POSITIVE
PRESSURE - Page 3
POSITIVE
PRESSURE DOOR INFORMATION
-
METHODS
OF COMPLIANCE
Positive pressure openings can be accomplished in two basic
ways:
The first is described as Category "A" doors.
DOORS-NO ADDITIONAL EDGE-SEALING SYSTEM REQUIRED
This category includes doors evaluated without any intumescent
on
either the frame or door. It also includes doors evaluated with
intumescent
incorporated into the edge of the door by manufacture or licensed
machiner.
The second
method is called Category "B" doors.
DOORS-ADDITIONAL EDGE-SEALING SYSTEM REQUIRED
This category includes doors evaluated with an intumescent applied
to the
frame-either surface applied or built in.
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S LABEL SMOKE RATING
Many positive pressure openings will also require a smoke seal. An
"S" label requirement indicates the opening needs to have
Smoke and Draft Control Gasketing. This category "H" includes
gasket systems that are surface-applied (such as kerf applied, adhesive
backed or mechanically attached) to frames or doors. It includes
gasketing for the meeting edges for use in pair and double egress
assemblies. This category covers gasket systems that have been evaluated
for use in positive pressure rated assemblies but not provide an
edge-sealing system to the opening as described below.
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EDGE-SEALING SYSTEMS
This category "G" includes intumescent-type systems that
are surface applied (such as kerf applied,
adhesive backed or mechanically attached) to frames or doors. It
includes seals for meeting edges for use in pair and double egress assemblies.
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DOOR SPECIFICATION DESCRIPTIONS
Section G-1, of the WDMA I.S. 1-A lists the different types of flush
door construction available in
the industry. Fire rated doors for positive pressure openings are
designed with "PP" suffix. Stile and Rail
door co construction as described by WDMA I.S.6A are also
available for positive pressure openings
based on specific manufacturer's approvals.
The change to positive pressure requirements can be confusing as the new
codes are implemented
and the various door, frame and hardware manufacturer's develop new
products to meet those
requirements. For additional information contact your Architectural Wood
Door Manufacturer or WDMA.
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