Use and Care Guide

17
Conditions
PAPER PROBLEMS
Joint Blisters
Wallboard Blisters
End Ply Separation
CRACKING PROBLEMS
Edge Cracking
Cracking
Inside Corner Cracking
Probable Cause
Too little joint compound under
tape. Joint compound too dry
before embedding tape. Improper
bedding of the tape into the joint
compound. Loss of bond (see bond
failure). End ply separation.
Ruptured wallboard ends or edges.
Joints too wide and unfilled.
Usually caused by ruptured board.
Mishandling of wallboard,
especially when damp or wet.
Fast drying with low humidity.
Rapid temperature and humidity
changes. Improper application.
Joint compound too thin or too
heavy under tape. Edges of tape
too thick. Excessive wet expansion
and contraction of joint tape. Poor
bond (see Bond Failure).
Adverse drying conditions. High
temperatures and low humidity
and drafts or low temperature and
high humidity. Joint or topping
compound applied in excessive
thickness.
Joint too wide or not filled.
Improper drying between coats.
Excess thickness of compound over
tape at apex of corner. Extremely
fast or slow drying conditions.
Applying compound to both sides
of inside corner at same time.
Preventive Action
Follow joint compound mixing and
application instructions. Embed
tape properly into ample joint
compound. Cut out any ruptured
ends or edges of wallboard and fill
all wide holes and joints with
Quick Set prior to taping (see end
ply separation).
Check field of board prior to deco-
ration for imperfections. Make any
necessary repairs.
Allow wallboard to thoroughly
dry, tear back all loose face paper
prior to taping.
Correct drying conditions to avoid
rapid surface drying. Keep tempera-
tures and humidity as consistent as
possible by controlling ventilation.
Use roller to wet joints with water
prior to each joint treatment opera-
tion. Use Quick Set or ProForm
joint compounds and tape. Embed
tape properly, avoiding excessive
compound under tape (maximum
of 1/32" thickness of compound
under edges of tape) and wipe
down tape immediately. Use job
prevention for bond problems.
Fill all wide wallboard joints
with Quick Set. Correct drying con-
ditions. Apply thinner layers of joint
or topping compound. Allow thor-
ough drying between layers.
Fill wide joints with Quick Set prior
to taping. Embed tape properly,
allow to dry. Apply compound to
one side and allow to dry, then
treat other side.
Corrective Action
Repair tape blisters by slitting and
filling with joint compound and
smooth out with finishing knife.
Cut out other loose areas, fill with
joint compound when necessary.
Let dry, then re-tape and finish.
Before decoration, cut out loose
area, fill flush with joint compound,
if deep. Tape and finish.
After joints are finished, determine
the distance of looseness from the
mill end. Make a cut on each side
of the tape across the wallboard
and a cut at each end, forming a
rectangle around the loose area.
Peel off loose paper, tape joint.
Once dry, fill flush with joint
compound. After compound dries,
finish with one or more coats of
joint or topping compound, feath-
ering beyond the cutout area.
Correct drying conditions during
repairs and painting when edge
cracks appear before second finish-
ing coat. Brush one or two coats
of good quality flat latex paint about
4" wide over tape, then apply finish-
ing coat. When cracks appear after
finishing coat or painting, apply two
or more coats of good quality flat
latex paint over cracks that are flush
with surface to bridge them before
decoration. Where cracks are curled,
groove out cracks and apply one
coat of flat latex paint. Once dry,
fill with Quick Set or ProForm
joint compound.
Additional coats of joint or topping
compound will fill the cracks with-
out reoccurrence.
Fill wide cracks with joint or top-
ping compound. For hairline cracks,
run a pointed object (10D or 16D
nail) along the apex of corner with
adequate pressure to close crack.