How to Repair Drywall Cracks

Step by Step Instructions on Repairing Drywall Cracks

By Mark J. Donovan

Repairing drywall cracks is easy to do. To repair drywall cracks you will need a 6” taping knife, a 10” taping knife, a utility knife, and some joint compound and drywall tape.

Drywall cracks can occur for several reasons. Sometimes drywall cracks form due to improper taping and mudding. Other times they form due to an insufficient amount of drywall nails and screws being used when hanging the drywall. Other times drywall cracks form simply due to the house settling.

Depending upon how bad the drywall cracks are, there are two methods of drywall repair.

If the drywall tape is literally cracking and pealing then a more extensive effort is required. If you simply see some hairline cracks then the drywall repair job is a little easier.

Minor Crack Drywall Repair

To repair small hairline cracks or bulges in the drywall, rough up the crack area with 100 grit sandpaper to create a textured surface. This will provide a good bonding surface for applying additional joint compound.

After roughing up the surface use a rag to dust off the crack or seam.

Next, use your 10″ wide drywall knife and apply a coat of joint compound over the drywall crack or seam. Make sure to apply a slightly heavier amount at the midpoint of the crack or seam and flare the joint compound out at the edges. Allow the coat of joint compound to full dry.

After the first coat has fully dried, apply a second skim coat layer of joint compound over the seam and flare it out even further to approximately 10-12 inches in width.

After the second coat has fully dried, sand the edges smooth with drywall sanding screen or sandpaper to blend the seams into the surrounding drywall surfaces. Wipe the dust off the wall using a rag and then vacuum the area.

Finally apply a coat of primer, and then paint the walls.

Repair Drywall with Failing Tape

To repair drywall with failing taped seams it is best to simply peel the drywall tape from the seam. To do this, use a utility knife to score the edges of the drywall tape just beyond the length of the bad tape.

Next, slice down the middle of the taped seam with the utility knife and then peel the tape off the wall.

After removing the drywall tape, use sand paper to rough up the surface area.

Next, using a 6” drywall taping knife, apply a thin coat of joint compound over the seam and then imbed new drywall tape into the mud. After imbedding the tape into the joint compound apply a thin layer of joint compound over the tape and allow it to fully dry.

As an alternative to the paper drywall tape you can use fiberglass mesh tape. Fiberglass mesh tape has a sticky surface so you can place it directly over the drywall crack or seam without needing to first apply a thin layer of joint compound.

Once the first coat of joint compound has dried, use your 6 inch taping knife to knock off any high spots on the first coat of joint compound.

Next, use a 10 inch drywall knife and apply a second coat over the first layer. Make sure to flare out the seams to approximately 6 inches wide.

After the second coat has thoroughly dried, apply a final skim coat layer using the 10 inch drywall knife. Again, flare out the seams a little more, to approximately 10-12 inches in width

Once the skim coat layer has dried gently sand the crack or seam using drywall sanding screen to blend in the edges into the surrounding drywall area. Do not over sand the seam and be extra careful over the actual drywall tape.

How to Repair a Large Drywall Hole EBook

Wipe down the wall and vacuum up the dust and apply a coat of primer over the repaired drywall crack or seam.

Finally paint the area and you have completed the drywall repair.

For information on repairing a large drywall hole, see the “How to Repair a Large Drywall Hole” Ebook from  The “How to Repair a Large Drywall Hole” Ebook provides step-by-step instructions on how to repair your damaged wall so that it looks as good as new.

See’s Drywall Calculator

Related Information

Additional Drywall Installation Resources from

Free Home Addition Price Quotes with No Obligation!

Fill out our 3-5 minute quick and easy form, and receive a free price quote on a house addition from one of our prescreened and licensed home addition contractors. This process is free and there is no obligation to continue once you receive your house addition price estimate.