Building frames is the basic element in most construction. Your house, apartment, deck and other projects are built with many frames put together to make boxes or floors or whatever.
The first basic rule: your short end of the frame will cap your longer ends.
What do you mean?
The reason the board is 7’9″ and not 8’0″ is to compensate for the 1 1/2″ from each 4′ board on each end. In combination, they add up to 3″ and therefore subtract that 3″ from the 8’0″ boards. Therefore: 7’9″.
You want to make a perfect 4×8 frame.
Rightly so, if you are building a frame from 1x4s, you need to subtract 1 1/2″ from your shorter boards. Such as, the 4×8 frame would have 2 boards at 4’0″ and 2 boards at 7’10 1/2″.
However, it is not always the case to have your short ends cap the longer boards. In some cases, it is wiser to have your longer boards cap the shorter ones. When your longer side is expected to hold weight, the longer boards should cap the shorter boards.
The reason for this: You want the weight to push against the boards and not burden or stress the screws that are connecting your boards.
Good luck with your projects!
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