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Milcor hatch covers open
easily to 90 degrees. Operation is assisted by enclosed
torsion bar or torsion coil spring operators. Automatic
hold-open arms keep doors securely open. |
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The clear hatch opening
is virtually unobstructed, with only a narrow hold-open arm at
one corner and the torsion bar or spring mounted out of the way
in the cover or frame. |
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Heavy, closed cell,
rubber gaskets factory-applied to the units provide a barrier to
weather penetration and drafts. Latching devices with
inside and outside handles hold hatches tightly closed. |
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Hatches are available in
several materials, including galvanized steel, aluminum,
aluminum cover with galvanized steel curb, or stainless steel.
Galvanized steel is prime-painted with rust inhibitive primer. |
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Hatch covers are
insulated to keep heat in during winter and to repel the sun's
heat in summer. Models M, RBS, and RCS feature
composite-design cover construction for insulating efficiency.
The rigid extruded polystyrene foam insulation in the covers
provides U-factors ranging from 0.093 to 0.173. Milcor
roof hatches are also available in RB, RC, and RD models with
fiberglass-insulated covers providing a U-value of 0.26.
Curbs are insulated with 1" thick rigid fiberboard insulation. |
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Models M, RBS, and RCS
composite cover design provides load-carrying strengths of 70
psf. RB, RC, and RD models can carry a live load of 40 psf. |
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Milcor roof hatches are
available in single- and double-leaf configurations, depending
upon the size of the units. Single-leaf models M, RBS, and
RD-1 are available in 3'-0" x 2'-6" and 3'-0" x 3'-0" with a
torsion bar mounted in the cover. RB, RC, and most other
RD models are available in all sizes with the torsion spring
mounted in the frame, offering added strength with larger sizes.
Standard size double-leaf units range from 5'-0" x 11'-0" to
8'-0" x 8'-0". |
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Hatches can be fabricated
in special sizes, shapes, or other modifications to meet special
needs. Consult Commercial Products Group for details. |
Selecting the Proper Size
Hatch
The
angle at which a person ascends to the roof determines the size
hatch required for convenient use. If a ladder is used,
the hatch may be rather small since the person comes straight up
to the roof. As the angle of ascent decreases, the hatch
must be larger to prevent head bumping accidents.
Recommended minimum sizes for various types of roof access are
shown below. If movement of bulky materials through the
hatch is anticipated, double-leaf hatches with openings up to 66
sq. ft. or larger are available. Recent changes to the
International Building Code (IBC) require 16 sq. ft. openings as
the standard for various structures.
Note: the second dimension on
hatch sizes denotes the length along the hinge side.
Roof Hatch Options
Stainless steel hardware
is available for roof hatches to be installed in highly
corrosive environments. Roof hatches can be
equipped with motor operators for opening and closing the covers
from a remote 3-position selector switch. |
Roof Hatches Overview
Roof Hatches Quick Reference Chart
Single-leaf, Torsion Spring Mounted in Cover
Single-leaf, Torsion Spring Mounted in Frame
Double-leaf Hatch
Upright Safety Bar
Safety Railing |