The problem occurs when the space inside an attic or the underside of the roof deck is above the freezing point.
Ice problems on roof.
As the warm air beneath the roof heats the shingles and melts the snow on the roof the water flows down the roofline until it reaches the overhanging eave structure where the freezing temperatures cause the water to refreeze.
Here s a breakdown of the conditions that lead to the formation of ice dams.
Effects of ice dams.
Ask this old house general contractor tom silva explains the best ways to keep your roof and gutters free from those dreaded ice dams.
See below for a shopp.
Having a roof rake would help to eliminate the snow.
It will put gutters and downspouts at risk too.
An ice dam is a hump of ice that forms at the edge of a roof under certain wintertime conditions.
This only occurs when part of your roof warms to above 32 degrees f warm enough to melt the snow while the roof edge remains below freezing.
An ice water shield is a critical element to prevent water damage to the edges and valleys of your roof.
Stop ice dams with a cold roof.
The water that backs up behind the dam can leak into a home and cause damage to walls ceilings insulation and other areas.
These dams can tear apart your home so limit them by keeping your roof clear of snow.
Ice dams and icicles form when the snow melts runs down your roof and refreezes near the edge.
Ice dams happen when ice melts trickles down the roof then freezes again.
If dams are a serious threat to your roof the problem is usually due to poor ventilation.
An ice dam can damage both your roof and the inside of your home.
This photo clearly shows how laying heat cable on a roof edge in a zig zag pattern does not work.
I would like you to address all the issues with ice dams and offer sound solutions to those issues.
Finally ice accumulates along the eaves forming a dam.
This scenario is often the result of a warm attic.
Moisture entering the home from ice dams can lead to the growth of mold and.
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.
My point is insulation and air sealing alone don t not stop ice dams they certainly help and save homeowners money yes they do.
As you can see the homeowner was forced to manually rake the roof edge which is a problematic process in itself to temporarily avoid roof ice problems.
Next snow melts on the warm roof and then freezes on the cold eaves.
Thereby elinmating the ice dams.