While it’s most common to sand plaster dry, it is possible to wet-sand plaster, too. Doing so can reduce the amount of plaster dust released into the air and make it easier to work in smaller, more delicate areas (such as around wall trim). However, some people find that wet sanding leads to more imperfections, which is why larger walls are more often dry sanded to ensure an even finish.
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.
You’ll want to inspect your plaster walls for signs of damage before painting. If you notice soft spots, deep cracks, bubbling, or areas where the plaster is crumbling or pulling away from the wall, it likely needs repair. While small hairline cracks are common and likely cosmetic, you should address larger issues before painting to ensure a quality, smooth finish.
It is possible to apply plaster on the interior or exterior of your home, but we don’t recommend it. Plaster is easy to apply in theory, but in reality, it can be a challenging material to work with, and it’s difficult to get the finished product to look clean, even, and smooth. Many DIYers end up calling in a professional afterward to touch up the area or even redo it entirely because of mistakes they made in the process. Hiring a plaster pro will cost more, but it’s usually the best option to achieve high-quality results.
Plaster ceilings can sag for several reasons. In some cases, the plaster and other building materials shift and come apart over time, which is why you’ll commonly find drooping plaster ceilings in older homes. Improper installation, foot traffic, and water damage—often from a leaky roof or a broken pipe—can also cause plaster ceilings to sag.
The Indio, CA homeowners’ guide to plaster repairs
From average costs to expert advice, get all the answers you need to get your job done.
Venetian plaster can add depth and texture to your aesthetic. Learn how much Venetian plaster costs based on factors like square footage and whether you hire a pro to help.
You can find plaster walls in a lot of older homes. What’s behind these walls—whether that’s lath or calcimine—can have an impact on how long they last. Finding out the age of your house can help you determine what you’re dealing with.
Who does plaster work? A plasterer, of course—one who’s gone through years of training to master this subtle construction art. Here’s what you need to know.