What Is Heat Tape?
Heat tape (sometimes called heat cable) is a coated electrical wire that can be applied to water pipes to keep them from freezing and bursting. A similar product can also be used along your roof's edge to prevent ice build-up in your gutters and eaves. Each winter, ice dams building up along roof overhangs cause damaging leaks inside many hundreds of homes. Ice dams occur because snow and ice on the roof melts from interior heat, travels down the roof and freezes again as it reaches the unheated overhangs.
Over time, this frozen melt-off builds up into a dam barrier that causes ice and water to back up under the shingles, causing damage interior ceiling and wall surfaces. And the sheer weight of ice dams can damage the roof overhangs and gutters.
Heat tape is a powerful tool to prevent ice and snow from building up on the roof and creating ice dams, which can be difficult and expensive to remove once they form.
While heat tape is certainly a worth-while investment for a homeowner, the process of installing it can be a challenging task, largely because the work needs to be done on a ladder. It requires at least one partner with you to stabilize the ladder as you execute the installation. Hiring a professional roofing contractor may be the best choice, as they are well versed in the installation and will ensure proper placement, as well as electrical safety.
If the heat tape is installed incorrectly or if the wrong type of heat tape is used, there could be possible fire hazards.
This is also true for heat tape that is old and deteriorated. If your home has heat tape that has been installed before you moved in or is more than five years old, it is a good idea to have it checked for proper function.
Be aware that the heat tape designed for roofs and gutters is different than the heat tape used to insulate pipes.
If you plan to do the installation yourself, be sure you have the correct tape! This should be obvious from the packaging, but there are quite a few options on the market and using the incorrect product for the project could create a fire hazard.
Installing Heat Tape
- Your first step in the installation is to determine the length of heat tape you need. Measure the perimeter of your roof line, being sure to take careful note of your measurement. Next, measure your overhang or eave. If the eave is 12 inches in depth, multiply the roof-line measurement by 2. If the eave is more than 12 inches but less than 24 inches deep, multiply the roof-line measurement by 3. If the eave depth is more than 24 inches but less than 48 inches, multiply the roof-line measurement by 4.
- Calculate the length of all of the downspouts and add this footage figure to the perimeter measurement and eave measurement sum to arrive at the number of feet of heat tape you will need to purchase to effectively cover your roof.
- Keep in mind that the heat tape will need to be plugged in once installed, so make sure it is installed near an electrical source. The heat tape you purchased will have a controller unit. This is the unit that will provide power from an electrical source to the tape. It is important to position this controller unit near the power source before you begin your installation.
- Loop the heat tape up and down in a zigzag pattern, starting from about 12 inches up the roof slope and then position to hang down over and beyond the gutter by at least 7 inches. Repeat this pattern as many lengths as necessary to cover the entire perimeter of the roof and gutter system.
- Plastic clips will be provided with the tape you've purchased. Attach the heat tape to the roof and gutters using these clips in the pattern outlined in the manufacturer's specification. You may need to adjust slightly, depending on the perimeter of your roof and home style.
- Connect the lengths of heat tape together and plug the end into the controller unit. Mount the controller unit to the underside of the eaves along the soffit, near to the power supply, with the screws supplied in the purchased kit. Connect the power cord from the controller unit to the power supply outlet and attach the power cord to the side of the building.
Disadvantages of Heat Tape
While heat tape is relatively easy to install and use, it does have some disadvantages that should be considered before installing. There are other highly effective solutions to reducing ice damming if you determine that heat tape is not the best option for your home.
- Improper installation is ineffective installation. In order for the heat tape to do its job correctly, it needs to be placed in areas where it can be most effective. This means the tape needs to be installed precisely where roof melt-off reaches places where it can freeze again and create ice dams. This is a powerful example of the benefit of hiring a roofing contractor for the installation. A good contractor can determine which areas will give you the greatest protection and which areas may not require any heat tape.
- Heat tape uses a significant amount of power to generate enough heat along the entire length of the tape. If the tape is placed on the same circuit as other high-drawing appliances, the heating tape can trip the breaker or blow a fuse. It could even leave you without heat if your furnace blower motor is on the same circuit.
- Lastly, to allow the heat to melt the ice, the wire must be significantly thinner than normal wiring. As this wire is exposed to extreme heat and extreme cold, the insulation can break down and expose the bare wire, creating a fire hazard. To avoid any issues, make sure you regularly inspect your heat tape to ensure there are no areas of bare wire being exposed.
While the benefits of heat tape mostly outweigh the potential problems, it is a good idea to consult with a roofing contractor to find out which option for preventing ice dams is best for your home. If you should find that heat tape is the best solution, make sure it is installed properly, functions correctly and is inspected regularly.