How To Repair Cracked Drywall Seams

18 May Repairing Drywall Seams, Holes and Cracks

Posted at 06:54h in Construction, DIY

Drywall seams will crack or separate for different reasons. A damaged foundation can cause it, as well as improper drywall finishing during construction. It could be that the sheetrock hanger didn't use enough screws or nails. If you have a foundation problem you should fix that before spending time on your drywall. A foundation issue is serious; it will cause your windows and doors to bind up and can cause roof problems.

When drywall is screwed or nailed to the studs, it makes for a seam every 4 feet horizontally or vertically and every 8, 10 or 12 feet in the other direction. There is also a seam in each inside corner. This makes for a lot of drywall seams and a possibility for a lot of cracking. Not to worry though, patching seams up is simple.

Drywall Tools and Materials You will Need
Preparing the Drywall

Repair the Drywall Seam
Repairing Drywall Holes
- Tools and Materials for Fixing Drywall Damage:
- Prepare the Wall or Ceiling for the Drywall Repair
- Apply the Drywall Patch
- Drywall Finishing: Tape and Float
Drywall Tape to Fix Cracks in the Wall
- Paper tape
- Fiberglass mesh tape
- Coats of joint compound

Drywall Tools and Materials You will Need

To patch drywall seams you'll need a few tools. As a minimum for tools, you'll need a taping knife, utility knife, scraper, mud pan, and possibly a ladder if your problem seam is high. You'll also need to do some sanding. It's best to use a sanding pole with sanding screens, however for fixes like this you can use regular sandpaper. Read also my article about drywall installation here.

You'll also need mud (drywall compound). Get the kind that is premixed in plastic buckets. Drywall tape is your final ingredient. Use the type that's a mesh with adhesive backing. It's easier to work with than th paper tape because of the adhesive.

Preparing the Drywall

Use the scraper to remove the texture around the seam. Starting from the seam's center go 4 inches in either direction. Scrape the cracks length and a couple of inches extra. Now, use the utility knife to cut the bad tape out where the drywall seam is damaged.

Now put some mud in your pan from the bucket. It's easier to work if its thinned out a tiny bit. Put just a small amount of water in the mud and mix it with the taping knife.

Repair the Drywall Seam

Cut a length of tape from the roll that fits the spot that is prepped (span the seam). The adhesive will keep it in place. Scoop a little bit of mud on the taping knife. Spread it onto the tape. Proceed until it's worked into the entire length of tape. You're not completely filling the void with this step. This is "taping." "Floating" will come later. Now you're adhering the tape to the joint.

Now clean the taping knife and mud pan using water while your joint dries.

When the joint is dry, sand all dried mud ridges. Now float it by spreading on sufficient mud to spread over the taped spot and leave the repair flush and level with the surrounding wall. Leave it to dry and give it a look. If it is not right, repeat. Although hanging Sheetrock is straightforward and methodical, drywall finishing is an art.

When you've got it just right, match your wall texture. Use your mud for this. Be creative; try different methods until it looks right. Dabbing the wall using a paint brush is one method. Let it dry, then sand it lightly. Experiment. Finish up by painting the drywall. You're done!

Repairing Drywall Holes

So there's a hole in the drywall. It happens. Whether the wall took a fist shot or it had a head on collision with a tricycle matters not. It's got to be fixed. Luckily, any DIYer can tackle this job. The process is just a bit more involved than repairing drywall seams.

Tools and Materials for Fixing Drywall Damage:

Utility knife
Drywall saw
Tri-square or framing square
Cordless drill with #2 screw tip
Mesh drywall tape
Taping knife
Drywall (same thickness as the existing)
Drywall compound (mud)
Mud pan
Sander with sanding screen or sandpaper
Drywall screws
Wood scrap

Prepare the Wall or Ceiling for the Drywall Repair

First, assemble the drywall tools. Use the square and pencil to draw a square or rectangle around the hole. The size of the drywall damage will determine whether to use the tri-square or framing square.
Using the drywall saw, cut out the square.
Sand off any texture surrounding the square.
Cut the scrap of wood to size; it should be four inches longer than the height of the square just cut out. Insert the scrap of wood into the hole and center it. A piece of 1" X 4" works well for this.
Hold the wood against the inside of the wall and secure it with three sheetrock screws at the top and three in the bottom. Be sure that the screw heads are slightly lower than the wall surface.

DIY Tip: If the wood is hard to hold, drill a hole through it, stick a piece of string through it, and tie a nail to it. Now it can be held tight to the wall by the string. When done, just push the string through the hole into the wall!

Apply the Drywall Patch

Cut a piece of drywall that will easily fit into the square.
Secure the drywall patch with screws. How many are needed depends on the size of the patch. Four drywall screws are sufficient for small repairs.
Apply drywall tape to all four sides of the patch. Next, taping and floating.

Drywall Finishing: Tape and Float

Put some drywall compound in the mud pan and use the taping knife to thin the mud just a tiny bit with water.
Now use the taping knife to spread mud on the tape and on the screw indentations. Use the knife to smooth it out but don't leave a thick coat. This step is just to fill the joints and secure the tape.
Let the mud dry.
Sand any ridges on the dry drywall mud.
Now comes the floating step. Once again, get some mud in the pan and apply it to the patch and a few inches beyond the tape. The goal here is to have the wall surface flush and even.
Let the mud dry and sand it lightly, feathering the outside edges to blend in with the surface.
Admire the patch! Is it good? Satisfactory? If not, float, dry, and sand again.
Match the drywall texture, paint with primer, match the paint color, and paint.

Job well done!

Drywall Tape to Fix Cracks in the Wall

One of the most common places for drywall cracks is at the seams. Cracks happen because of the house shifting over time and excessive moisture changes between seasons. While the type of joint compound makes a difference in the durability of the drywall seams, the type of tape used is the first line of defense to preventing drywall cracks.

Paper tape

The surface of the drywall has joint compound applied to the seam and then the tape is laid on top of the joint compound. A thin layer of joint compound is then troweled over the tape completely adhering the tape to the drywall seam while removing air bubbles from behind the drywall tape. While this type of tape joint works just fine for most applications, it is not as durable on horizontal applications. However, there is no better solution than paper tape for inside corners than paper drywall tape.

Fiberglass mesh tape

Fiberglass mesh tape is made of a self-adhering strong mesh that is woven fiberglass strands rolled into a tape. Instead of using mud to fill the voids initially, the tape is simply applied right to the drywall and sticks to the drywall. The joint compound is then spread over the mesh tape. Once the joint compound is dry, the mesh tape forms a much stronger seam than paper tape so that when shifting occurs, cracking is much less likely.

Coats of joint compound

Most professional drywall and plaster experts use 2 to 4 coats of joint compound in order to create a seemingly smooth surface. The extra layers of joint compound also add to the strength of the joint. As mentioned before, the type of joint compound used also helps prevent cracking at the seams. A heavy joint compound is a good starter coat, while lightweight joint compound is good for the final coat or two.