A.Myron Ferguson, a
drywall contractor in Galway, N.Y., responds:
It takes about 1,000 screws to hang 1,000 square
feet of drywall, so it’s not uncommon to
have a dozen or so screw pops in an average
house.
Screws set too deeply might be fine when the
drywall is sanded, but may pop when
there’s structural movement or an impact.
Also, insulation can push against the drywall and
prevent it from being fastened tight to the
framing; later, pressing the drywall back against
the framing can cause pops to occur. And finally,
when framing dries and shrinks, a gap can open up
between it and the drywall; screws that are too
long are more likely to pop when this happens than
properly sized drywall screws, which should
penetrate the framing only about 5/8 inch.
But it’s unusual to have hundreds of
screw pops. While conditions are seldom ideal on
any site, most drywall installations experience
minimal popping. In your case, it’s likely
that a “perfect storm” of factors
— lumber with relatively high moisture
content, damp drywall, perhaps high humidity and
low airflow, even improperly set screws —
all contributed to the problem.
Most of the excessive popping I’ve
experienced has occurred along the top plate, so
now I avoid fastening drywall within about 7 inches
of the ceiling. I’ve found that using
drywall adhesive helps reduce fastener pops and
provides extra insurance against minor structural
movement or improperly set screws. (I always
specify adhesive when working with an installation
subcontractor.)
Working with dry framing helps, too. Whenever I
can, I bring the drywall inside ahead of time and
allow it to acclimate (same as with hardwood
flooring), and I try to control temperature,
humidity, and airflow before, during, and after the
drywall work.