It’s because the actual cut is 2x4, and the wood shrinks. The typical shrinkage is known and accounted for. It is a treat when a house has an actual 2x though, i.e., it was cut divided by the shrinkage ratio, or cut dry. Related to why framing is done “on center”, i.e., “16 on center”.
That’s not from shrinkage (well the 1/16 might be, especially newer fast heated junk at the Homely Despot). It’s from when they mill the rough sawn 2x4 down to “finished size”. You can buy actual 2x4s, but they won’t have the nice planned surfaces or beveled edges.
I’m not wondering why it’s that sized, I’m annoyed why they insist on calling both rough saw and finished items 2x4s.
I had to go back and re-read the history of dimensional lumber. 2x4 was an actual 2x4 cut until recommendations by the Forest Products Laboratory (American Lumber Congress?) in 1919 to balance functional and economic requirements (1 5/8 x 3 5/8). It’s neither the shrinkage nor just milling after drying, they literally just cut it smaller. And if my last 20 trips to big box stores with lumber are any indication, they don’t care about cupping or warpage either.
It’s because the actual cut is 2x4, and the wood shrinks. The typical shrinkage is known and accounted for. It is a treat when a house has an actual 2x though, i.e., it was cut divided by the shrinkage ratio, or cut dry. Related to why framing is done “on center”, i.e., “16 on center”.
That’s not from shrinkage (well the 1/16 might be, especially newer fast heated junk at the Homely Despot). It’s from when they mill the rough sawn 2x4 down to “finished size”. You can buy actual 2x4s, but they won’t have the nice planned surfaces or beveled edges.
I’m not wondering why it’s that sized, I’m annoyed why they insist on calling both rough saw and finished items 2x4s.
I had to go back and re-read the history of dimensional lumber. 2x4 was an actual 2x4 cut until recommendations by the Forest Products Laboratory (American Lumber Congress?) in 1919 to balance functional and economic requirements (1 5/8 x 3 5/8). It’s neither the shrinkage nor just milling after drying, they literally just cut it smaller. And if my last 20 trips to big box stores with lumber are any indication, they don’t care about cupping or warpage either.
You can’t convince me that wood shrinks by 35% by crossection. No way.
Yup, that was wrong.