ICE DAMS
Preventing Ice Dams
D
id You Know? Ice dams are
caused when melted snow
re-freezes after uneven heat
loss from your home. This
causes the roof to warm above
freezing temperature, allowing snow to
melt and then re-freeze before it reaches
the roof ’s edge. If this cycle repeats
consistently, an ice dam forms and water
collects behind it. Above all, ice dams can
cause expensive water damage.
To prevent the formation of ice dams:
• Keep the attic well ventilated. One-
third square metre of free ventilation
opening is recommended for every 45
square metres of attic space.
• Seal air leaks to prevent warm
air leakage from plumbing vents,
junction boxes from ceiling fixtures
and attic hatches.
• Keep the attic floor well insulated
(between 40 and 56 centimetres of
insulation) to minimize the amount
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of heat rising into the attic from
below.
Clean leaves and other debris from
gutters before the first snow. This
will help prevent ice build-up in your
gutters.
Consider using an ice shield under
your shingles when your house is
getting re-roofed.
Use a roof rake to clear the snow
above the gutter. Clear about one
metre above the gutter to allow
water to drain freely into the gutter.
Consider hiring an energy specialist
to evaluate the performance of your
home and recommend some things
you can do to minimize energy
waste.
SAFETY FIRST
During cold winter months, the icicles
on your home’s eaves may be a sign that
a ridge of ice is forming at the edge of
the roof. This ridge, also known as an
ice dam, can prevent melting snow from
draining properly. If an ice dam forms,
sprinkle a melting compound to break it
up. Avoid using traditional rock salt, as
it may cause further damage and faster
deterioration of your gutters. +
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