A.Myron Ferguson, a
drywall contractor in Broadalbin, N.Y., and the
author of Drywall: Professional Techniques for
Walls and Ceilings, responds: I'm not a framer, but
the first thing I look at when I'm hanging drywall
in these very conspicuous corners is the framing.
If it's off, I first do a little shimming or
floating over high spots along the edge. After
hanging the drywall, it's sometimes necessary to
prefill low areas with joint compound so that the
seam is reasonably straight.
To tape the joint, I like to use a continuous
piece of 31/2- to 4-inch-wide paper tape, since I
may have to conceal some gaps in the drywall and
adjust the tape to get a straight line. Because I
apply compound to both edges simultaneously, I like
to work with a helper on longer walls, so that the
compound doesn't start to dry before the tape is
embedded.
After pressing the tape into place —
but before it is embedded — I sight down
along the corner as my helper makes adjustments to
straighten the tape.
Finally, after embedding each edge, I sight down
it yet again, making minor adjustments as necessary
(marking the center of the tape first with a pencil
line helps make the sighting easier).
Several brands, such as No-Coat (Drywall Systems
International, 888/662-6281, www.no-coat.com) and
Strait-Flex (Strait-Flex International,
888/747-0220, www.straitflex.com) now offer special
tapes that can be used on these difficult,
off-angle inside corners. An interesting product I
use a lot is Magic Corner (Trim-Tex, 800/874-2333,
www.trim-tex.com). Made of vinyl with a rubber
center, it's adjustable and easy to get straight,
and it also acts as an expansion joint.
With all of these products, applying compound
along the center isn't necessary — and
with Magic Corner it's not recommended. As long as
the tape is applied straight, it will finish
straight, because only the edges are feathered in
with joint compound.
Another good option I've used is Strait-Flex's
X-Crack, an adjustable metal angle that attaches to
the framing along the corner before the drywall is
hung. The drywall is attached to the metal only
along the corner, resulting in a straight corner
that floats off the framing, so it's resistant to
cracking.
By the way, some people recommend just scoring
and folding — but not snapping —
the drywall so that the two halves of the sheet
bridge the angle. This technique, which doesn't
require any taping if done right, can work okay on
short walls, but it's not very strong. If the
framing isn't perfect, the drywall paper will tear
or separate as the board is fastened near the
angle. It's also difficult to position a larger
piece of drywall without tearing the joint.