Understanding
the UL Fire Resistance Directories
What is the difference between
ôregularö and ôtype xö gypsum wallboard?
ôeXtraö fire resistant
Type X
wallboard, which is typically required to achieve fire resistance ratings, is
formulated by adding
noncombustible fibers to the gypsum.
These fibers help maintain the integrity
of the core as
shrinkage occurs, providing greater resistance to heat transfer during fire exposure.