How To Properly Tape and Fill Drywall Joints

Finishing your drywall project is probably going to be more time consuming than hanging the drywall! Joints that aren’t taped and finished properly will be very noticeable even after the walls are painted!

Before you start to do any taping, you should check all of the joints for protruding nails or screws. All of the nails and screws should be sunk just below the drywall surface.

Your first instinct may be to run your hand over the joints, but you should use a wide putty knife or other wide flat tool. Hold it as flat against the wall as you can and run it down the length of each joint watching for snags!

Before applying the drywall compound make sure that you mix it. If you’re using a pre-mixed compound just mix it slightly, over mixing can create air bubbles that will leave sink holes after it dries!

For the first coat of compound you should use a putty or taping knife that is at least 5″ wide. Holding the knife at a vertical angle, spread a generous amount over the seam making sure it fills the crack.

Once you’ve gotten the seam covered with joint compound, apply the joint tape to the center making sure that you cover the seam. Just press it lightly into the joint compound to hold it into place.

After you’ve completely covered the joint with tape, you’re ready to flatten it against the wall. Start working at the center of the joint and flatten the tape to the floor, then start at the center again and flatten it up to the ceiling.

You will need to apply a firm, even pressure when flattening the tape. This will scrape off some of the excess joint compound you applied to the joint and also help fill any cracks you might have missed.

Just make sure that you leave a layer of compound under the tape or it will eventually come loose after it dries. Never use a small knife to flatten the tape. A wide knife will flatten the tape, remove the excess compound and leave the compound under the tape in place!

While you’re flattening the tape onto the joint, clean your knife often. The thin compound on the knife will dry quickly and become hard leaving grooves in the wet joint compound!

After you’ve gotten the tape flattened, gently go back over the joint with a thin layer of compound. You want to cover the tape, but you want to be able to still see it through the layer of compound.

To tape the inside corners apply thin coats of joint compound to the seam and both sides. Cut a piece of joint tape to fit the area and then fold it in half. Using your hand just lightly press the tape into place in the corner.

Use the knife to smooth it out and remove any excess compound. Then apply a thin top coat of compound to each side, make sure that the tape is still visible through the compound.

It is best to apply thin metal covers to all of the outside corners of the drywall at doorways or windows. These will help protect the drywall from getting chipped and gouged if something bumps against them.

If you have used metal covers, you will need to fill the small ridges at the edges as you cover the corners with compound. The wide knife will extend beyond this ridge and ensure that it’s filled with the compound.

Go back over all of the nail or screw heads with another thin layer of joint compound. The joint compound covering them will shrink some after drying, so this process will need to be repeated.

After you’ve gotten all of the joints and corners taped, let the joint compound dry over night. Taping levels off all of the drywall surface, the next steps will help you get all of the surfaces smooth and ready for painting!

The fill coat takes a little more patience and you’ll be using less pressure on the joint compound. For this step you’ll need a wider knife, a blade that is from 7 - 12″ is recommended, but the wider the better.

You will need to smooth the joint compound out in three different strokes this time! Apply compound to the joint, then go down each side with the knife and then down the middle.

For the side strokes you’ll need to apply a little more pressure with the outside of the knife. You want a nice even edge while letting the inside of the knife just glide slightly over the joint.

Smooth over the center with a even pressure, this time you don’t want to be able to see the tape through the compound! This step will also help to cover up and of the holes that may have occurred when the compound shrunk over the nails and screws.

The corners and edges will need to have a second coat of joint compound in the same way. To make it much easier you can purchase a corner knife at most local hardware stores!