Winters in the Midwest can produce ice dams on roofs.  Ice dams result from snow melting on the roof and can be very serious for several reasons:

   Water can pool up behind the ice dams, which can leak into the attic and drip through ceilings. 

   Melting ice dams can drip onto walking surfaces or steps and make them icy and dangerous.

   Roof coverings and gutters can be damaged by the ice.  Some cases can cause mold to grow in the attic.

   The additional weight of the ice and water can damage the roof structure.

If ice dams are forming along a roof line, it is usually because the attic space is too warm.  There are four common reasons for warm attics:

1.  Insufficient ventilation.  Air flow through the attic should carry the heat out and keep the attic cool.  When ventilation is obstructed, heat can build up in the attic.  The elevated temperatures in the attic cause the snow on the roof to melt and run down the roof.  Even with proper vents installed, the vents can still become obstructed with insulation, debris, bird nests, or are accidentally blocked during remodeling or reroofing.

2.  Air leaks or bypasses between the heated living space and the attic.  Unsealed openings in the ceiling to the attic around recessed light fixtures, speakers, and unsealed scuttle doors will all allow heat to escape into the attic.  Heat rises and will naturally seek out openings in the ceiling.   This loss of heated air will also increase heating costs.

3.  Inadequate insulation.  Most attics are designed to be ventilated with exterior air and should be as cold as the outdoors.  If there is not enough insulation in the attic or in parts of the attic, heat loss from the living space below will cause temperatures to rise in the attic and melt the snow off the roof.  Even if the correct insulation was originally placed in the attic, strong winds, foot traffic, and animals can disrupt the placement of the insulation enough to cause issues.

4.  Leaks from furnace flues, chimneys, vents, or bath fan ducts.  Occasionally, remodeling or reroofing will loosen a furnace flue that allows hot flue gases to discharge into the attic.  Bathroom fan ducts can also become disconnected and discharge warm humid air from the bathroom into the attic.  These leaks can often generate enough moisture in the attic to cause water leakage through the ceilings. 

Why does the ice form?  The melting snow turns to water and runs down the warm roof until it reaches the exterior wall.  Most roofs overhang the exterior wall.  The portion of the roof that overhangs the exterior wall is not insulated and heated so the portion of the roof beyond the exterior walls is colder.  When the water runs down the warmer roof above the attic and past the exterior wall line to the colder area, it freezes.  In some cases, the ice will form in the gutter and build up along the bottom edge of the roof.  

Trying to constantly remove the ice is not recommended.  It is dangerous and can cause damage tot he roof coverings.  The solution is to keep the entire roof cold to minimize the snow melt.  Compare the amount of snow on your roof to neighboring homes.  If your home has ice dams, we can provide an inspection to determine the cause and also suggest ways to help eliminate them.  If ice dams have already caused water damage, our inspection will include a proper repair scope to address the damage.