Deciding whether to repair or replace drywall can be tricky, but your top considerations should be the extent of the damage and what caused the damage. For instance, if you need to repair a small hole caused by a doorknob that hit the wall, you can safely patch it without a second thought. However, if you have significant drywall damage caused by water damage, it’s best to thoroughly remove the drywall to inspect and repair the pipes behind it before replacing it.

Costs depend on labor, material quality, wall preparation, and finishing requirements.

A nail in drywall cannot hold very much—usually only a few pounds. A nail in a stud can add support and hold around 20 pounds. If you are trying to hang something heavier, get some help from drywall anchors—toggle bolts are very strong and able to withstand more weight.

This depends on how much plaster is applied and in how many layers, but a decent estimate is around 150 square feet. If you are applying only two coats on a small wall, there is a chance you may only need one or two gallons for the entire project. If you are plastering a large living room wall with high ceilings, using one of the more involved techniques–like Scagliola–that requires several coats, expect the project materials costs to add up quickly.