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Ice dams occur on heated buildings with sloping roofs in cold climates with deep snow accumulation. Ice dams on roofs form when accumulated snow forms an insulating layer under cold conditions that would cause the freezing point to be within the snow layer, if it were not subject to melting. Instead,
107:
that create channels for meltwater to escape through any ice dam at the eaves. Heat tapes incur energy expense, may cause long-term damage to asphalt shingles, and may present a risk of fire. Some insurance companies do not allow the use of heat tapes due to the fire danger. Ice dams can also form
111:
Constructing a roof with a slippery surface that is steep enough for snow to slide off, before it can melt. An ice beltâa band of metal roofingâinstalled at the eaves helps prevent the formation of ices dams by placing a low-friction surface where ice dams are likely to form. If an ice dam does
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99:
Providing ventilation under the roofing material that carries escaping building heat elsewhere and assures a cold roof surface. Attic/roof temperatures can be controlled by installing sufficient insulation and providing natural or mechanical ventilation to produce a "cold roof" to keep the roof
35:
is an ice build-up on the eaves of sloped roofs of heated buildings that results from melting snow under a snow pack reaching the eave and freezing there. Freezing at the eave impedes the drainage of meltwater, which adds to the ice dam and causes backup of the meltwater, which may cause water
79:
If any of these factors is absent, ice dams cannot form. Above freezing air does not promote ice dams, nor does granulated spring snow on a roof, which has poor insulating capabilities, nor does a roof that doesn't warm to above freezing at its surface. Ice dams may occur when the under-roof
133:
Removal of snow from a roof with a special tool called a roof rake. To be successful, the entire roof must be shoveled. Shoveling part way up a roof will cause an ice dam to form at the location where the snow was left, because the meltwater will freeze when it hits the freezing
137:
Removal of ice buildup on a roof can be completed by trained professionals that use special steam equipment to ensure quick and safe removal without causing damage to the roof. Mechanical removal with a hammer, chisel or other tools is likely to damage the integrity of the
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57:
where there is no building heat. When the meltwater reaches the frozen surface, ice accumulates, growing a barrier that impedes further passage of meltwater off the roof. Ice dams may result in leaks through the roofing material, possibly resulting in
53:
building heat coming through the roof's surface melts the snow resting on it. This causes meltwater to flow down the roof, until it reaches below a place on the roof's surface that is below freezingâtypically at the
170:, installed under the roofing material helps prevent leakage from ice damming, but has no effect on the formation of ice dams.
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Snow engineering: recent advances and developments: proceedings of the Fourth
International Conference on Snow Engineering
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ceilings, walls, roof structure and insulation, or injury when the ice dam falls off or from attempts to remove ice dams.
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leakage into the roof and consequent damage to the building and its contents if the water leaks through the roof.
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temperature is above 30 °F (â1 °C) and the outdoor air temperature is below 22 °F (â6 °C).
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Gordon Bock, "Frost in the
Rafters, Ice on the Eaves: How to Deal With Winter Moisture".
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placed on the ice dam will lower the freezing point of the ice, thus causing it to melt.
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Assuring integrity of the roof's waterproofing prevents leaks and consequent damage.
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The ice on the wall is from water leaking through the roof due to an ice dam.
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in the roof to prevent freezing at the roof surface under a deep snow pack.
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The melting of roof snow comes from the combination of three basic causes:
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Ice melt socks: A manufactured, permeable material (the sock) filled with
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219:: Trondheim, Norway, 19â21 June 2000. Rotterdam: A.A. Balkema, 2000. 219.
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When an ice dam occurs there are some maintenance options to remove it:
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A thick layer of dry snow, which has good insulating capabilities.
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form, the ice belt may reduce the penetration of standing water.
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Ice dams on sloped roofs can be mitigated in several ways:
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and minimal valleys are effective at shedding snow.
234:, Minnesota Department of Commerce, archived from
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302:. vol. XXI no. 6. NovemberâDecember 1993. 32-34.
75:Heat from the building coming through the roof.
250:"Condensation and Ice Damming on a Metal Roof"
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100:temperature below 30 °F (â1 °C).
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197:. Newtown, CT: Taunton Press, 2005. 54.
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280:. University of Massachusetts Amherst
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195:Roofing, flashing & waterproofing
193:Paul Fisette, "Preventing Ice Dams",
69:Air temperatures well below freezing.
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252:. Absolute Steel. 3 April 2014
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27:Ice dam forming on slate roof.
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727:Short-track speed skating
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108:just above the heat tape.
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276:Fisette, Paul (2011).
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278:"Preventing Ice Dams"
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26:
92:Assuring sufficient
16:For other uses, see
823:Iceman (occupation)
105:heat tape or cables
375:Crystalline phases
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29:
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937:Wikimedia Commons
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300:Old-House Journal
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162:, required by
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732:Tour skating
532:Frost flower
363:Major phases
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284:29 September
282:. Retrieved
256:25 September
254:. Retrieved
244:
236:the original
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32:
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902:Pleistocene
616:Ice-related
527:Frost heave
461:Stalactites
114:Metal roofs
103:Providing
963:Categories
948:Wiktionary
892:Glaciology
847:Other uses
717:Ice racing
712:Ice hockey
687:Iceboating
618:activities
389:Formations
380:Superionic
175:References
118:roof pitch
94:insulation
84:Mitigation
979:Water ice
659:Sculpture
475:Phenomena
40:Mechanism
926:Category
884:Ice ages
838:YakhchÄl
818:Icehouse
644:Climbing
639:Blocking
634:Blasting
552:Hair ice
502:Crystals
231:Ice Dams
143:ice melt
808:Cutting
782:Pykrete
702:Cycling
697:Curling
692:Cricket
664:Skating
654:Rafting
649:Fishing
629:Bathing
572:Nucleus
557:Jacking
536:sea ice
534: (
466:Volcano
430:calving
428: (
426:Iceberg
421:Glacier
166:in the
125:Removal
60:damaged
33:ice dam
18:Ice dam
941:
930:
919:
813:Icebox
772:Palace
757:Bridge
674:Sports
592:Slurry
567:Needle
517:Frazil
436:Icicle
396:Anchor
974:Roofs
864:Cream
854:Chips
833:Trade
767:Igloo
762:Hotel
682:Bandy
607:Storm
597:Slush
587:Shuga
582:Shove
542:Glaze
522:Frost
497:Clear
487:Black
456:Spike
451:Sheet
416:Field
356:water
352:state
349:solid
138:roof.
55:eaves
874:Pack
869:Cube
859:Core
828:Pick
801:Work
792:Road
787:Rink
777:Pier
602:Snow
577:Rime
562:Névé
547:Hail
507:Firn
411:Dune
406:Cave
347:The
286:2014
258:2014
134:air.
752:Bar
512:Fog
446:Sea
441:Jam
401:Cap
354:of
339:Ice
31:An
965::
266:^
202:^
182:^
158:A
538:)
432:)
331:e
324:t
317:v
288:.
260:.
20:.
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