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Figure 11. Standard base for combustible floor.
Figure 13. Typical roof mounting with standard
combustible mount base.
Figure 12. Typical roof mounting.
Figure 10. Outdoor location installation.
Figure 9. Incorrect outdoor installation.
WINDOW
OR GRILL
INDOOR
ROOM
4 ft.
(1.2m)
4 ft.
(1.2m)
4 ft.
(1.2m)
Concrete slab must extend out a
minimum of 12 in. (305mm) on
all sides.
NATCO
UNIT
(Side View)
Base For Combustible Floors
Roof - Wood and Steel Construction
Mounting Platform must extend
out a minimum of 12 in.
(305mm) on all sides.
NATCO
UNIT
(Side View)
Base For Combustible Floors
Raised Mounting
Platform (Wood)
20 Gauge
Galvanized
Sheet Metal
Cap
Roofing
Base Rail
Flashing
Roof
NATCO
UNIT
(Side View)
Base For Combustible Floors
Flashing
4x4 Stringer
Roof
Base Rail
20 Gauge
Galvanized
Sheet Metal
Cap
Roofing
Avoid locations where wind deflection off nearby
structures might cause wind loading and downdraft
conditions. Where downdraft conditions exist, locate
the heater at least 3 feet (0.91 m) from the structure.
2C-3. Flooring - Typical Installation
Do not install the heater directly on carpeting
without placing a non-combustible platform between
the carpeting and the heater. If the heater is installed in
a carpeted alcove, the entire floor of the alcove must
be covered by a non-combustible panel. The panel
must be strong enough to carry the total weight of the
heater and all piping, pumps, and any other equipment
attached to the heater. For rooftop installation, see
Figure 11 through Figure 13.
2D. Combustion and Ventilation
Air Supply
All indoor installations must have openings to
outside air for combustion, ventilation and dilution of
