Ice damming will occur when there is snow accumulation on one’s roof and with continual heat loss from inside and/or warmer temperatures on the outside snow begins to melt. The melting saturates the snow along the eaves which then freezes and forms an ice dam during colder temperatures. With continual heat loss from the inside and/or warmer temperatures on the outside the snow will continue or begin to melt. The thaw or water running off the roof is blocked by the ice damm and backs up under the shingles. Ice melting as a result of heat loss through walls can also create standing water which can back up through brick or siding. When the water backs up under shingles and/or siding it will cause water damage to the interior of the home. It will affect insulation, drywall and/or painted surfaces. Ice damming could be the result of poor attic insulation or insulation blocking soffit vents causing minimal ventilation. Other notable problems can be heat loss through improperly installed bathroom exhaust fans, aged or deteriorated roofs or poor design of roof structure.
Ice damming may be unavoidable given our recent weather where we constantly alter between snowy warm temperatures to frigid temperatures (like today’s deepfreeze). However proper construction and maintenance can help avoid serious damage.
- ensure attic is properly insulated with sufficient soffit venting
- ensure that all exhaust fans are properly connected and vented
- heating cables can be installed along the eaves HOWEVER one must remember to turn them on in time to melt the ice/snow build up before damages occur.
Lastly if you are getting the roof shingles replaced talk to a qualified roofer/contractor to ensure that sufficient ice and water shield is installed on the roof before the new shingles are installed. Trying to resolve the ice build up after it has occurred can be dangerous as one could try to break up the ice manually or de-ice the roof. Both can do severe damage to your shingles or roof structure.