Myth #1:
“If your roof eave is 5 feet, then you need a roof edge ice melt system that will melt back 5 feet”

. . . FALSE!

The Truth:

Ice dams develop where the ice meltwater drips off a usually bare roof edge. This is the coldest spot on a roof since the snow melt water is fully exposed to ambient temperatures AND a cold edge. Once this snowmelt water begins to freeze on the roof edge, the wall of ice or ice dam develops! The ice grows up from the roof edge leaving a homeowner or business thinking they need to melt up as far as the ice has grown. So if the ice dam has grown 5 feet up from a roof edge, the belief is that a system is needed that will heat up from the roof edge 5 feet. Nothing could be further from the truth! Heat cable manufacturers promote this belief because it encourages more heat cable sales! Installers love this belief because they can charge more to install more heat cable and then charge more to maintain it and/or re-install it! When the ice dam becomes thick enough, snowmelt water pools behind the wall and seeks a path of least resistance which is eventually always into your home or business. So, the key is to prevent snowmelt water from re-freezing is to heat the roof edge on a continuous basis! Once this is accomplished, ice dams will not form in most cases.

MYTH #2:
“I should rake the snowpack off my roof and then ice dams will not be a problem”

…FALSE!

The Truth:

Snowpack on your roof acts as a great insulator that enables snow melt water to flow beneath across expansive eave lengths to reach the roof edge where it begins re-freezing. Remember as this understanding is critical; ice dams begin forming where the snow melt water exits the snowpack. The roof edge. If left alone, snowpack ends on the roof edge! This is why the roof edge is the coldest spot on a roof, hence, snowmelt water is allowed to re-freeze and ice dams develop. If snowpack is removed from a roof, then this exposes a roof deck and the potential for ice dams to develop higher up from the roof edge.

MYTH #3:
“Laying heat cable on my roof edge will eliminate the risk of ice dams forming”

…FALSE!

The Truth:

The traditional approach of laying heat cables on a roof edge to prevent ice dams from forming will become an obsolete concept. Our belief is that the heat cable manufacturers came up with the idea as a way to sell more heat cable! In fact, in the springtime, slow migrating snowpack off a roof deck typically tugs at the roof clips that secure heat cable to a roof (voiding the roof warranty!) and leave it hanging off a roof edge until an installer can be paid AGAIN to either re-install it and/or new heat cable would need to be purchased to replace the damaged heat cable. Sounds like a perfect storm for a service-oriented business, doesn’t it? Also, heat tape cables lying on top of a roof deck tend to collect leaves and pine needles. Leaves and pine needles surrounding a heat cable interferes with performance and creates a fire hazard.
In summary, heat cables laying on top of a roof edge can work, but at what expense? To see photos of how heat cables need to lay on a roof edge to be effective, CLICK here. As you can see from the photo, the monthly power consumption to power this concept is prohibitive. To compare the linear feet of heat cable needed to heat a roof edge by laying heat cable on a roof edge versus a concept that is designed to heat a roof edge on a continuous basis, CLICK here.

Myth #4:
“A Properly Ventilated Roof Will Prevent Ice Dams.”

…Mostly False!!

The Truth:

Everyone can agree that proper roof ventilation is beneficial for a home or business. After all, it makes logical sense that the less heat that escapes and reaches the roof deck the colder a roof surface will be and there will be less snowmelt water which means less chance for snowmelt water to re-freeze. What is missing from this discussion is the impact of ambient temperature changes on a roof deck. Two factors cause snowpack to melt on a roof deck; (1) heat escaping from a structure, and (2) ambient temperature changes. So the question becomes, can you control ambient temperature changes with a properly ventilated roof? The answer is simply no. When the sun comes out and is warm enough to heat a roof deck, snowpack will melt regardless of how cold your roof deck is as a result of proper ventilation. The right freeze and thaw cycles as a result of ambient temperature changes will develop hazardous ice dams. Another source of heat which cannot be controlled with proper ventilation is the heat from plumbing and heating vents, chimneys, skylights, and recessed can lighting. Even a properly ventilated attic or roof structure will not vent properly with a few inches of snow covering a ridge vent.

Myth #5:
“I cannot have leaks because my builder installed an Ice and Water shield type membrane on my home to stop leaks as a result of ice on my roof deck”

. . .False!

The Truth:

First of all, properly and perfectly installed membranes cannot prevent ice dam formations. Rather, membranes were designed to prevent leaking as a result of ice dams on a roof. It makes sense, it is like wrapping your roof with a rubber glove. The issue becomes when the membrane is installed. Many factors contribute to membrane failures. They range from improper installation of the membrane or roofing to the slight movements of roofing deck materials. If you can imagine a membrane that is placed on top of nails which were used to secure the plywood to roof rafters. If there is a shift of material over a nail, this is the equivalent of a blister forming on your foot. This problem goes undetected since this area is inaccessible and/or concealed. In addition, the wire used to bind coil gun nails (commonly used by roofing companies to attach shingles) tears the membrane and prohibits a secure seal.