Like most liquids, if you store paint in areas prone to freezing temperatures, such as a garage or shed, the paint will freeze. If this happens, often the paint is ruined and cannot be reused. However, in other cases, frozen paint may be restored and used if you take the proper measures to unthaw it. Before discarding frozen paint, try once to see if it can be restored back to its original consistency.
Place newspaper on a countertop or table to protect the surface.
Move the frozen paint indoors. Set the can on the newspaper. Allow the paint to thaw at room temperature overnight.
Remove the lid to the paint can and check the thawing process. Push a paint stirrer into the paint. If it is difficult to do so, the paint needs to be thawed longer.
Stir the thawed paint with a paint stirrer. If the paint is clumpy and/or has a smell unlike regular paint, do not use it--it won't stick or cure properly. If the paint has a normal, smooth consistency, you can use as you normally would.
Dispose of ruined leftover paint according to your local household hazardous material laws. For latex paint, the most commonly used household paint, this usually involves allowing the paint to fully dry out and then discarding with your normal household waste. Oil paint normally must be taken to a household hazardous waste facility.