Get matched with top drywall pros in Apple Valley, MN

You can put certain types of plaster over other types, but doing so isn't always the best idea. For example, putting a coat of gypsum over lime plaster is possible, but doing so will limit the lime plaster's breathability and potentially affect its performance.

Since cement plaster tends to leave a textured surface, no matter how much you smooth it, some people prefer to use gypsum plaster as a topcoat over cement plaster, creating a smoother surface.

You can usually tell if you have plaster or drywall by touch (plaster is harder, colder, and smoother than drywall) or by tapping on it (drywall sounds hollow, plaster does not). If you still cannot tell, peek under an outlet cover and check the cut edges. The rough edges show the composition of the wall. You will see either drywall (two paper sheets sandwiching gypsum material) or only plaster material (no paper sheets).

All plaster walls will crack over time due to normal house settling and expansion and contraction from temperature and moisture changes. Small, thin hairline cracks are generally not serious and are mostly a cosmetic issue. However, larger or more significant cracks can indicate structural problems.

Here's how to tell the difference:

• Cosmetic Cracks: Cracks that are 0.5 cm (0.2 inches) or thinner are typically cosmetic.

• Structural Cracks: Cracks wider than 0.5 cm, excessive or deep cracks, multiple cracks in the same area, or cracks that span around corners can signify a structural or foundation issue. Cracks along the joints where walls meet the ceiling also warrant attention.

For cracks wider than 0.5 cm, structural repair is needed. If a crack is 2.5 cm (1 inch) or wider, or if you notice any signs of a structural problem, it is best to contact a plaster repair professional to assess the damage.

If you already have plaster walls and ceilings, adding new plaster costs $2 to $10 per square foot. For an average-sized room, that would come out to $1,200 to $10,000. However, the cost to replace plaster with drywall is higher—running between $720 and $1,250 for a 10-by-8-foot wall or ceiling (not including drywall finishing).