DuraVent Type B Gas Vent User Manual
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a gas vent support or firestop spacer must be
provided where the vent passes through the
ceiling. The ceiling opening is framed, using
the same sized lumber as the existing joists,
to fit around the raised edge of the gas vent
support, which is pushed up into the ceiling
from below. The hanger straps are nailed to
the framing using 1 1/2-inch box nails to hold
the gas vent support firmly, and the clamp is
then tightened around the vent pipe. Firestop
spacers must be utilized in multistory buildings
at each level where the vent passes through
a floor.
Sections of pipe are connected to each other
by pushing them firmly together and twisting.
Screws are not required. If screws are desired,
for 3- to 6-inch diameter pipe, use 1/4-inch
sheet metal screws. For larger diameters up
through 16 inches, use 3/8-inch sheet metal
screws. For 18-inch and greater diameters,
use 3/8-inch sheet metal screws. under no
circumstances, penetrate the inner liner with
screws.
any portions of the vent assembly that extend
through accessible or occupied spaces must
be enclosed with an enclosure that is at least
1-inch away from vent pipe.