How to Inspect A 2 x 4 For Warp or Damage

Here's how to visually select 2 x 4 lumber. Use simple steps to determine if a two by four is warped or structurally unsound.

Difficulty: Moderately Easy

Instructions

1. View the 2x4 from end to end.
   
   Hold the narrow end of the 2x4 up to your eye. With one eye closed, sight down the length of the board. See if the board warps or bows from left to right, or if the board curves up and down.

2. Inspect the board for large knots.
   
   If the board has any large knots on the edges, it's less structurally sound. Also avoid 2x4 boards with knots larger than a quarter in the center of the beam.

3. Place the board on a smooth flat surface like a concrete floor.
   
   Place the board flat, and then up on it's side. If the board warps or curves drastically, use another board.

4. Watch out for 2x4 boards that warp or kick at the very end.
   
   Sometimes a 2x4 board looks very straight, but will suddenly kick or warp in the last two or three feet. This is especially true in a pile of boards that has been picked over, or in pile of long (over 8 ft) 2x4s.

5. Don't be overly picky.
   
   Especially in longer lengths, from 10 to 16 ft, it's very difficult to find a perfectly straight 2x4. Choose boards that don't drastically warp or bend and are structurally sound.