Tips for Selecting and Installing Gutter Heater Heat Tape
Learn more about Gutter Heater Tape
Gutter heat tape is a necessity in every location where heavy snow and ice formations are prevalent. The gutter heat tape or cable is used on rooftops to ensure that they properly cared for and so that ice dams do not form on roof surfaces, in gutters, or downspouts. Here is what you need to know about installing it:
What is Gutter Heat Tape Used for?
The gutter heat tape or cable is run in special patterns across roofs, in gutters and along downspouts where ice usually forms, collects and eventually creates what are known as ice dams. Installing gutter heat tape is meant for the prevention of the ice dams, not for getting rid of them once already formed. This product is also not meant for clearing the roof of ice or snow, but merely for creating a clear pathway for already melted snow and ice to drain to the ground.
When Do You Need To Install it?
The best time for installing gutter heat tape is during times when there is no snow or ice on the roof. This will allow you to best determine where to install the cabling and ensure that you do this effectively. So, how do you know where on the roof you need the deicing cable? Well, it is usually where ice dams form on the roof and you can figure this out by looking at where the sun hits the roof the most, the prevailing wind direction and the shape of the roof. The ice dams normally form where snow melts on the upper parts of the roof and then collect on ice and snow underneath that has not melted yet. So, this means that around dormers, on certain sides of the roof edges, and sometimes under skylights are potential problem areas that need to be addressed.
Electrical and Roofing Requirements
Although installing the gutter heat tape does not require any professional skill level, you might want to consult a professional if you are worried about working on roof tops and if you are concerned about the various electrical requirements that you should follow in order to be safe whilst you are doing this job. Some people decide to call in an electrician or roofing contractor to help with this project. If you want to go it alone, here are the main electrical and safety requirements that you need to adhere to:
- Firstly you need to use a 120 Volt A/C receptacle that is classified for outdoor use.
- This must be grounded.
- It must have ground fault protection.
- It must be on a circuit with the correct ampere (current) rating.
- The receptacle must have an on/off switch as well as an indicator or pilot light.
- It must be fully protected from the weather.
- It must be within 6 feet of where the cable starts on the roof.
- You should not use an extension cord with the gutter heat tape.
- Ensure that the heated part of the cable does not touch another part of the cable or overlap in any way, as this will cause it to overheat.
- You should not operate the cable when the weather is above 50 degrees Farenheit (10 degrees Celsius).
- Don’t install the cable near to any heating sources like a chimney or exhaust vent.
- Do not alter or cut the cable or modify it in any way, including paint it, use chemicals on it or use adhesive on it.
- Keep all combustible items away from the heat tape including pine needles, seeds, leaves or wind-blown trash, and similarly do not attach the cable to any combustible part of the roof like wooden eaves.
- Make sure that there is a half inch space between any gutter guards and the gutter heat tape.
- Don’t use any damaged tape, which includes tape that is cut, brittle, discolored, charred or that has exposed wiring.
- You should only install gutter heat tape on inclined roofs that are made using asphalt shingles and that have plastic or metal gutters and downspouts.
What Other Materials Do You Need for the Installation?
Before you start your installation job, you must make sure that you have all the materials and items you need to get the job done. Every gutter heat tape kit should contain the cable, the cable spacers, shingle clips, and labels for the circuit breakers and the on/off switch. Other than this kit you will need a ladder, tape measure, putty knife for prying the shingles, marking chalk to mark the pattern of the cables on the singles, weighted string which is used to measure the downspouts and also pull the cable through the downspouts, and a file to remove any sharp edges.
Estimating How Much Cable you Need?
Due to the fact that you can’t cut and reattach, or alter the cable in any way, you must ensure that you accurately estimate the amount that you will require.
For a typical roof you will work out the amount of cable you need as follows:
Measure the length of the overhang. Now, you will need to first calculate the overhang multiplier using the measurement you just took. If the measurement is less than 12 inches or 30 centimeters use the multiplier, 4 for a roof with a gutter and 3 for a roof without a gutter. Then you will multiply this by the length of the roof. The rest of the overhang multipliers are as follows:
24 inches = 5.3 multiplier for roof with gutter and 4.3 for roof without gutter.
36 inches = 6.8 multiplier for roof with gutter and 5.8 for roof without gutter.
48 inches = 8.1 multiplier for roof with gutter and 7.1 for roof without gutter.
60 inches = 9.6 multiplier for roof with gutter and 8.6 for roof without gutter.
For any measurements that are not listed, simply estimate according to what is shown here.
To estimate the amount of cable you need for dormers all you have to do is measure the distance around a dormer and multiply this by the number of dormers (provided that all the dormers are the same size).
To estimate the amount of cable you need for the valleys, measure the number of valleys and multiply this by 6 feet or 1.8 meters.
Lastly, to see how much cable you need for the downspouts, measure the length of the downspouts and times this by 2 (because you will double run the cables in the downspouts) and then times this by the number of downspouts. You will use the same formula for calculating the amount of heat tape required for the gutters.
The gutter heat tape is sold in kits ranging from 20 feet or 6 meters to 240 feet or 73 meters and it is recommended that if you have a large area to cover or there is a significant distance between areas on the roof, that you purchase 2 or 3 smaller kits instead of 1 large kit.
How to Arrange and Attach the Gutter Heater Cable?
Once you have worked out how much you require, all that is left is installing the gutter heat tape according to specific patterns. Basically you will lay the cable in a zigzag or triangle pattern with the base of the triangle being about 15 inches, and the height of the triangle being measured according to the length of the overhang. For an overhang of 12 inches or less the triangle height should be 3 shingle rows. This increases up to 13 shingle rows where the overhang is 66 to 70. At the bottom of each triangle, the cable is hung slightly over the edge and clamped to form a drip loop.
For a skylight the triangle pattern is also used, but the triangle height will just be lengthened to reach the skylight. For valleys, the cable will be run up and then back down again, and for downspouts this is the same.
With these tips, you will be able to work out just how much cable you need to purchase and installing gutter heat tape on your house will be easy.