How to tape angled drywall joints
While angled joints are far less common than standard 90 degree inside and outside corners, they do occur and you’ll need special materials and techniques to tape angled drywall joints correctly. Some examples of non-standard joints include:
- When a vertical wall meets the angled portion of a vaulted ceiling, resulting in a joint that is greater than 90 degrees.
- An inside corner where two vertical wall planes meet at a less than 90 degree angle
- A finished attic where gypsum board is attached to the underside of an angled rafter.
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How to tape angled drywall joints of more than 90 degrees
Joints greater than 90 degrees commonly occur at vaulted ceilings (a horizontal tape joint) and where angled walls meet straight walls (a vertical tape joint). You’ll often see angles of 135 degrees or even 150 degrees in this situation.
Install the drywall as you normally would, leaving gaps between panels of approximately ¼ inch.
To tape, use a flexible, composite drywall tape that is designed to be folded to whatever angle you need. The composite tape is usually sold in 100-foot rolls and it’s marked for easier measuring and cutting. Once the gypsum board is properly attached to the framing, measure and cut the composite tape to length.
Then fold the tape along the pre-made crease to fit the angled joint. Apply a coat of taping compound to both sides of the joint, and press the composite tape into the compound. This will effectively hold the tape in place while you apply additional coats of compound and smooth the seam.
At this point, return to standard taping and sanding techniques. Allow the first coat of taping compound to dry thoroughly, sand the surface smooth, and apply a second coat and possibly a third, depending on the level of finish required. Finish with a final sanding.
How to tape angled drywall joints of less than 90 degrees
Joints that are less than 90 degrees happen when walls meet at an angle of less than 90 degrees (a vertical tape joint).
Here, too, drywall as you would normally and then use composite drywall tape for the seam. Measure and cut the tape to length, fold it along the appropriate crease to fit the joint angle you are working with, apply compound to both sides of the joint, and press the tape into the compound. This will hold the tape while you apply additional coats of compound and smooth the seam. If the joint is very acute, the working space may be too narrow to use standard taping tools. You’ll need to work with a smaller joint knife to work into the joint completely and avoid damaging the gypsum board surface.
How to tape drywall joints at pitched roof
When attic spaces with pitched roofs are converted to living spaces, you will have to deal with the angle that the gypsum board that is attached to the rafters meets the floor. Typically this angle does not need to be taped, because one side of the joint is gypsum board and the other is wood subflooring. Ideally the drywall edge that meets the floor is a factory edge and the resulting joint will be small and uniform. A bead of caulk works better here than trying to tape this joint.[tip id=”5193″]