Best for metal roofs in roof and pipe heat cables
A pre-assembled, self-regulating plug-in cable for roofs, gutters and downspouts, including metal and shake roofs, that turns its own output down as it warms. It keeps melt water draining; it does not clear the roof.
Our score: 7.8/10 out of 10Researched, not lab-tested
- Use
- Pipes, roof and gutters
- Cable type
- Self-regulating
- Cable length
- 50 ft
- Output
- 8 W/ft
Is it right for you?
Pros
- Self-regulating: output drops as it warms; Raychem says overlaps can't overheat
- For shingle, shake, rubber, tar, wood, metal and plastic roofs
- Pre-assembled with a 6 ft cord and lighted, grounded plug
- The same cable also protects metal or plastic pipes up to 2 1/2 in
- Installs down to 5 °F
Cons
- Needs a ground-fault protected, rain-sheltered outlet; no extension cord
- Melts drainage paths only; it won't clear snow or stop it sliding off
- Raychem's insulation test needs a 2500 V megohmmeter, an electrician's tool
- No UPC published, so buy by catalog number FG1-50P
- Best for
- Homes with metal, shake or other roofs the cheaper constant-wattage kits exclude, or owners who want a plug-in roof cable that throttles itself back.
- Not for
- Homes without a ground-fault protected outdoor outlet near the eaves, or anyone hoping to keep a whole roof clear of snow.
Our verdict
The Raychem FrostGuard FG1-50P is a 50 ft, 120 V self-regulating cable that comes ready to use, with a 6 ft cord and a lighted, grounded plug. Self-regulating means the cable puts out more heat where it is cold and less where it is warm: Raychem gives about 8 W per ft in ice or snow at 32 °F, and says it cannot overheat even where runs overlap or lie close together. That is the main difference from constant-wattage kits such as the Frost King RC60.
Raychem approves it for shake, shingle, rubber, tar, wood, metal and plastic roofs and for metal or plastic gutters and downspouts, so it is our pick where other kits are ruled out. Like any roof cable, it drains melt water rather than clearing snow; Raychem points to snow guards or snow fences to stop snow sliding. The same cable can protect metal or plastic water pipes, and the short FG1-6P is the pipe length. It is sold in Canada through electrical distributors as well as in the US.
Installing it safely
Raychem’s sizing rule for a shingle roof with no overhang is about 2 ft of cable per foot of roof edge, more for overhangs, plus the gutter and downspout runs. It is fixed with Raychem H913 or H914 roof clips (about 10 per 7 ft of edge) and an H915 hanger bracket at each downspout. Never run it under a roof covering or through walls, ceilings or floors, and keep it where it can be reached. Plug it only into a ground-fault protected outlet sheltered from rain, with no extension cord: Raychem says each circuit needs ground-fault protection because ordinary breakers may not stop arcing in a damaged cable.
Safety: every fall, check the cable unplugged for cracked or charred insulation or bare wire, and replace a damaged cable at once, as the US Consumer Product Safety Commission advises.
After installing, Raychem tests insulation resistance with a 2500 V dc megohmmeter; below 1000 megohms the cable is replaced, never repaired. Installation falls under the US National Electrical Code (Articles 422, 426, 427) and the Canadian Electrical Code Part 1, Section 62. See our ice dam guide and the other cables on our heat cable page.
Specs
Raychem FrostGuard 120 V Self-Regulating Heating Cable, 50 ft (FG1-50P)
Use
| Use | Pipes, roof and gutters |
|---|---|
| Cable type | Self-regulating |
| Pipe types | Metal or plastic water pipe, not garden hose |
| Roof types | Shingle, shake, rubber, tar, wood, metal and plastic roofs; metal or plastic gutters |
| Largest pipe | 2.5 in |
| Lowest install temperature | 5 °F |
Electrical
| Output | 8 W/ft |
|---|---|
| Thermostat | None needed (self-regulating cable) |
| Ground-fault protection | Needs a GFCI-protected outlet |
| Voltage | 120 V |
Other details
| Cable length | 50 ft |
|---|
Maker’s figures, checked 4 Nov 2026.
Raychem FrostGuard FG1-50P questions
Can I put the FrostGuard on a metal roof?
Yes. Raychem approves FrostGuard for metal roofs, as well as shake, shingle, rubber, tar, wood and plastic roofs and metal or plastic gutters and downspouts.
Is self-regulating cable safer than regular heat tape?
It turns its own output down as it warms, and Raychem says it cannot overheat even where runs overlap. Constant-wattage cables such as the Frost King kits must never overlap. Either kind still needs a ground-fault protected outlet and a yearly check.
Does it need a GFCI outlet?
Yes. Raychem requires ground-fault protection on every FrostGuard circuit and says to plug it only into a ground-fault protected outlet sheltered from rain, with no extension cord.
How much cable does my roof need?
Raychem’s table starts at about 2 ft of cable per foot of roof edge on a shingle roof with no overhang, with more for overhangs, plus the length of each gutter and downspout run.
