Nearly every home has drywall as interior walls. Every piece is mudded and taped to seal the seams. Over time, with exposure to high humidity or water, or if the job was poorly done, the drywall tape can come loose exposing the seams. This can happen between drywall sheets as well as where the drywall meets the floor and the ceiling. Either is unsightly but can also be repaired. The article below will walk you through how to retape the drywall, but before starting, you should put on eyewear protection and a particle mask as the dust generated will be extremely fine, irritable for the eyes and nose/mouth.
Step 1 – Remove Old Drywall Tape
The old tape has to be removed prior to retaping the drywall or else you will be left with ugly bumps which give the drywall an unfinished look. Inspect the drywall for where the tape is beginning to peel or bubble from the surface. Using an extendable blade utility knife—which has more flexibility— cut along the seam of the drywall tape, and across it where it is well bonded as to not remove too much of it. Continue to use the utility knife and slide the blade under the drywall tape. This will lift it off the surface allowing you to peel it away. The likelihood of you being able to remove the tape flawlessly is slim but it is not re-usable anyway. Remove as much of the loose drywall tape as you can.
Step 2 – Removing excess plaster
With most of the tape removed, use the knife to cut down the thick and rough edges. The trick here is to flex the blade at a slight angle. Remove the old plaster down to the drywall without cutting into it too much and slightly wider than the width of the new tape. This will prevent a buildup on the new joint to make a bump when plastering it over.
Step 3 – Taping the Drywall
The choice of drywall tape is entirely up to you, but if using the paper tape, the joint has to be coated with a layer of mud first, filling the cracks as you go along. This initial coat will stick the tape to the wall. With the self-stick mesh tape, start at the top of the seam and center the tape on the joint, and unroll it the full length of the damaged strip in one piece using your hand to press the tape to the drywall and press it into the seam. This will help to create a smooth and airtight seal which leads to the drywall tape not peeling up in the future.
Step 4 – Mudding and Sanding
With the drywall tape in place, you can begin mudding. Use a trowel and apply some of the mud onto it and apply it to the wall. Use the straight edge to spread a thin layer of the mud over the tape and blending into the rest of the wall. Once the mud is on the wall you will have to wait until it dries before applying successive coats. It will require patience as you'll need to repeat several times until the surface becomes even with the rest of the wall. Certain mud will turn color when this happens to make it easy to know when it is dry. Use the sanding block to sand the drywall mud by hand until all defects and trowel marks are removed and it is flush with the wall. It may take you three or four times of mudding and sanding to get the desired effect of a flush and even wall.