swenson]

Douglas fir.

Per

[Frank Pellow]

Good summaryTravis!

I do have one commnet on your statement: "Pressure treated wood is usually Southern Yellow Pine that has chemicals injected at high pressure. It is expensive, but resists rotting." This is regional. Here in the Toroonto area, the pressure treated wood is mostly Ontario or Quesbec grown spruce.

[tod evans]

Douglas fir.

Per

agree 100% the only structual 2x material i use! generally not available at the borgs....02 tod

[Steve Schoene]

I'll second the motion not to buy from the borgs. About 80% of the 2x4's I see there contain the pith (center of the log), which is a sure receipe for warping. A real lumber yard is likely to have better stock. Tell them what you need it for--service is what makes a real lumber yard. Only a few of them aren't interested in small customers--most will be very helpful.

I would go with the K-D (at least if it has been stored under shelter) since even so, the wood is going to have more moisture than it will reach in use indoors. This is not as important if the lumber is fully secured--ie. nailed in place top and bottom, so it can dry without warping.

The species doesn't matter much since it is doubtful you need the extra strength of D-fir. By the way, at my local borgs most of the Douglas Fir is sold labeled Grn (Green), which means it initially had more than 19% moisture content. (Indoors wood will generally reach about 8% more or less depending on season.)

[Jim Becker]

My friendly, local, full-service lumber yard has quality 2x material for not much different cost from the 'borg(s).

[Doyle Alley]

Down here, all the 2x4s in the Borg are that generic "white wood". I have yet to find a listing for a "Whitewood Tree" in any forestry guide. The only thing guaranteed about it is that it is going to warp. It is all center pith wood and flat sawn.

The local lumber yards don't seem to stock stuff that is much better. It's so bad that when it is time to make my shop benches and lumber rack, I'm going to make my own 2x4s by ripping down 2x10s. At least with a 2x10 I can find SYP with diagonal growth rings. It will cost a little more, but at least it will be stable.