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Until a few years ago, there were two
drywall problems that could not be satisfactorily finished: the off
right angle and the butt joint.
A finisher will not have a
concern with his seams, nails/screws and right angles, but the butt
joint is still a concern as the off right angle problem has been
solved with the plastic tapes such as Strait-Flex and No-Coat. The
curvature of the butt joint is still a concern especially with
glossy paints and its tendency to crack or ridge. In the current
method of doing butt joints, the two boards are bonded on a 1-1/2"
stud or joist that is mainly crooked, not perfectly straight, and
which will shrink due to the moisture of the stud or joist causing
cracking or ridging. Simply, the 1-1/2" width of a wooden stud or
joist and the 1-1/4" width of steel stud is not adequate to
properly bind the two butt joint boards. The USG Gypsum
Construction Handbook addresses these butt joint failures on page
115 with their “Back- Blocking Application”, which states “The
Back-Blocking System enables the floating of end butt joints between
studs or joists and makes it easier to form a good surface over a
twisted stud or joist”. Unfortunately USG’s method is cumbersome
and labor intensive, although “the system has been widely used for
years and produces outstanding results”.
The Gypsum Construction Handbook
on page 108 under ‘Single Nailing Application”, states: “Drive nails
at least 3/8" from ends or edges of gypsum board”. Wooden
studs/joists due to their not being perfectly straight, does not
allow enough space to properly space the nails 3/8" from the butt
board end. If a nail or screw is placed at the very edge, it losses
its holding strength as do nails that are driven at the edge of any
wood resulting in wood splintering. The same applies to drywall!
Essentially, the traditional method of binding two butt boards on a
framing member is not adequate enough in the long term to prevent
butt joint cracking or ridging.
The Gypsum Construction Handbook
also states on page 105: “Butt all joints loosely. Never force
panels into position”.
It is virtually impossible to
properly install drywall butt joints following the Gypsum
Construction Handbook guidelines in the current traditional method
on a stud or joist, and for that reason butt joint cracking and
ridging is a constant problem.
The ButtTaper system eliminates
this impossibility by allowing proper screw spacing from the board
ends, offers a wider surface area to bind the two boards together,
eliminates wood shrinking while offering a flat butt joint in
minimum labor time at reduced material costs. |