Fixing Cracked Walls Permanently

                                        Fixing a cracked wall is an easy do-it-yourself project

Whether found in drywall, plaster or concrete, a crack in a wall is an eyesore. Generally caused by the natural settling of a house over time, you can repair a cracked wall in a weekend. Simple tools and materials from your local home improvement store will have you on your way to a smooth wall. Take note, though; if drywall cracking or surface distortion is severe or there are other indications of significant settling or potential structural problems, have your home inspected by a qualified building professional before repairing the drywall.

Fixing Drywall:

Fixing a crack in drywall is the easiest of the three wall types you are likely to encounter in your home. Use a utility knife to cut a 1/8 inch to 1/4 inch V-notch along the length of the crack. Vacuum out loose material. Cover the crack with either mesh joint tape or joint compound and paper tape, followed by a thin layer of joint compound, extending about 2 inches on each side of the tape. Allow to dry. Apply a second coat of joint compound, feathered approximately 6 to 7 inches on either side of the crack. Allow to dry overnight. Lightly sand until smooth. The wall is ready for paint or wallpaper. 

Plaster Wall Patching:

Treat minor cracks in plaster similar to a drywall crack, with joint compound. However, if the plaster is pulling away from the lath, you first need to shore up the wall with a two-step process that includes a conditioner spray followed by adhesive. Start by drilling holes with a 3/16-inch masonry bit that will penetrate the plaster but not the wood lath, every three inches along the length of the crack. Vacuum the dust and debris from the holes. Spray the adhesive conditioner into each hole. Allow dwell time as per the manufacturer's instructions. Inject the adhesive into each hole, beginning at the lowest point of the wall. Clean up excess adhesive with a damp sponge. Immediately attach plaster rings with a drill to pull the plaster tight against the wall. Allow to cure as per the manufacturer's instructions. Remove the plaster rings. Hide the holes and original crack with a coat of joint compound. Lightly sand, then apply a second coat of joint compound. Sand smooth when dry.

Concrete Walls:

To repair a concrete wall you will need an epoxy repair kit. The epoxy will make a watertight seal in the crack. Begin your repair by tapping 3-inch finish nails partially into the crack every 12 inches; these nails will attach injection ports. Epoxy comes in two parts, A and B, which you need to mix just before using. Mix equal parts of the epoxy on a scrap piece of wood with a putty knife. Apply a small amount of mixed epoxy on each injection port tab; attach each port against the wall by covering each of the finish nails with one port. Spread mixed epoxy over the crack, extending 1 inch on either side of the crack. Cover the flange of each injection port with epoxy as well. You can use a paintbrush dipped in mineral spirits to feather the epoxy at the edges. Allow to cure for six to 10 hours. Using a caulk gun, inject liquid concrete repair into the ports, starting at the bottom, until the liquid oozes from the port. Plug each port before moving to the next. Allow to cure for at least five days, then cut the port flush with the wall with a hacksaw.

Repairing Deep Cracks:

If cracks in drywall or plaster are deeper than a 1/4 inch, you will have better success if you first fill the crevice with a filler compound prior to taping with joint compound. Mix the compound as per the manufacturer's instructions. Fill the crack until it is flush with the existing wall. Cover with tape and joint compound, as outlined previously, to achieve a smooth wall.

Signs of Structural Damage:

Concrete walls, especially in a foundation, are load-bearing walls. Although you can patch minor cracks, major fissures can be a sign of poor structural integrity. A horizontal crack that stretches the length of a wall as well as bulging is a tell-tale sign of serious damage. Cracks of this nature should be repaired only by a professional.