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Ice Dams - Long Island, Nassau County, Suffolk County, Queens, New York (NY)

Ice Dams.

What is an ice dam?|
An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow (water) from draining off the roof. The water that backs up behind the dam can leak into a home and cause damage to walls, ceilings, insulation, and other areas. Figure 1 shows a cross section of a home with an ice dam.
ice dams new york, nassau county, suffolk countyFigures below are a Cross section of a one-and-a-half story house with an ice dam.

What causes ice dams?
There is a complex interaction among the amount of heat loss from a house, snow cover, and outside temperatures that leads to ice dam formation. For ice dams to form there must be snow on the roof, and, at the same time, higher portions of the roof's outside surface must be above 32° F while lower surfaces are below 32°F. For a portion of the roof to be below 32°F, outside temperatures must also be below 32°F. When we say temperatures above or below 32°F, we are talking about average temperature over sustained periods of time.

The snow on a roof surface that is above 32°F will melt. As water flows down the roof it reaches the portion of the roof that is below 32°F and freezes. Voila!—an ice dam.

The dam grows as it is fed by the melting snow above it, but it will limit itself to the portions of the roof that are on the average below 32°F. So the water above backs up behind the ice dam and remains a liquid. This water finds cracks and openings in the exterior roof covering and flows into the attic space. From the attic it could flow into exterior walls or through the ceiling insulation and stain the ceiling finish. ice dams new york, nassau county, suffolk county

Non-uniform roof surface temperatures lead to ice dams.

What causes different roof surface temperatures?
Since most ice dams form at the edge of the roof, there is obviously a heat source warming the roof elsewhere. This heat is primarily coming from the house. In rare instances solar heat gain may cause these temperature differences.

Heat from the house travels to the roof surface in three ways: conduction, convection, and radiation. Conduction is heat energy traveling through a solid. A good example of this is the heating of a cast iron frying pan. The heat moves from the bottom of the pan to the handle by conduction.

If you put your hand above the frying pan, heat will reach it by the other two methods. The air right above the frying pan is heated and rises. The rising air carries heat/energy to your hand. This is heat transfer by convection. In addition, heat is transferred from the hot pan to your hand by electromagnetic waves and this is called radiation. Another example of radiation is to stand outside on a bright sunny day and feel the heat from the sun. This heat is transferred from the sun to you by radiation.

In a house, heat moves through the ceiling and insulation by conduction through the slanted portion of the ceiling (Figure 1). In many homes, there is little space in regions like this for insulation, so it is important to use insulations with high R-value per inch to reduce heat loss by conduction.

The top surface of the insulation is warmer than the other surroundings in the attic. Therefore, the air just above the insulation is heated and rises, carrying heat by convection to the roof. The higher temperatures in the insulation's top surface compared to the roof sheathing transfers heat outward by radiation. These two modes of heat transfer can be reduced by adding insulation. This will make the top surface temperature of the insulation closer to surrounding attic temperatures directly affecting convection and radiation from this surface.

There is another type of convection that transfers heat to the attic space and warms the roof. In the figure above, the winding arrow beginning inside the house and going through the penetration in the ceiling, from the light to the attic space, illustrates heat loss by air leakage. In many homes this is the major mode of heat transfer that leads to the formation of ice dams.

Exhaust systems like those in the kitchen or bathroom that terminate just above the roof may also contribute to snow melting. These exhaust systems may have to be moved or extended in areas of high snow fall.

Other sources of heat in the attic space include chimneys. Frequent use of wood stoves and fireplaces allow heat to be transferred from the chimney into the attic space. Inadequately insulated or leaky duct work in the attic space will also be a source of heat. The same can be said about knee wall spaces.

Photograph 1 shows a single story house with an ice dam. The points of heat loss can be clearly seen as those areas with no snow. The ceiling below this area needs to be examined for air leakage, missing or inadequate insulation, leaky or poorly insulated ductwork, and the termination of a kitchen or bathroom exhaust into the attic space.

ice dams forming
Photograph 1. A single-story house with an ice dam. The areas without snow are the points of heat loss.

Photograph 2 illustrates unusually high heat loss from the roof. There is very little snow left on the roof and at its edge is both an ice dam and a "beautiful" row of icicles.

ice dams
Photograph 2. The unusually high heat loss on this roof has caused both an ice dam and icicles.

So it is primarily heat flowing from the house that is causing the non-uniform temperatures of the roof surface leading to ice dams.

Preventing ice dams
In all New York communities it is possible to find homes that do not have ice dams. Ice dams can be prevented by controlling the heat loss from the home.

Dealing with ice dams
Immediate action:

  • Remove snow from the roof. This eliminates one of the ingredients necessary for the formation of an ice dam. A "roof rake" and push broom can be used to remove snow, but may damage the roofing materials.
     
  • In an emergency situation where water is flowing into the house structure, making channels through the ice dam allows the water behind the dam to drain off the roof. Hosing with tap water on a warm day will do this job. Work upward from the lower edge of the dam. The channel will become ineffective within days and is only a temporary solution to ice dam damage.
Long-term action:
  • Increase the ceiling/roof insulation to cut down on heat loss by conduction. State code requires an R-value of 38 above the ceiling for new homes. In narrow spaces, use insulation products with high R-value (6-7) per inch.
     
  • Make the ceiling air tight so no warm air can flow from the house into the attic space.

Both of these actions will increase the snow load that your roof has to carry because it will no longer melt. Can your roof carry the additional load? If it is built to current codes, there should not be a structural problem. Roofs, like the rest of the home, should have been designed to withstand expected snow loads. In Minnesota, plans showing design details to meet expected snow loads are usually required to receive a building permit. The plans for your home may be on file at your local building inspection office. To help you understand the plans, or if you cannot find plans for your home, you may want to contact an architectural engineering firm. A professional engineer should be able to evaluate the structure of your home and answer your questions about the strength of your roof.

Natural roof ventilation can help maintain uniform roof temperatures, but if the long-term actions described here are done effectively, then only small amounts of roof ventilation are needed to maintain uniform roof surface temperatures. If heat transfer has been reduced substantially, then snow will build up on the roof and cover natural roof ventilation systems, reducing attic ventilation rates. Natural attic ventilation systems are needed to dry the attic space and remove heat buildup during the summer.

Mechanical attic ventilation IS NOT a recommended solution to ice dams in Minnesota. It can create other attic moisture problems and may cause undesirable negative pressure in the home.

WARNING!

  • Any person on the roof during the winter or performing work on the roof from below is risking injury and risking damage to the roof and house. It is important to contact professionals to carry out this job.
     
  • Whenever a house is tightened up, ventilation systems, exhausting devices, and combustion devices must have enough air to operate safely and effectively!

Weatherization contractors, who may be listed under Energy Management and Conservation Consultants or Insulation Contractors in the Yellow Pages, are professionals who can deal with the heat transfer problem that creates ice dams. A blower door test should be used by the contractor you hire to evaluate the air tightness of your ceiling. In addition, they may have an infrared camera that can be used to find places in the ceiling where there is excessive heat loss.

Interior damage should not be repaired until ceilings and walls are dry. In addition, interior repair should be done together with correcting the heat loss problem that created the ice dam(s) or the damage will occur again.

Preventing ice dams in new homes
The proper new construction practices to prevent ice dams begin with following or exceeding the state code requirements for ceiling/roof insulation levels.

The second absolutely necessary practice is to construct a continuous, 100% effective air barrier through the ceiling. There should not be any air leakage from the house into the attic space!

Recessed lights, skylights, complicated roof designs, and heating ducts in the attic will all increase the risk of ice dam formation.

Mold, mildew, and air quality
Moisture entering the home from ice dams can lead to the growth of mold and mildew. These biologicals can cause respiratory problems. It is important that the growth of mold and mildew be prevented. This can be done by immediately drying out portions of the house that are wet or damp. See immediate action steps listed earlier to get rid of the water source. Action needs to be taken to clean the home environment and maintain its air quality.

For more information, contact New Roof Long Island, a professional roofing company..

We have over 30 years of roofing repair experience.  We can fix any of your roofing issues.  Contact New Roof Long Island Today!!

We are partnered with the major roofing material companies and will beat any roofing contractor quotes. Get your price then call us for a free roofing estimate. We travel across Nassau County,     Suffolk County and Queens New York installing new roofs and fixing old leaky roofs.

If you are looking to fix leaks in your current roof or if you want a brand new roof, look no further. We will fix your current roof or do a roof rip and install a new roof usually in 1 day with very minimal mess!  (commercial roofing may be longer)

Article Originally Posted



Nassau County, New York - Roof Leaks, Roof Repair Service, New Roof Installation, We will fix your Roof.

Albertson 11507
Alden Manor 11003
Atlantic Beach 11509
Baldwin 11510
Bayville 11709
Bellerose Village 11001
Bellmore 11710
Bethpage 11714
Brookville 11545
Brookville 11548
Carle Place 11514
Cedarhurst 11516
East Atlantic Beach 11561
East Meadow 11554
East Norwich 11732
East Rockaway 11518
East Williston 11596
Elmont 11003
Far Rockaway 11096
Farmingdale 11735
Farmingdale 11736
Farmingdale 11737
Farmingdale 11774
Floral Park 11001
Floral Park 11002
Floral Park 11003
Franklin Square 11010
Freeport 11520
Garden City 11530
Garden City Park 11040
Glen Cove 11542
Glen Head 11545
Glenwood Landing 11547
Great Neck 11020
Great Neck 11021
Great Neck 11022
Great Neck 11023
Great Neck 11024
Great Neck 11025
Great Neck 11026
Great Neck 11027
Greenvale 11548
Hempstead 11549
Hempstead 11550
Hempstead 11551
Hewlett 11557
Hicksville 11801
Hicksville 11802
Hicksville 11815
Hicksville 11819
Hicksville 11854
Hicksville 11855
Hillside Manor 11040
Inwood 11096
Island Park 11558
Jericho 11753
Jericho 11853
Kings Point 11024
Lake Success 11020
Lawrence 11559
Levittown 11756
Lido Beach 11561
Locust Valley 11560
Long Beach 11561
Lynbrook 11563
Malverne 11565
Manhasset 11030
Manhasset Hills 11040
Massapequa 11758
Massapequa Park 11762
Meacham 11003
Merrick 11566
Mill Neck 11765
Mineola 11501
New Hyde Park 11040
New Hyde Park 11041
New Hyde Park 11042
New Hyde Park 11043
New Hyde Park 11044
New Hyde Park 11099
North Baldwin 11510
North Bellmore 11710
North Hills 11040
North Massapequa 11758
North Merrick 11566
North New Hyde Park 11040
North New Hyde Park 11042
Oceanside 11572
Old Bethpage 11804
Old Brookville 11545
Old Brookville 11548
Old Westbury 11568
Oyster Bay 11771
Plainview 11803
Plandome 11030
Point Lookout 11569
Port Washington 11050
Port Washington 11051
Port Washington 11052
Port Washington 11053
Port Washington 11054
Port Washington 11055
Rockville Centre 11570
Rockville Centre 11571
Rockville Centre 11572
Roosevelt 11575
Roslyn 11576
Roslyn Heights 11577
Sands Point 11050
Sea Cliff 11579
Seaford 11783
South Floral Park 11001
South Hempstead 11550
Stewart Manor 11530
Syosset 11773
Syosset 11791
Uniondale 11553
Uniondale 11555
Uniondale 11556
Upper Brookville 11545
Upper Brookville 11732
Upper Brookville 11771
Valley Stream 11580
Valley Stream 11581
Valley Stream 11582
Wantagh 11793
Wantagh 11568
Wantagh 11590
Wantagh 11594
Wantagh 11595
Wantagh 11597
West Hempstead 11552
Williston Park 11596
Woodbury 11797
Woodmere 11598

Suffolk County, New York - Roof Leaks, Roof Repair Service, New Roof Installation, We will fix your Roof.

Amagansett 11930
Amity Harbor 11701
Amityville 11701
Amityville 11708
Aquebogue 11931
Babylon 11702
Babylon 11703
Babylon 11704
Babylon 11707
Baiting Hollow 11933
Bay Shore 11706
Bayport 11705
Bellport 11713
Blue Point 11715
Bohemia 11716
Brentwood 11717
Bridgehampton 11932
Brightwaters 11718
Brookhaven 11719
Calverton 11933
Captree Island 11702
Center Moriches 11934
Centereach 11720
Centerport 11721
Central Islip 11722
Central Islip 11749
Cherry Grove 11782
Cold Spring Harbor 11724
Commack 11725
Copiague 11726
Coram 11727
Cutchogue 11935
Davis Park 11772
Deer Park 11729
Dix Hills 11746
East Hampton 11937
East Islip 11730
East Marion 11939
East Islip 11730
East Moriches 11940
East Northport 11731
East Patchogue 11772
Eastport 11941
East Quogue 11942
East Setauket 11733
East Yaphank 11967
Edgewood 11717
Elwood 11731
Fair Harbor 11706
Farmingdale 11735
Farmingville 11738
Fire Island Pines 11782
Fishers Island 06390
Flanders 11901
Fort Salonga 11768
Gilgo Beach 11702
Great River 11739
Greenlawn 11740
Greenport 11944
Halesite 11743
Hampton Bays 11946
Hauppauge 11749
Hauppauge 11788
Head of the Harbor 11780
Holbrook 11741
Holtsville 00501
Holtsville 00544
Holtsville 11742
Huntington 11743
Huntington Station 11746
Huntington Station 11747
Huntington Station 11750
Islandia 11749
Islandia 11760
Islip 11751
Islip Terrace 11752
Jamesport 11947
Kings Park 11754
Kismet 11706
Lake Grove 11755
Lake Ronkonkoma 11779
Laurel 11948
Lindenhurst 11757
Lloyd Harbor 11743
Manorville 11949
Mastic 11950
Mastic Beach 11951
Mattituck 11952
Medford 11763
Melville 11747
Melville 11750
Melville 11775
Middle Island 11953
Miller Place 11764
Montauk 11954
Moriches 11955
Mount Sinai 11766
Nesconset 11767
New Suffolk 11956
Nissequogue 11780
North Babylon 11703
Northport 11768
Oak Beach 11702
Oakdale 11769
Oak Island 11702
Ocean Beach 11770
Orient 11957
Patchogue 11772
Peconic 11958
Port Jefferson 11777
Port Jefferson Station 11776
Port Jefferson Station 11777
Quogue 11959
Remsenburg 11960
Ridge 11961
Riverhead 11901
Rocky Point 11778
Ronkonkoma 11749
Ronkonkoma 11779
Sag Harbor 11963
Sagaponack 11962
Saint James 11780
Saltaire 11706
Sayville 11782
Selden 11784
Setauket 11733
Shelter Island 11964
Shelter Island Heights 11965
Shirley 11967
Shoreham 11786
Smith Point 11967
Smithtown 11787
Smithtown 11788
Sound Beach 11789
South Jamesport 11970
South Setauket 11720
Southampton 11968
Southampton 11969
Southold 11971
Speonk 11972
Stony Brook 11790
Stony Brook 11794
Upton 11973
Wading River 11792
Wainscott 11975
Water Mill 11976
West Babylon 11704
West Babylon 11707
West Brentwood 11717
West Gilgo Beach 11702
West Islip 11795
West Sayville 11796
Westhampton 11977
Westhampton Beach 11978
Wheatley Heights 11798
Wyandanch 11798
Yaphank 11980

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