Fibreglass mesh tape is used to repair cracks in walls and ceilings because it is more flexible than paper tape and it makes repairs stronger. Fibreglass mesh tape is resistant to blistering, does not stretch as easily as paper tape and fibreglass mesh tape does not need to be embedded into drywall compound. Fibreglass mesh tape is also tacky on one side, which eliminates having to apply joint compound prior to taping the crack. You can purchase mesh tape in rolls measuring about 2 inches wide by 75 feet.
Remove any loose drywall in the crack or hole. If you are repairing a small hole, score lightly around the hole with a utility knife just outside the edge of any loose paper. Remove the loose paper inside the scored area. Scoring prevents the paper from tearing, which would make your repair more difficult.
Cut a length of fibreglass mesh tape with a utility knife to be 1 to 2 inches longer than the area to be repaired. Center the length of tape over the crack. If the crack is wider than the tape, apply another strip, butting the edges of tape together. Do not overlap the edges of the tape because overlapping will make a ridge that will be difficult to hide. Smooth the tape with your fingers to make sure it is secure.
Apply a thin coat of joint compound over the mesh tape using a wide putty knife. Make sure you cover the tape. Apply the joint compound as smoothly as possible around the edges. Using too much joint compound may cause it to crack while drying. Allow the first coat of compound to dry according to the manufacturer’s instructions.
Apply a second thin coat of joint compound over the first. Again, try to make it as smooth as possible. Allow the second coat to dry. Once the second coat is dry, apply one more coat of joint compound and allow it to dry.
Sand your repair lightly with a sanding block. Sand just until smooth. Use a white rag to remove any residue. A coloured rag may stain your new repair.
Prime and paint your repair.
If the edges of your repair are rough, you can use a slightly damp sponge to smooth them.
Wear a face mask if you are making several repairs that require sanding.