How to Tape Drywall with Fiberglass Tape

Lead Image for How to Tape Drywall with Fiberglass Tape
  • 8-12 hours
  • Beginner
  • 100-1,500
What You'll Need
Fiberglass drywall tape
Joint compound (setting)
100-grit sandpaper
12-inch drywall knife
Plastic straight edge

When hanging drywall, you are left with seams that need to be sealed, and tape is used to cover these joints. If you do not cover the drywall joints, the mudding and painting of the drywall will not come out looking good. There are several products you can use to seal the drywall, but none are as good or as effective as fiberglass tape. Other tapes used to seal drywall joints require mudding in order for it to stick to the drywall. Fiberglass tape is self-adhesive, which makes it easier to work with, and it takes less time to apply. The article that follows will show you how to use fiberglass tape to properly seal drywall joints.

Place the Fiberglass Tape

Fiberglass tape does not require any mudding of the drywall joint before taping, which does save you a lot time and effort. The adhesive on the back of fiberglass tape makes it easy to put on the drywall. Take one end of the fiberglass tape and carefully center it over the seam, and make sure the top is covered. Press down on the fiberglass tape to affix it to the drywall. Draw the tape away from the wall while gently pushing down on the fiberglass tape to stick it to the drywall. The tape should run the entire length of the seam. Once you reach the end, use a pair of scissors to remove the excess fiberglass tape. Do not use the fiberglass tape on walls at an angle. The fiberglass tape will most likely break, so use other taping solutions for this part.

Smoothing it Out

Once the fiberglass tape is on the drywall, it may not be perfect. Unlike paper tape, which requires mudding to adhere to the drywall, you cannot remove and adjust the fiberglass tape. The self-adhesive backing of the fiberglass tape is potentially the downfall if you make a mistake putting it on the drywall. To help matters you can run a finger down the center of the fiberglass tape. This will push the tape into the joint. Use a plastic straight edge, and with even pressure, slide it from the top of the fiberglass tape to the bottom. This will flatten the tape as it pushes out any air bubbles that may be present.

Joint Compound

The setting joint compound is used to make sure everything stays where it is supposed to. Use the drywall knife and put a little compound on the end of it. Start at the top of the drywall and spread the compound downward. Add as much compound as you need in order to cover the entire seam. It may take several passes. Try to feather the edges out to minimize the sanding you will have to do later on. Once the joint compound has fully dried, you will need to sand it down until it is smooth and even with the drywall.