- Gather the correct Tools and Materials:
- Drywall – ½” and 5/8” are the most common sizes. ½” is typically on walls and 5/8” is more common on ceilings.
- Drywall tape – Paper tape or self-adhesive mesh? Taping the seams of the repair to the existing drywall helps to strengthen the repair. Paper tape should be applied with an “All Purpose Joint Compound” (the most common version has a green lid and is USG brand) while self-adhesive mesh tape should be applied with a quick setting compound – these come in 5 or 20-minute setting times and is also manufactured by USG.
- Joint compound – the joint compound that covers the repair in the 2nd or 3rd coat is easier to sand than the setting compounds. USG makes a version with a blue lid called “Plus-3”.
- Mud pan and drywall broad knives – we recommend using 6” knives for the first coat, then 10 or 12” knives for passing over the repair in the last coats for the smoothest repair and minimal tool marks.
- Backer boards if studs are not visible.
- Drywall screws – 1-1/4” length for ½” drywall and 1-5/8” for 5/8” drywall – the screw should be about 1” longer than the thickness of your drywall.
- Utility knife or drywall saw – Both are helpful, but the razor blade will allow you to cut the backside of the drywall, snap along the cut, then cut the face-paper cleanly away. The saw will cut through the drywall completely – it may be helpful if the area you are repairing isn’t square to start with.
- Sanding sponges – these are easy to hold and work with. They make sanding the joint compound fairly easy.
- Prepare the damaged area:
- Remove damaged drywall including loose paper, cut the opening square if needed.
- Install backer boards – screw boards about 1 – 2” inches outside of repair area, make sure the drywall that you are screwing through is in good condition.
- Measure, cut and install the new drywall securely to the boards. Countersink the screws so the head is below the surface but do not push through the paper face of the drywall – the layer of paper on the top and bottom are what give drywall it’s strength.
- Apply Joint Compound and Tape:
- Apply self-adhesive mesh tape directly to the drywall. Then cover with either 5- or 20-minute setting compound. Use All Purpose compound by applying the compound first, then setting the paper tape in place. Press some, but not all compound out from underneath the paper – there needs to be enough compound to bond the paper to the drywall.
- You don’t need to sand if the first coat isn’t built up – the goal is flat coats of mud without bulges or build-up. Joint compound can be applied after the setting compound has hardened, even if it isn’t completely dry. All-purpose and each coat of joint compound need to dry completely between coats and before sanding. Depending on their thickness this can take minutes or hours.
- Apply the 2nd and 3rd coats in smooth, flat coats after each is dry. The best technique is to lay the broad knife tool almost flat to the wall while pulling it across the compound with even, light pressure. Use as many coats as needed to achieve a smooth finish. Don’t try to build up the repair in one or two thick coats – several thin coats with provide a much better finish than one or two thick coats.
- Sand the repair:
- Use the sanding sponge to lightly sand any edges and tool marks after the repair has dried completely.
- The edges of the repair should “feather” into the existing wall surface – there should not be an “edge” that can be felt when running a hand over the edge where the compound terminates into the rest of the wall. “If you can feel it you will see it.”
- Prime and Paint:
- Once the area is smooth to your satisfaction, apply one coat of primer. This can be a “self-priming” paint if that’s what the finish coat will be. The self-priming is that the first coat “seals” the repair so that the 2nd or 3rd coat of paint will have the correct “sheen” or gloss level. It doesn’t mean that you only need to apply one coat of paint.
With patience and practice, these 5 steps should help you achieve a decent repair on your walls.
