Final answer:
To square up a wall when framing, measure the diagonals to ensure they are equal; this confirms the wall is square. Tools like a plumb bob, level, and laser can help with vertical and horizontal alignment, but the diagonal measure is crucial for squaring.
Step-by-step explanation:
When framing and trying to square up a wall, the most common method used by framers is to measure the diagonals. This involves measuring the diagonal from one top corner to the opposite bottom corner and then doing the same for the other two corners. If the measurements are equal, the wall is square. While a plumb bob can ensure that components are vertically straight and a level can confirm that they are horizontally straight, a laser can be used for alignment, the diagonal measuring is the key method to square the frame. Measuring diagonals is similar to using a tape measure to measure the length of a room or wall. It's important to select a measuring tool that can reach across the room or wall being measured, in this case a sufficiently long tape measure.