How to Repair Cracks in Plaster Walls

Presented by KUTV.Com.

As homes settle or wooden door and window frames dry out over time, hairline cracks can develop in plaster walls. While these cracks aren’t usually cause for great concern, they can be difficult to eliminate. Plenty of homeowners have applied spackle over such cracks, only to see the gaps reappear in no time. Therefore, the keys to treating such pesky cracks lie in the supporting the surface and thoroughly filling the open space before sanding or repainting.

Here are the items you will need to seal your cracks efficiently, some of which can probably be found in your home and others that will need to be purchased from a home improvement store:

• Joint compound or another filling product (for hairline cracks, choose a filler with average or slightly thinner weight)
• A curved knife or tool to scrape plaster from the cracks (the pointed end of a can opener can be used for this task)
• 2-inch-wide adhesive fiber mesh drywall tape
• 4-inch-wide putty knife
• Any type of cleaning cloth or shop towel
• Cotton covers or drop cloths (these are especially important if you are working with large cracks)

With your drop cloths in place and tools in hand, here is the four-step process you will need to follow to rid your walls of hairline cracks. Depending on the size and depth of your cracks, this process can take 24-48 hours as joint compound or filling agents will need ample time to dry after each application:

1. Using the pointed end of a can opener or curved knife, scrape along the length of the crack in an angled motion. The goal of this step is to widen the crack slightly and remove loose plaster, improving your ability to thoroughly fill the damaged area. After successfully widening the crack, clear out any remaining plaster or dust using a damp cloth.

2. Apply 2-inch-wide adhesive fiber mesh drywall tape along the length of the crack. If the crack zigzags along the wall, trim the tape to maintain an even application. Most importantly, don’t overlap the strips of tape bridging the crack.

3. Using a 4-inch-wide putty knife, spread a thin layer of joint compound or other filler over the tape, filling in all gaps and overlapping the surrounding plaster. Wait until your filler is completely dry – this could take 24 hours for each application depending on the product you use – and check for gaps and open spaces. If the crack isn’t completely sealed, apply another thin layer of joint compound over the tape and again wait until the surface is dry.

4. When the crack has been filled completely and the surface is dry, lightly sand the surface until you reach an even texture. Depending on the size and depth of your crack, you may also want to add one or two thin layers of joint compound during this step, feathering the edges as you go along. Once again, you must wait for the compound to dry and then sand to match the surrounding wall. After sufficient joint compound has been applied and sanding is complete, the wall is ready to be primed and painted however you like.

While this might seem like an intimidating home improvement project, especially if you need to repair several cracks, patience and follow-through will each go a long ways towards a successful repair.