Use the caulk gun to squeeze up to one handle-pull of adhesive into each hole (right). Spray the conditioner from the adhesive plaster repair kit into each hole and on any exposed lath (left) it will soak into plaster and lath, preparing them to bond to the adhesive.
You now should have clear access to the space between the plaster and lath. (Most lath is 1¼” wide, spaced ¼” apart, and laid horizontally on walls.) If there are existing damage holes extending down to the lath, drill 3/16″ holes 1½” away from the edge of the hole, around the perimeter-one in every lath. Plastic washers and drywall screws, for clampingĪlong the crack’s length, drill 3/16″ holes on both sides, about 1½” apart, in every other lath.Disposable drop cloths and plastic sheeting to protect adjacent surfaces.Ready-mix joint compound for filling drill holes and cracks, and topping patches (available at many good hardware and building supply stores).Patching plaster to use in deep holes that extend down to the lath (Look for one specifically made for repairing old plaster.).Feeling a little jump as the bit drills through the plaster, before it hits the lath, signifies a gap between the two and means the plaster needs to be reattached. You also can drill a 3/16″ hole through the plaster to the lath. Any movement felt under your thumb is a sign the plaster needs reinforcing. On cracks, place one thumb on the crack, and use your other hand to alternate pressing on one side of the crack and then the other. Press on the plaster to see if it’s loose. In a well-maintained home, your plaster walls and ceilings should last forever. Fix the structural issues, and any surface treatment will last.Īll plaster failure starts as small cracks, actual holes, or missing keys. By reattaching the plaster to the lath, you’re using the lath to bridge and stabilize the plaster. Repairing loose plaster is straightforward, and consists of two distinct tasks: reinforcement and cosmetic surface applications. Today, you don’t need to know how to apply three-coat plaster to repair cracks and holes. Of all the problems affecting plaster, separation and cracking from the lath is the most common. (Gypsum was later added to the mix.) Properly installed, plaster is squeezed through spaces between the lath to form “keys” (a kind of hook) that help keep it in place. Plaster-common in old houses built between 17-is usually a mixture of lime putty, sand, and animal hair applied over wood lath.