| The Facts of Ice Damming |
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If your home has a steep sloped roof, and is more than 20 years old, there is a 98 percent
probability that your attic has excessive heat, leading to ice damming. This can result in
Even newly constructed homes may have serious attic heat problems. Most people attribute
the problem of ice damming to the roof or gutters saying the roofer caused it but this may not
be the case. He may have done everything correctly when installing a roof, and still there
may be ice damming and water leakage- not from unsatisfactory roofer or gutter
workmanship, but rather as a result of one of several subtle sources of heat.
probability that your attic has excessive heat, leading to ice damming. This can result in
Even newly constructed homes may have serious attic heat problems. Most people attribute
the problem of ice damming to the roof or gutters saying the roofer caused it but this may not
be the case. He may have done everything correctly when installing a roof, and still there
may be ice damming and water leakage- not from unsatisfactory roofer or gutter
workmanship, but rather as a result of one of several subtle sources of heat.
Excessive Attic Heat: The Primary Culprit
How does heat enter the attic? How does heat exit in the attic? These are two very important questions that must be asked for
every construction design, whether it is for new construction, additions, or renovations. Without heat, there are no ice dams, no
moisture condensation problems and no health issues. The rule of thumb is that properly ventilated attic air should never be
more than 15 degrees hotter than the outside air. If it is hotter, then that is an indication of additional heat sources that should
be eliminated and/or an indication of unsatisfactory attic ventilation that must be corrected immediately. Snow melt of an attic
without excessive heat build-up and with functional attic ventilation should be totally and uniformly white. If the snow melt were
the result of heat from the sun, all of the roof would be clear, without any white spikes on the roof being present. Attic heat is
the enemy of all roofs, and poses a problem for the insulation, h.v.a.c. systems and health factors, too. Twelve inches of
insulation, creating an R-38, is optimal. Remember, only have one vapor barrier and install it facing toward the heated surface.
If additional layers of insulation are needed to attain 12", use either unfaced insulation or blown-in insulation. Air flow is easily
explained using a ketchup bottle as example. When you open a new bottle of ketchup and turn it over, the ketchup does not
immediately come out. In order for the ketchup to exit the bottle, air must enter the bottle and occupy the space just left by the
ketchup. The same scenario holds true for your attic. In order for heated attic air to exit the attic, make-up air must be able to
enter the attic. Having only inlet vents, or having only outlet vents in a balanced proportion.
How does heat enter the attic? How does heat exit in the attic? These are two very important questions that must be asked for
every construction design, whether it is for new construction, additions, or renovations. Without heat, there are no ice dams, no
moisture condensation problems and no health issues. The rule of thumb is that properly ventilated attic air should never be
more than 15 degrees hotter than the outside air. If it is hotter, then that is an indication of additional heat sources that should
be eliminated and/or an indication of unsatisfactory attic ventilation that must be corrected immediately. Snow melt of an attic
without excessive heat build-up and with functional attic ventilation should be totally and uniformly white. If the snow melt were
the result of heat from the sun, all of the roof would be clear, without any white spikes on the roof being present. Attic heat is
the enemy of all roofs, and poses a problem for the insulation, h.v.a.c. systems and health factors, too. Twelve inches of
insulation, creating an R-38, is optimal. Remember, only have one vapor barrier and install it facing toward the heated surface.
If additional layers of insulation are needed to attain 12", use either unfaced insulation or blown-in insulation. Air flow is easily
explained using a ketchup bottle as example. When you open a new bottle of ketchup and turn it over, the ketchup does not
immediately come out. In order for the ketchup to exit the bottle, air must enter the bottle and occupy the space just left by the
ketchup. The same scenario holds true for your attic. In order for heated attic air to exit the attic, make-up air must be able to
enter the attic. Having only inlet vents, or having only outlet vents in a balanced proportion.
| Ice damming downsides of leaf covers/screens/tunnels |
| During the cold seasons the snow or rain will freeze over top of the cover which will allow build up on the roof & gutter causing ice damming. Any remaining water will flow over top of the gutter causing icicles to form. |
An example of Ice Damming
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