Applying Plaster to Drywall

guys on stairs

Can you apply plaster to common drywall, or does the application of plaster require special backing such as Wonderboard?

— Thomas, Louisville, Kentucky


Steve Thomas replies: Wonderboard is actually a trade name for cementitious backer board, which is cement and vermiculite that's cast into sheets. It is usually used as a backing for tile, but not for veneer plaster. Veneer plaster requires a substrate of what's called blueboard, which is regular drywall with a waterproof coating (which happens to be blue). If you have drywall up presently, and you want that veneer plaster look,
then I would skim the surface of the wall with drywall compound, which
goes on quite easily. Use a broad knife to apply a thin coating. You can
then sand it lightly, and you will get a surface that will approach that
of veneer plaster. But you cannot use veneer plaster on regular drywall.
It must be put over blueboard.


TV Listings

Find TV Listing for This Old House and Ask This Old House in your area.