Lowe's, The Home Depot, Amazon.com and GlobalIndustrial.com are good places to buy electric roof de-icing cables and accessories. Pricing varies depending on the vendor, cable length and optional features such as a manual switch or automatic thermostat operation.
Lowe's and Amazon.com offer products primarily from EasyHeat with cable lengths available ranging from 30 feet to 200 feet. The units come pre-assembled and ready to install, but must be connected to a power supply with a ground fault interrupter.
The Home Depot and GlobalIndustrial.com offer de-icing products manufactured by Frost King. Frost King de-icing cables come in similar lengths, configurations and electrical requirements as the EasyHeat products. All Frost King cables include shingle clips for roof mounting and come with a two-year manufacturer's warranty.
Roof de-icing cables are typically 120 volt AC and must have a connection to the home electrical supply. This is typically accomplished by connecting to an electrical outlet on the home's exterior or installing wiring directly to the house's electrical panel. De-icing cables typically require about 5 watts of electricity per foot of cable. Additional accessories available from most suppliers include splicing clips to connect multiple cables for a larger coverage area, electrical cable controllers to route power to multiple cables, and automatic controllers.