Floating drywall corners is the process of covering drywall seams on the corners with tape and a thin layer of mud.
Most people usually assume that they will be dealing with only flat seams when installing drywall. However, in every drywall project, you will have corners that need to be taped and mudded to create a perfect finish.
Today, I will be taking you through the steps on how to float drywall corners. Please note that there are two types of drywall corners; inside and outside corners.
I will discuss both so that you can have sufficient knowledge on how to finish either type.
How to Float Inside Drywall Corners?
An inside drywall corner is the most common type. It refers to the corners in a square room where two walls meet to form an internal angle.
The ugly truth is that floating inside drywall corners isn’t easy. That’s because you are working on three corners; the intersection between two adjoining walls and the ceiling.
This process needs practice for you to perfect your skills. But it’s doable.
Step 1: Gather Essential Materials
You will need paper tape, a pole sander, a trowel or drywall knife, 150-grit sandpaper, and enough drywall joint compound. You should also get a mask to protect you from the dust that comes from sanding.
Step 2: Clean the Inside Corner
If construction is still ongoing, then there is a huge chance that the corner is dusty. To ensure maximum adhesion between the seam and the joint compound, dust off the surface thoroughly.
Step 3: Bed Tape the Corners
Because paper tape doesn’t have an adhesive, you should start by applying bed tape over the corner. If it were mesh tape, you could have installed it first.
Using your drywall knife, run some joint compound on the inside corner. It should be around 1/8 inch thick.
Step 4: Fold the Tape and Run It from the Top to the Bottom of the Inside Corner
Earlier, I mentioned that you should use paper tape when floating an inside corner. If you are wondering why, it’s because the paper tape is much stronger and easier to work with than mesh tape. Also, with paper tape, you can easily crease it at the center.
Therefore, fold your paper tape into two halves. Lay it on the top of the corner and run it down. It’s imperative that the paper is pulled tightly and pressed firmly into the bed coat.
This ensures maximum adhesion. A pro tip you can follow when taping an inside corner is to cut the tape at an angle so that it perfectly fits the joint at the ceiling. This is better than having excess tape extend to the ceiling.
Step 5: Apply Some Drywall Compound Over the Tape
Using your drywall knife, apply a light amount of compound over the tape. You need to use minimal pressure, as this will prevent you from tearing the paper tape. Don’t forget to also apply drywall compound in the corners where the tape meets the ceiling.
Step 6: Apply the First Coat of Drywall Compound
On the next day, apply the first coat of drywall compound on both corners. You need to make sure that the coats on either side of the corner do not overlap one another.
If you were using hot mud, you need not wait for the next day. You can start finishing in an hour or two. But if you are using regular drywall compound, you need to wait at least 24 hours before applying a finish coat.
Step 7: Apply a Second Finish Coat the Next Day
Wait another 24 hours before going in with a second coat of drywall compound. Avoid being generous with the coats as this can cause a buildup of mud on the inside corner. Be very keen when feathering.
Step 8: Sand Bumps and Rough Spots
Even professionals get rough spots after floating drywall inside corners. This is why sanding is the last and most important step.
Using a pole sander and 150-grit sandpaper, smoothen out any bumps or rough spots. This should create a smooth finish on your corners.
How to Float Outside Drywall Corners?
An outside drywall corner is where two walls meet to project an outward space. Though not as common as inside corners, they are sometimes unavoidable and that’s why you need to learn how to float them correctly.
Step 1: Gather Materials
You will need materials that are a bit similar to the ones used to float an inside drywall corner. Examples include a joint compound, a drywall knife, a machine sander, and 150-grit sandpaper.
However, you will also need a corner bead because of the design of this seam and a special drywall corner tape.
Step 2: Start by Fitting the Bead to the Outside Corner
Unlike in an inside corner, when floating an outside drywall corner, you need to reinforce the structure with a corner bead. Tape and mud won’t be enough to create a solid and durable finish. This is why a corner bead is necessary.
Measure and cut your corner bead to match the length of the outside corner. Secure the corner bead to the drywall by using screws.
Step 3: Apply the Drywall Corner Tape
Grab your special corner tape and apply it over the seam. Make sure that the tape touches both sides of the corner and that the corner bead is fully covered. The tape should run from the top to the bottom.
Step 4: Prepare Your Drywall Mud
Using the instructions provided by the manufacturer, mix drywall with water and additives. Mix it up until you get a paste consistency.
Step 5: Apply and Spread the Mud Over the Outside Drywall Corner
Using a drywall knife, preferably an 8-inch, apply drywall mud over the tape. The mud should be about a quarter inch thick.
The thinner the mud, the more you avoid buildup. Smoothen the mud using the knife and feather it out towards the outside. Make sure that you press on areas where bubbles have formed.
Step 6: Sand the Mud Once It Dries
Because impurities are unavoidable, you should sand the mud after it dries. The sanding should be light to avoid tearing into the paper and corner bead.
Step 7: Finish the Outside Corner with Two Coats
On the next day, apply another light coat while feathering the edges. Give it 24 hours before applying the second and final coat. Once it cures, you will have successfully floated your outside drywall corners.
How to Avoid Buildup When Floating Drywall Corners?
When floating drywall corners, especially inside corners, it’s very easy for mud buildup to occur. The good news, however, is that this can be avoided through sanding and applying thin coats of joint compound.
You should also know that drywall edges are slightly thinner which creates enough room for several coats of joint compound.
Unless you are applying very thick layers of mud or using two tapes in one corner, you don’t have to worry about mud buildup on corner seams.
What’s the Importance of Correctly Floating Drywall Corners?
Contrary to popular belief, the process of floating drywall corners doesn’t only beautify your interiors. It also makes your walls more stable.
When the seams are left bare, your corners will be more vulnerable to damage and they will have a shorter lifespan. You need to float drywall corners once you are done working on the flat seams.
And if this process seems a bit complex or time-consuming, you can always seek the help of a professional drywaller.