It's important to correctly install the drywall in a corner shower. Correctly installed drywall will reduce the chance of drafts seeping into the room, cooling the air and increasing condensation behind the walls. Condensation causes mold and mildew growth. Properly finishing drywall in a corner shower will also guarantee an even surface which will make installation of the stall easier. Follow these steps to finish the drywall in a corner shower.
Step 1 - Prepare the Drywall Tape
Use a sharp utility knife and a straight edge to squarely cut the tape to the length required for the corners. By this time you should have filled the holes on the flat surfaces of the drywall and sanded them so all that's required is to finish the corners. Cut the length of the paper a slightly longer than what's needed. Carefully fold the entire piece in half to create a crisp center crease. Try not to wrinkle the paper. Lay the paper to the side.
Step 2 - Apply Mud to the Corner
Partially fill a mud pan with ready-mixed joint compound. Don't use setting joint compound; it will harden too quickly. Use the joint knife to smear the compound along the length of the corner on both walls. Apply it as evenly as possible.
Step 3 - Set the Tape
Position the drywall tape into the corner beginning at the top and gently moving to the bottom. The crease should fit perfectly into the corner. Even slightly rounded corners will make it difficult to fit the stall flush against the wall. Press the paper to the compound with firm, even pressure.
Step 4 - Skim the Mud
Hold the joint knife at a 30-degree angle. With press down along the compound beginning at the top and moving to the bottom. Doing so will remove any extra mud. If too much mud collects on the blade, scrape the knife in the mud pan to remove the compound.
Skim again, but press slightly harder the second time. It's important to remove all the extra mud from under the tape so that it doesn't pop off over time. Be careful not to press too hard, or you'll tear the paper.
Step 5 - Apply the Final Coats of Mud
Allow the first coat to dry for several hours. Apply a second coat of mud and skim. Wait several hours, then apply and skim the final coat of compound. Once it is completely dry, use some mud on your finger to smooth the crease. Allow it to dry. Sand the corner. Apply water resistant primer.