Pipe insulation and heat cable: what they do, and how to use them safely

Pipe insulation

• Foam sleeves are cheap and easy to fit: match the sleeve to the pipe size, slip it over the pipe, and tape the seams and joints so there are no gaps.
• Insulate all exposed pipe in crawl spaces, garages, attics and pump houses, including elbows and valves.
• IBHS explains why it only goes so far: water freezes when its heat moves into the cold air around it, and insulation slows that transfer. On a long, very cold night, an insulated pipe with no heat source can still freeze. That is why closing vents and keeping the house heated matter too.
• As a stopgap, the American Red Cross notes that even a quarter inch of newspaper can give some protection in places where long freezes are uncommon.

Heat cable (heat tape)

Heat cable runs along a pipe and warms it. Self-regulating cable adjusts its output to the temperature; older constant-wattage tape usually relies on a thermostat. The Red Cross suggests using UL-listed products.

The CPSC's safety rules

• Buy the cable made for your pipe's diameter and length.
• Follow the manufacturer's installation instructions exactly.
• Do not overlap the cable on itself unless the instructions allow it.
• Put the cable directly on the pipe, never on top of pipe insulation.
• Do not cover it with insulation unless the maker says to. If you do, use a non-flammable material such as fiberglass, and never more than recommended; over-insulating can cause a fire.
• Have old heat tapes inspected, ideally by an electrician, and replace any with cracked insulation or bare wires.

Where it matters most in Newberry County

• The main supply where it rises out of the ground under a manufactured home.
• Well pump houses: the pump line, the pressure switch and the tank piping.
• Pipes near crawl space vents or access doors that have frozen before.
• Outdoor lines that cannot be drained.

Plug it in safely

Use a grounded outlet rated for the location. Many manufacturers require ground-fault protection, so check the instructions. Test the cable each fall before the first freeze, and look it over for damage from rodents or sun.