Fixed Outdoor De-Icing & Snow-Melting Equipment

Article 426 covers the fixed outdoor systems that keep surfaces clear of ice — embedded pavement heating, roof and gutter de-icing cable, and heated walkways. Because they operate in the wettest, harshest spot on a property, the article requires ground-fault protection of equipment (GFPE), sturdy installation, and correct sizing for a continuous load.

It addresses how the heating cable is embedded or attached, protection where it enters buildings, and identification so future workers know a live heating system is present. The overriding concern is a high-current heater exposed to melting water, which demands both fire and shock safeguards.

When it applies

This covers fixed outdoor de-icing and snow-melting systems, the heating cable and panels embedded in driveways, walkways, roofs, and gutters. Because it is heating equipment out in the wet and cold, the article demands ground-fault protection of equipment, proper cable spacing, and correct terminations at the cold-lead splice.

Common mistakes

• Skipping the required ground-fault equipment protection, a nicked cable in a wet slab is exactly what it guards against.
• Crossing or overlapping heating cable so it overheats itself at the crossing point.
• Botching the factory cold-lead-to-heating-cable splice, that joint is where moisture and failure start.

In the field

Before the concrete truck shows up I megger every heating cable and log the reading, then megger again after the pour. A rake or a boot can nick a cable during placement, and the only way to catch it is a before-and-after test while you can still fix it.