Winter Concerns: Ice Damming, De-Icing Chemicals
Presented by: John T. Stevens, ICS, RS, CGP
Vice President and General Manager, Kipcon Inc.
(732) 220-0200
What I Will Be Talking About…
What is Ice Damming
Symptoms
Results
Causes
Aggravating Factors
Short Term Solutions
Long Term Solutions
What Is Ice Damming?
When a roof is covered
with snow and the outside
temperatures remain at or
below freezing for an
extended period of time,
ice accumulates on the
roof (typically at the eaves
but also in other locations)
and forms “dams.”
Then, when the snow
melts, the water backs up
behind the ice “dams,”
which can penetrate under
the roof shingles and into
the interior of the building.
Symptoms of Ice Damming
Symptoms
Typical Pattern of Snow Melt
on Roof
Icicles Hanging from Eaves
Gutters Clogged with Ice
Ice Damming Symptoms: Typical Pattern of Snow Melt on Roof
Snowmelt refreezes at eaves
Glacier like
Roof shingles and deck can be damaged by
refreezing
Ice Damming Symptoms: Typical Pattern of Snow Melt on Roof
Ice Damming Symptoms: Typical Pattern of Snow Melt on Roof
Ice Damming Symptoms: Typical Pattern of Snow Melt on Roof
Ice Damming Symptoms: Icicles Hanging from Eaves
Indication of
effectiveness of attic
insulation
Icicles are not,
themselves, a problem
Ice Damming Symptoms: Gutters Clogged with Ice
This contributes to
overload of ice at eaves
Interferes with drainage
and aggravates problem.
However, this is not the
cause
Ice Damming Results
Roof/Shingle Damage
Water Penetration into the
Building
Ice Damming Results: Roof/Shingle Damage
Ice Damming Results: Water Penetration Into Building
Results from ice dams
at eaves blocking runoff
of snowmelt
Can penetrate into many
areas (wall cavities;
rafters/trusses, plates,
etc.)
Ice Damming Results: Water Penetration Into Building
The problem is difficult to see until water intrusion into the interior
spaces occurs.
What Causes Ice Damming
Process of Ice Dam Development
Snow/Ice Build Up on Roof
Extended Period of Subfreezing
Temperatures
What Causes Ice Damming: Process of Ice Dam Development
1. Snow fall covers the roof (snow blanket is a good insulator)
2. Warm attic air melts snow
3. Most melting occurs at the ridge because the warmest air is at the
ridge and coldest is at the eaves
4. Snow melt runoff flows under the insulating blanket of snow cover
and refreezes at the eaves, forming dams of ice
5. As more water emerges from the snow blanket, it is blocked by the
ice dams. Water pools on roof and backs up under shingles and
roof deck
What Causes Ice Damming: Process of Ice Dam Development
What Causes Ice Damming: Snow Buildup On Roof
As little as 1”-2” of snow can
cause problems
The deeper the snow, the
more inevitable that ice
damming will occur
Wind blown snow can lessen
or worsen the ice damming
conditions by clearing or
adding snow to different roof
areas
What Causes Ice Damming: Subfreezing Temperatures
Usually takes a minimum of 3-
4 days to develop ice dams
The colder the temperature,
the worse the problem
What Causes Ice Damming: Aggravating Factors
Inadequate Attic Ventilation
Improper Attic Insulation
Poor Construction
Techniques
What Causes Ice Damming: Inadequate Attic Ventilation
The minimum required
ventilation is not sufficient to
prevent ice dams
You can never have too
much ventilation
Ventilation must be looked at
together with improper
insulation
What Causes Ice Damming: Improper Attic Insulation
Typically not enough is installed
(Norm = 6”; Need 10”-12”)
Not installed properly (has
voids, thin spots, missing, etc.)
Uninsulated flue and dryer vent
pipes. Insulation should not
block the soffit vents
Insulation must be looked at
together with inadequate
ventilation
What Causes Ice Damming: Poor Construction Techniques
Not properly securing
insulation blocking vents
Careless placement of
insulation
Lack of attention paid to the
detail of soffits
Short-Term Ice Dam Solutions
Removal of Snow/Ice from Roof
Removal of Gutters
Use of Snow Melt Devices
Use of Snow Breaker
Short-Term Ice Dam Solutions: Removal of Snow/Ice from Roof
Total removal is only effective way of
prevention in a “WARM” house
Partial removal only causes secondary ice
dams to form higher on roof
Removal can cause damage to the
shingles from the tools used and people
walking on the brittle shingles
Going on snow/ice covered roof is
DANGEROUS!!!
Heat cables or tapes accomplish the same
thing as partial removal
Short-Term Ice Dam Solutions: Removal of Gutters
May provide temporary
relief by allowing better
drainage of snow melt
runoff. However, ice dams
still occur on roofs without
gutters
Short-Term Ice Dam Solutions: Use of Snow Melt Devices
Heat cable; different types of
gutters and/or gutter covers, etc.
Many items on the market which
may or may not provide some
level of relief but they only
address the symptoms not the
causes.
Short-Term Ice Dam Solutions: Use of Ice Dam Breaker
1. Fill the leg of discarded pair of panty
hose with a calcium chloride ice melter.
2. Lay the hose onto the roof so it crosses
the ice dam and overhangs the gutter. If
necessary, use a long-handled garden
rake or hoe to push it into position.
3. The calcium chloride will eventually
melt through the snow and ice and
create a channel for water to flow down
into the gutters or off the roof.
Long-Term Ice Dam Solutions:
Install Eave Flashing
Correct Inadequate Attic Ventilation
Ensure Insulation is Properly
Installed
Long-Term Ice Dam Solutions: Install Eave Flashing
Install Eave Flashing
Use membrane (Ice and Water
Shield or other manufacturer)
Membrane has adhesive
backing
that sticks to the roof and wall
sheathing.
It is self sealing and will not
allow
water penetration at fasteners.
Does not address causes; only
prevents water intrusion into
interior space of home.
Long-Term Ice Dam Solutions: Correct Attic and Ventilation
Insulation
Both components must be increased to
obtain a “Cold Roof”
Ventilation must allow for large scale air
movement to quickly get rid of warm air
Insulation must be thicker and more
carefully installed in order to keep heat
loss into the attic to a minimum
Heat generating penetrations into the attic
(flue pipes, dryer vents, etc.) must be
insulated
Special consideration must be given to the
plateline area to make sure it is both well
ventilated and well insulated
Long-Term Ice Dam Solutions: Typical Pattern of Snowmelt on Roof
What I Will Be Talking About
Types of De-icing Chemicals
Application of De-icers
Application of De-Icers
Clear snow prior to application
Apply de-icer in a thin, even layer
Protection of Surfaces
Use chemicals sparingly
Do not use Magnesium in any form
Do not use any de-icer on concrete less than 12
months old
Avoid spreading on plants and lawn
Protection of People and Pets
Keep chemicals away from children and pets
Limit pet’s exposure (wipe paws)
And Now the Short Commercial
Kipcon…
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Thank You!
Any Questions?? John Stevens, ICS, RS, CGP
Vice President & General Manager, Kipcon Inc.
(732) 220-0200
Kipcon Headquarters:
Kipcon Inc. New Jersey
Kipcon Regional Offices:
Kipcon Pennsylvania Fort Washington, Pennsylvania
Kipcon New England Boston, Massachusetts
Kipcon DC Alexandria, Virginia
Kipcon Great Lakes Chicago, Illinois
Kipcon Texas Sugar Land, Texas
Kipcon Inc.
800-828-4118
www.kipcon.com