Can You Use Foam Pipe Insulation Over Heat Tape?

If you live in a cold climate, you know the dreaded fear of having your pipes freeze. If there's an area of your home where you're especially concerned, it makes sense to do everything you can to prevent it. Heat tape is often a sensible solution. But even better—can you use foam pipe insulation over heat tape and double your protection? We've checked with plumbing experts to bring you an answer.

Using foam pipe insulation over heat tape is a bad idea. Heat tape can crack or break, causing a potential fire hazard if it's near a flammable object like foam insulation. Use a nonflammable kind such as fiberglass instead, and always follow the manufacturer's installation instructions.

Keep reading and we'll explain exactly why using foam pipe insulation with heat tape is a bad idea. We'll also go over some of the other basics on heat tape. We'll cover whether you can use it on PVC pipe, what temperature to plug it in at, how long it lasts, and more.

Insulation for pipes, Can You Use Foam Pipe Insulation Over Heat Tape?

Why You Should Not Use Foam Pipe Insulation Over Heat Tape

Do not use foam pipe insulation over heat tape. It's an unnecessary fire risk.

Some manufacturers may say that their product can be used with insulation. Even then, use insulation from a nonflammable material such as fiberglass.

It's really never a good idea to use foam pipe insulation with heat tape. You may see well-intentioned people who swear they do so, and the old adage "you can do anything once" applies here. It may not be recommended to use foam insulation, but they'll get away with it—until they don't.

High temperature pipe insulation for solar hot-water systems

Heat tape is unlikely to start a fire the first time that you use it. But it's after a few years when you don't realize there's a small crack in the tape that you'll have an emergency. The exposed or faulty wiring can start a fire if it's near a substance like foam insulation.

The answer is simple—don't set a potential fire-starter right next to a fire source. Keep your pipes open so that you can observe any signs of damage and fix them promptly. If you need insulation, at least use nonflammable fiberglass.

Click here to see this fiberglass pipe insulation on Amazon.

Can I Put Heat Tape On PVC Pipe?

You can put heat tape on PVC pipes provided it's the right kind. Not all heat tape is the same, and it's not necessarily interchangeable.

There are various styles of heat tape designed for various purposes. Make sure you have the appropriate one for the task. There is heat tape made for gutters, plastic pipes, or even driveways.

Always check the manufacturer's instructions for use. This will help you decide if the tape is right for your job. Do not use any tape not labeled for use on PVC or plastic pipes due to the risk of overheating and damage.

On plastic pipes, such as PVC, only use heat tape with an automatic thermostat. This controls the temperature of the heat tape. Overheating can cause damage to pipes and even cause leaks.

Also, beware if you have older plastic pipes. Modern PVC pipes can tolerate temperatures of up to 140 degrees. But older plastic pipes, especially thinner, cheaper plastic found in old mobile homes, isn't as durable. Try to determine the material and how hot of a temperature it can stand first.

CPV or PEX tubing is common in mobile homes. This is just as strong as copper pipes, and there's no reason to worry about this kind of plumbing. If your plumbing has been updated, or your home is newer construction, you should be fine.

Home construction with hot and cold blue and red pex pipe layout in pipes and exposed beams

At What Temperature Should You Plug In Heat Tape?

You don't need to worry about the temperature to plug in heat tape. Modern heat tape typically remains plugged in at all times. It should come with an automatic thermostat that only triggers it to heat when the temperature drops.

As a result, it only draws electricity when it is heating. It can remain plugged in the rest of the time, idle.

Repeated heating and cooling can lead to fires. By keeping the tape from heating when not necessary, it reduces the chance of hazard.

Other safety tips include:

  • Only use tape with a three-prong plug.
  • Tape should be UL or CSA certified.
  • Plug the heat tape into a grounded GFCI outlet. This is a quick-tripping circuit breaker that disrupts the flow of power when necessary.

If you know that you won't forget, you can always unplug the tape over the summer. Then, you just make sure to have it on before the temperature drops to 40 degrees. Heat tape won't run until somewhere around this temperature anyway.

Your pipes aren't at risk of freezing until around 20 degrees. But you want the heat on to prevent freezing in advance. Heat tape isn't strong enough to unthaw a frozen pipe.

Burst water pipe

How Long Should Heat Tape Last?

When installed correctly, heat tape can last about three years. Most manufacturers recommend changing the tape after three years, regardless of condition.

However, there is a number of reasons why your heat tape may not last that long. Heat tape used for a surface or purpose that it wasn't designed for rarely lasts. Improper installation also affects the lifespan.

Heat tape used inside the house out of the elements may last over three years. Some manufacturers and brands also last longer, so check your brand's specifications.

During the cold season when the tape will be active, check the tape once before use and then monthly. Look for cracks, animal chew marks, bare wires, or visible heat damage. If signs of deterioration are visible, remove and replace the tape.

Can Heat Tape Be Submerged In Water?

While some kinds of heat tape are moisture resistant, never submerge heat tape directly in water.

It's best to keep as much moisture away as possible. Excessive water will cause the tape to deteriorate and crack faster. The dryer, the better.

Sometimes, like in outdoor use, there's just no way to avoid water altogether. If this is the case, be sure to pick one that is moisture resistant and can take a little dampness safely. And remember—even the tapes that say "water safe" should not be directly submerged.

It's worth noting that there are a variety of heating products that are sometimes mistakenly labeled as heat tape. Some, such as heating cables, can be water resistant.

For this reason, you might find people who say you can put heat tape in water. They are likely actually referring to heating cable. It is rounded and more three dimensional, while heat tape is flatter.

What Is The Difference Between Heat Tapes And Heating Cables?

Electrical tape heater on a pipe

As mentioned, people often use the terms heat tape and heating cable interchangeably. Not sure which one you want? Here's some help:

  • Heat tape is thinner, flatter, and wraps onto or around the pipe. It must make direct contact to heat properly. Heat tape comes in specific lengths, and you can't alter or change the size. Compared to a heating cable, it is flexible and doesn't get as hot.
  • Heating cables are also called pipe heat trace cables. They are not as flexible and generate more heat. Typically round, they can be wrapped in an outer stainless steel coating for better durability and water resistance. It does not need to make complete contact with the pipe to prevent freezing or sit as tight on the surface.

In Closing

When used properly, heat tape can be a great way to prevent water pipes from freezing. But never use heat tape with foam insulation, as it's a potential fire hazard.

Always follow the manufacturer's instructions for use and installation. Make sure the tape is appropriate for the surface and intended use. Only use UL- or CSA-certified tape with an automatic thermostat plugged into a GFCI outlet.

If you enjoyed this, try reading:

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