Plumb Bob Plumb Bob
A plumb bob is a weight that when hung from a string and allowed to remain still, will designate a perfectly vertical line. A plumb bob is used in construction, particularly when framing walls, as you want your walls to be perfectly vertical.
The plumb bob uses the law of gravity to find plumb or exact vertical. Think of it this way, if a level is used to find horizontal level, a plumb bob is used to find exact vertical. It is not surprising that the plumb bob has been in use for centuries. It is believed that the Egyptians used them when building the pyramids. As for finding level, it is thought they flooded ditches to find level. Ingenious and industrious.
How To Use a Plumb Bob
• Affix a line or string (not stretchy) to the plumb bob.
• Attach the string to the top point to be plumbed.
• Leave enough room for the plumb bob to swing freely.
• When the weight stops moving, the point is exactly below the place where the string is attached above.
Carpenters and builders commonly use a plumb bob when framing walls and when hanging doors. Just as you need your floors level, you do not want your walls to lean, and doors that are not plumb will not be able to open and close properly.