How to Repair Plaster Walls in Old Houses

Install a 3/16-inch masonry drill bit into a a drill and put on safety glasses.

Place the drill bit against the plaster wall appropriately 1 to 1 1/2 inches to one side of the crack or chip. Squeeze the trigger and drill down until you feel resistance, which means you have hit the wooden lathe behind the wall. If you go all the way through the wall, remove the drill bit and try another location.

Move the drill bit 3 inches down or up from the first hole, which is where the next piece of lath is located. Create another identical hole. Continue this process to create holes along both sides of the crack.

Insert a crevice attachment on the end of a vacuum hose and turn the vacuum on. Hold the end of the tool up to the plaster wall and hover over each of the holes to suck out any plaster dust that may interfere with the repair process.

Twist open the nozzle of a liquid conditioning product specifically made for plaster repair. Place the nozzle up to one of the holes and squeeze the trigger twice. Repeat the process for each additional hole.

Insert a plaster repair adhesive tube into a caulk gun and then insert the tip into one of the holes. Run a utility knife gently over the tip where it emerges from the wall. Pull the tip out of the wall and cut the entire tip off at the scored location using the utility knife.

Place the tip back into one of the holes and squeeze the trigger of the caulk gun until adhesive appears at the opening of the hole. Wipe away any excess from the surface of the wall with a rag.

Insert a drywall screw though a round plastic washer and then place the tip of the screw into the center of the crack or chip. Insert the screw with a screwdriver until it is flush with the wall. Insert additional screws every 6 inches along the damaged area.

Allow the adhesive to dry for the amount of time indicated on the tube and then remove each of the drywall screws by turning them counter-clockwise with a screwdriver.

Scrape off the surface of the wall with a putty knife to remove excess dried adhesive. Use a wide drywall knife to apply joint compound over the entire surface of the plaster wall until the crack, chips and all holes are completely disguised.

Allow the joint compound to dry overnight and then apply a second coat. Allow the second coat to dry overnight and sand lightly with a fine-grit sandpaper, followed by the paint color of your choice.