Understanding Ice Dams

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November 10, 2015

How to Avoid Costly Ice Dam Damage

Those gorgeous, sparkling icicles hanging picturesquely from your roof could be hiding a very big headache-to-come: ice dams.

Ice dams wreak havoc on buildings.

They rip gutters from their moorings, loosen asphalt shingles, and warp and rot wood sheathing. The water backed up behind the ice dam leaks into walls and attics creating soggy insulation, dripping ceilings, stained sheetrock, and peeling paint. If not corrected quickly, mold and mildew— and compromised indoor air quality— soon follow.

Ice Dams PhotoIce dams cause millions of dollars of building damage every winter.

What causes ice dams to form?

Heat rises in the building, making the roof warmer than the outside air. The lowest layer of snow begins to melt and drain down the slope of the roof. The overhanging eave of the structure is not warmed by interior heat, so it is much colder. If the outside temperature is below freezing, the thawing water refreezes in the gutter or on the edge of the roof, creating icicles.

Over time, the refreezing water creates layer upon layer over the icicles, building up a dam of ice. The ice dam becomes higher than the water level of melting snow, creating a reservoir of ponding water. The water collects underneath asphalt shingles, buckling up the shingles meant to protect the roof sheathing.

Water begins to seep through the roofing into the structure, damaging walls, ceilings, insulation, and the contents of the home or building.

The deeper the snow, the more likely it is that ice dams will form.

How can you avoid ice dams?

REMOVE SNOW: Keeping the snow from accumulating on the roof is the best way to escape ice dam problems. Use an ice rake to gently and evenly remove snow from the roof, so that one portion of the roof is not supporting more weight than another section. Leave a marginal amount of snow on the roof. Scraping all the way down to the roof’s surface may damage the shingles or roof covering. (CAUTION: Be careful not to brush large amounts of snow down on top of you! Heavy falling snow and debris can result in serious injuries.)Anatomy of an Ice Dam infographicAVOID GUTTERS: In areas prone to heavy snow, consider shunning gutters. Although gutters do not cause ice dams, they do enable the concentration of water and ice along the roofline. If gutters are already present, run heat tape or heating cables though gutters and downspouts to keep the icicles and ice dams from forming. (Check with your insurance company to be sure your coverage allows the use of heat tape or cables.)

HEAT EAVES: Several products are available to heat the eaves where ice dams typically form.

ADD INSULATION: Heat rising to the roof melts the snow. Adding insulation to the roof or attic reduces heat loss, stopping the formation of ice dams. Seal any air leaks that might allow the warm air in the structure to rise to the roof— especially around chimneys, ceiling vents, valleys, and skylights.

INCREASE VENTILATION: Adding small vents in an attic helps keep warm air from gathering underneath the roof. However, if the roof or attic is properly sealed and insulated, vents are unnecessary.

ADD METAL ROOF: Using a low-friction roofing material that better sheds snow eliminates ice dam problems. Snow slides off the structure more easily with metal roofing. (CAUTION: In extreme snow locations, large amounts of sliding snow and ice may be dangerous.)

ICE SOCKS: In a pinch, fill a sock or an old pair of pantyhose with a non-corrosive ice melt. Do NOT use rock salt! Carefully place the sock across the ice dam. (CAUTION: Do NOT attempt to do this on a ladder! Position the sock with a snow rake or broom from the ground.)

Let the professionals do the job of snow and ice removal.

Removing snow and ice dams from the roof can be extremely hazardous. It is best to allow professionals who are better prepared and equipped to handle snow removal safely.

RHINO steel buildings prevent ice dams.

Steel buildings typically do not have eave overhangs, so ice dams are far less likely to form. In addition, the slicker metal roofing on a steel building sheds ice, water, and snow more easily, so it is less prone to form ice dams.

RHINO steel buildings meet or exceed all snow loads and wind loads and building codes (for which the building was designed) for the lifetime of the structure— guaranteed. In addition, RHINO’s extra thick Pro-Value insulation system keeps warm air inside, rather than letting it radiate through the roof.

Phone RHINO Steel Building Systems now, toll free, at 888.320.7466 to learn more.

- by Mat Brown,

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