Technical Specifications
Keep Gutters and Downspouts Flowing all
Winter Long with
Frost King
®
Roof De-icing Cable
Roof and gutter de-icing cables help end costly ice damage by prevent-
ing ice dam formation and promoting the free flow of water through
gutters and downspouts to ground level.
This product is for the sole intended use of preventing ice dams from
forming on inclined roofs with tab shingles, in gutters and in down-
spouts. This roof de-icing cable is not intended for use as a snow-melt-
ing system to clear roof of ice and snow. Never install on a flat roof.
Never install on combustible materials. Not suitable for use on metal
roofs: contact Frost King for appropriate cable solutions.
Includes: De-icing Cable, Shingle Clips, Cable Spacers, Installation
Instructions and Electrical Panel Labels.
DOWNSPOUT
GUTTER
ROOF
SINGLE CABLE INSTALLATION
DOWNSPOUT
GUTTER
ROOF
DOUBLE CABLE INSTALLATION
Cable Installation Patterns
One cable may cover both roof and gutter
areas, or separate cables can be used.
DESIGNING A SYSTEM
• Sun exposure, prevailing weather direction and roof shape may
result in different conditions at different points on a roof. Several
controls and shorter cable runs may be appropriate. If only one
control is used, it should be located to respond to the worst icing
conditions.
• The length of roofline alone does not determine cables/
controls needed. Consider: roof design and size; gutter and down-
spout location; number of sides of a typical, peaked roof to be pro-
tected.
• Use of a temperature and moisture sensing control,
such as the Frost King RS-2 Roof Sentry, is highly
recommended. Using a proper control will ensure the system is
automatically energized only when needed. Use one RS-2 for each
Frost King cable installed.
• Use a ground fault protection device or outlet.
• Weather-proofed outlets of sufficient quantity and amp rating are
required within six (6) foot cord-set length of the cable/control
starting point.
FIG. 1
DETERMINE ROOF DE-ICING CABLE NEED
Measure Roof Overhang
Install cable over unheated portion of roof — normally roof area
above overhang. This helps to ensure that water flowing onto the
unheated roof area will be able to flow to the ground. Installing
cable in valleys, gutter and downspouts as well creates an ice-free
pathway for water to drain completely from eaves and gutter. For
your de-icing cable requirements, determine the roof overhang (E in
figure 1) with corresponding multiplier as follows:
* Length of cable required per foot of roof length. Note: Multiplier
shown includes 1 foot of gutter cable for each foot of roof edge.
MULTIPLIER TABLE
Roof Overhang Roof Overhang
Overhang Multiplier* Overhang Multiplier*
12˝ / 30 cm 4.0 48˝ / 120 cm 8.1
24˝ / 60 cm 5.3 60˝ / 150 cm 9.6
36˝ / 90 cm 6.8 72˝ / 180 cm 11.2
FIG. 2
C
A
B
D
Measure Length of Roof
1 Measure horizontal roof length to be covered by cable; multiply
by Overhang Multiplier to determine total cable length for roof
area.
2 Add cable for downspout (A in figure 2). NOTE: if
a downspout is located anywhere other than at the
end of the cable routing, that downspout will require double
length of cable (B in figure 2).
3 Add extra cable for valleys (6´ per valley, C in figure 2) and
around dormers (D in figure 2).
Example: 24 feet of roof, 24 inches overhang (therefore using
Overhang Multiplier of 5.3), 2 downspouts at 10´, one at end of cable
run, and one at midrun, 1 valley, 1 dormer with 30´ perimeter.
Cable length = (24 x 5.3) + 10 + 20 + 6 + 30 = 193.2 feet
In this example, select HC200 (200´), as it is closest to 193.2 feet.
Use excess cable in valley or downspout.
Compare your total to standard lengths available from your retailer.
Specify closest product possible to your total need. De-icing cable
cannot be cut or altered; doing so voids the warranty. Once cut, it
cannot be repaired.
RS-2