Repairing Plaster Walls

Patching plaster using ordinary drywall materials

Repairing plaster walls in older homes and buildings can be easily accomplished using ordinary drywall materials and techniques.

Common to most older homes and buildings are cracked and crumbling walls made of plaster. Given the prices that are charged nowadays to fix an old plaster wall in any given situation, whether it be a plaster ceiling repair job, or a simple skim coat plaster repair, this is a great skill to acquire.

But you don't have to be an expert craftsman for repairing plaster walls. If you can repair drywall, you can do this too.

Repairing Plaster Walls

You'll need some tools and supplies like the ones shown (picture):

carpenter's knife

putty knife

measuring tape

sandpaper

drywall repair piece

1 1/4" drywall screws

mesh drywall tape

Joint compound

drywall tools

Clear Repair Area

In the example shown below, an old hot water radiator was removed which resulted in exposing a heavily damaged wall.

Plaster Removal
Using a putty knife, begin to remove the badly damaged plaster that has begun to separate itself from the wood lathe (long thin wood strips used for support when applying plaster) nailed to the original stud.

You will notice that as you begin to dislodge loose and crumbly plaster, more and more plaster pieces begin to fall off as well. Be careful, because when repairing plaster walls, you simply want to make sure you remove only the damaged and badly separated plaster within your intended repair area. Leave those parts alone that are firmly affixed in place on the lathe.

Tip
Notice in the picture how the top is square. For all repairs, square off and even-up the sides, top and bottom of repair area. This makes for an easier cut when fitting your drywall replacement piece in place.

Set Repair Drywall Piece in Place and Apply Mesh Tape

The repair piece of drywall was cut slightly smaller than the opening so that it would fit into place nice and snug. Using 1 1/4" fine drywall screws, I fastened the piece of drywall to the lathe strips already present. If any strips are damaged, use something similar in thickness as a replacement to mount the drywall to.

Tip
I have found that using 1/4" to 3/8" drywall for plaster repair is ideal, in that it allows you to finish the seams more smoothly.

install drywall

Apply mesh tape to seams.

Tip
I have found that by adding multiple layers (overlapping the other) adds strength for the seam itself, and stability when applying mud to repair seam area.

Apply First and Second Coat of Joint Compound

After taping, apply your first coat of drywall mud to seams. When completely dry, sand smooth, and add your second coat of mud to seam area. Fan out your coverage a little farther to ensure a more even, consistent coverage. Then sand smooth.

first coat drywall mud

Prime and Paint

When you have completely sanded the repair area smooth, you're now ready to prime the entire drywall repair piece. Use a high quality primer. Not only will a good primer coat and seal the drywall, it will also ensure a nice solid base for your finish coat to adhere to.

When prime coat is dried, lightly sand to get rid of small dust particles, and apply 1 - 2 coats of finish paint to plaster repair area.

painted wall

Also ...
For light plaster wall repair of various nicks and scratches see my page on skim coat.

Anyone who has tried to remove wallpaper can attest to the damage that can be easily created, or just the simple wear and tear to wall surfaces that can happen over time in any household.

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