heavy 2x's ?? Moisture?

[Will Blick]

Bought a bunch of nice 2x4 x10 at Lowes... kiln dried, nice wood...
I noticed some of the boards weighed substantially greater than others.... maybe 1.5x, just guessing... I am curious, is this a wood density issue, or is it a drying issue? They all appeared equally dry...did not have moisture meter... I don't buy much construction lumber, so just curious, cause if is moisture, I am sure the heavy ones will twist n shout...

[Chris Padilla]

Yes, moisture.

[ray hampton]

the best test for the density of wood is to drive a nail into the wood without bending the nail, some soft wood are harder than other

[Chris Tsutsui]

199712

I bought a 4x10 from Home Depot and made this tapered plug from it with band saw, disc sander, and lathe. (For those curious it's a plug for a hollow stem auger drill rig), however it only took a day for the wood to split open 1/8th to 1/4" as it dried.

I also found that multiple coatings of polyurethane didn't help at all either for I should have used some type of wax or wrap it in plastic wrap or something... It's like I have to treat the Lowes or Home Depot building lumber as being WET.

[Richard Wolf]

Kiln dried construction lumber does not equal kiln dried hardwoods. Hardwoods should be between 6 and 9 percent. Construction lumber will be considerably more.

[Kevin W Johnson]

199712

I bought a 4x10 from Home Depot and made this tapered plug from it with band saw, disc sander, and lathe. (For those curious it's a plug for a hollow stem auger drill rig), however it only took a day for the wood to split open 1/8th to 1/4" as it dried.

I also found that multiple coatings of polyurethane didn't help at all either for I should have used some type of wax or wrap it in plastic wrap or something... It's like I have to treat the Lowes or Home Depot building lumber as being WET.

That appears to be treated lumber, which usually has a very high moisture content when purchased. MANY times when i have purchased treated lumber, alot of it in the store still wet to the touch

[Frank Drew]

199712

I bought a 4x10 from Home Depot and made this tapered plug from it with band saw, disc sander, and lathe. (For those curious it's a plug for a hollow stem auger drill rig), however it only took a day for the wood to split open 1/8th to 1/4" as it dried.



Chris, construction lumber, particularly dimension lumber, often includes the pith (wood from the very center of the tree; note the growth rings in your photo); splitting at the pith is so common that it should be expected.

[Brian Tymchak]

Kiln dried or not, a lot of dimensional lumber at the BORGs is stored outside in the rain until it is needed inside. some of the boards you picked may have been on the exterior of the bundle.

[Ed Labadie]

Moisture is a possibility, but, since const. grade lumber is "SPF" meaning Spruce, Pine, Fir, some of the boards could be different species of wood.

Ed

[ray hampton]

Kiln dried or not, a lot of dimensional lumber at the BORGs is stored outside in the rain until it is needed inside. some of the boards you picked may have been on the exterior of the bundle.
WHY pay to have the lumber KILN-DRIED if they store it outside where it will soak -in the rain

[Will Blick]

great responses, thx guys, lots of things I haven't thought of...
the pick came from the center of dense pile, so I doubt rain was the issue, otherwise they all would have absorbed the same...

I think what Ed mentioned might be feasible, but the density diffference of these woods are within 15% with a quick google search... the weight differences is clearly 1.5x range, not 15% which would be barely detectable...

My thought was, the heavy boards seem to be sap wood (outer most rings) .... but not sure if sap wood can be this wide on a these trees - that it would encompass the entire 2x4 board? If so, my guess is, the sap wood is inherently higher moisture as it is the water delivery system... gotta find my moisture meter...

[Cody Colston]

Construction lumber is typically kiln-dried to 20% moisture content. That level of dryness is to reduce shipping weight as much as it is to dry the lumber.

I've never seen Borg lumber stored outside, uncovered. Actually, I've never seen any lumber yard store lumber outside uncovered.

[Andrew Pitonyak]

If you live near Columbus Ohio, we can check them with my moisture meeter....

Obtain nice scale.
Cut a piece of wood.
Weigh wood.
Repeat
Bake wood at about 100C or 200F
Weigh wood.
Until weight does not change.

The moisture content is (Original Weight - Final Weight) * 100 / (original Weight)

My moisture meeter would want the density, so this is perhaps more accurate :

[Frank Drew]

I live right on a freight rail line; for a long time I'd see bundles of construction lumber unwrapped on the flatbed (open) rail cars. Then for years, lots of wrapped bundles, but lately I've been seeing unwrapped bundles more and more.

[Will Blick]

Well, I checked the lumber with two different pin meters....the heavier boards were 16% on avg, the light weight boards were 10% on avg. Now, does this alone make a board nearly 1.5x heavier? If they answer is yes, quite surprising.

and when the moist boards loose water, will they also shrink in size and no longer be of standard 2x4 dimension?

I am curious, when it says 10% moisture, what exactly does this mean? 10% of the volume of the board is water?

[Andrew Pitonyak]

I am curious, when it says 10% moisture, what exactly does this mean? 10% of the volume of the board is water?

That is 10% by weight. If you look at the formula that I have above, it states that what you really do is



Find out what the board weighs wet (wet)
Dry the board so that you know what it weighs dry (dry).
Calculate the percentage as (wet - dry) / wet

This is based on weight, not volume. Oh, and really, you need to multiply by 100 because 12% is represented as 0.12.

What do you have when you take (wet - dry)? You have the difference in the wet board and the dry board. This means, that you have the weight of the water. So, if your board weighs 100 pounds wet and 88 pounds dry, then you have 12 pounds of water in that board (big board I assume).

100 - 88 = 12 and 12/100 = 0.12 = 12%

[Will Blick]

thx Andrew, I missed your previous post.... ok, its by weight... makes sense, hence why one of my meters needs the woods density...

so what happens to a 2x4 when all the wetness dries out, will it maintain its 2x4 dimensions? I would think it would shrink?

[Andrew Pitonyak]

I am not an expert, and I will not bother to verify that numbers bouncing around my head, but I believe that....

Wood does expand and contract as MC (Moisture Content) increases and decreases. I expect that the length change will be minimal (say 0.01% Longitudinal). As for the 2x4 directions, that depends on how the grain runs. As a general rule, I expect that you might see say 4% radial change (think about the grain as paper and this runs up and down the stack) and 8% tangential (across the face of the paper).

A rule of thumb is that if the board shows mostly flat grain on its face, allow for 1⁄4 inch total wood movement for every 12 inches across the grain (about 2%) for change in humidity. For quarter sawn, maybe half that.

Note: I am inexperienced, but I read a lot.

[Brian Tymchak]

WHY pay to have the lumber KILN-DRIED if they store it outside where it will soak -in the rain

Don't ask me... But they do it. I've watched them bring the bundles in dripping water. Maybe it's just my BORG..