Though they're a pain, drywall butt joints are a fact of life
for most contractors. Avoiding them altogether is best, but
there are few jobs where that's possible — and on the
smaller remodeling projects I do, they're commonplace.
Usually, butt joints — where the non-factory-tapered
edges of two boards meet — land over a stud or joist that
both edges get screwed into. The main problem is that the
framing is seldom flat. More often than not, the stud or joist
is bowed and creates a hump that accentuates the joint. Also,
on new construction, the framing is likely to shrink, cracking
the joint. The final aggravation is that finishing a typical
butt joint requires feathering the mud out by as much as a foot
or more on either side, to hide the hump that the joint itself
creates in the wall or ceiling.
So let's just say I was happy to discover an amazing new tool
— the ButtTaper (www.butttaper.com) — that creates a
joint that's as flat as a factory-tapered joint and remarkably
easy to finish. Made of aluminum, it allows the user to create
a taper on any section of drywall.
To use this tool, you have to treat the butt joint differently
during the hanging process. Here's how I handle a typical
remodeling job, where new drywall has to be blended into
First, I cut back the existing joint (1) so that the new edge
lands in the middle of the joist bay (2). Next, I screw a
4-inch-wide rip of 1/2-inch or 3/4-inch OSB or plywood to the
back of the existing piece for the length of the joint (3),
then overlap the second sheet onto the OSB backer and screw it
in place (4).
After that I wet or moisten the joint (5). The ButtTaper comes
with a small pump-type spray bottle, but you can also wet the
drywall with thinned joint compound. The wetter you make the
edge, the easier it is to create the taper on the boards
— but you still don't need much water, which is nice if
you happen to be working over a finished floor.
Once the joint is wet, I roll the ButtTaper along the joint to
create a narrow taper on each board (6). This acts just like a
factory taper, with one exception: If you use Durabond or a
similar setting compound, no joint tape is needed. It's the OSB
backer that bonds the two sheets of drywall together, not the
You can use ready-mix compound with the ButtTaper, but you have
to use a special 1/2-inch paper tape and notched knife to bed
the tape (both the tape and the knife are available from the
manufacturer). Instead, I use setting compound, which is faster
because it doesn't require the tape.
The first coat of setting compound should be applied so that it
completely fills and packs the bevel created by the ButtTaper.
I also cover the fasteners, then wipe down the joint in one
pass (7). Since the ButtTaper joint is very narrow, nearly any
size knife will work. Which setting compound I choose depends
on the size of the job. I typically use 45-minute compound for
the first two coats; it's often ready to recoat in as little as
Setting compounds don't shrink much, so the second coat doesn't
require a lot of compound to fill low spots and completely
cover the screw heads. I use a 6-inch knife for this coat,
treating the joint exactly like a factory-tapered joint
I apply the third and final coat of mud — medium-weight
ready-mix — with either a 10-inch or 12-inch knife (9).
Where a new board meets an existing board, I may need to
feather out the mud on one side of the joint to make the
transition smoother. Where two pieces of new drywall meet, the
third coat requires very little mud — just enough to
touch up the second coat. As with a factory tapered joint, a
ButtTaper joint doesn't take much sanding, either — just
a few quick passes with 200-grit paper. The final butt joint is
completely flat, and only 6 to 8 inches wide.
The ButtTaper excels at patches, too. There's no need to load
on the compound, which helps contain the sanding mess.
While the ButtTaper is definitely a departure from the norm, it
produces an end result that's dramatically better than the
alternatives. I've made it a standard part of my remodeling
tool arsenal, and use it for every butt joint I make.Greg DiBernardo owns Fine Home Improvements of
Waldwick in Waldwick, N.J.