Winter snows can cause lots of damage to your roof. As snow accumulates on the roof, damage can occur in many forms. The first type of damage can occur from the shear weight of the snow sitting on the roof and in the gutters. Not all snow is the same. The water content in heavy wet snow will be much greater than dry light snow. One cubic foot of heavy wet snow can weigh up to 20.81 pounds. That's twelve inches of snow. Keep adding snow, and we can see how quickly the weight can add up. Thirty-two inches of snow on your roof can weigh over fifty-five pounds. Excessive weight can lead to structural failure. It is no wonder that we see roof failures after major snow storms. But these types of structural failures are most often seen on commercial buildings with flat or low sloped roofing. Some of the worst collapses occurred where a winter storm was followed by a heavy rain some days later. The rain simply has no place to go. This happened in Frederick, MD with the collapse of the roof on the Leggett department store after the winter storm of 1997. Signs of structural problems can be seen by bowing roof rafters or sagging roofs. An engineer should be consulted when excessive bowing or sagging is encountered.
A more common type of damage from snow storms is cosmetic damage, including damage to individual shingles or slate, damage to gutters and fascia that has been ripped from the home. As the snow melts each day, some of the water re-freezes at night. As this cycle continues, ice can accumulate in valleys, gutters and at the eaves of the roof.
Picture showing cosmetic storm damage where the gutters and fascia were torn off, and slates were damaged.
This freeze-thaw cycle is the cause of most of the cosmetic damage we see each year. Ice will expand in the gutters and cause seams to fail and the weight can bend and break the brackets holding the gutters to the home. Down spouts can split especially as water freezes in the down spout. As ice builds up in the gutters, down spouts and eaves, there is no where for the melting ice and snow to go. Some of the water will back up under the roofing material and show up inside as a leak. This condition is well known as an ice dam. Unfortunately, while an ice dam is occurring, there really isn't a safe way to stop it. Damage can be minimized if access to the eaves in the attic is easy, but often, the underside edge of the roof is very difficult to reach from inside the attic. In some cases, once all of the snow and ice is gone, there maybe no indication on the roof surface that there was ever a problem. But more often, there will be damage to the roof surface, slate, snow guards, gutters and fascia. At this point, one can plan to minimize future ice dams.
Minimizing Ice Dams:
A more common type of damage from snow storms is cosmetic damage, including damage to individual shingles or slate, damage to gutters and fascia that has been ripped from the home. As the snow melts each day, some of the water re-freezes at night. As this cycle continues, ice can accumulate in valleys, gutters and at the eaves of the roof.
Picture showing cosmetic storm damage where the gutters and fascia were torn off, and slates were damaged.This freeze-thaw cycle is the cause of most of the cosmetic damage we see each year. Ice will expand in the gutters and cause seams to fail and the weight can bend and break the brackets holding the gutters to the home. Down spouts can split especially as water freezes in the down spout. As ice builds up in the gutters, down spouts and eaves, there is no where for the melting ice and snow to go. Some of the water will back up under the roofing material and show up inside as a leak. This condition is well known as an ice dam. Unfortunately, while an ice dam is occurring, there really isn't a safe way to stop it. Damage can be minimized if access to the eaves in the attic is easy, but often, the underside edge of the roof is very difficult to reach from inside the attic. In some cases, once all of the snow and ice is gone, there maybe no indication on the roof surface that there was ever a problem. But more often, there will be damage to the roof surface, slate, snow guards, gutters and fascia. At this point, one can plan to minimize future ice dams.
Minimizing Ice Dams:
- Increase Attic Insulation Above Heated Spaces
- Increase Ventilation in the Eaves including Soffit Vents
- Add a Layer of Ice and Water Shield above the Gutter Line
- Include a Well Thought Out Snow Guard System
- Consider a Snow Melt System
We often try to solve the problem while its happening, meaning we find ourselves or our neighbors climbing onto roofs in very dangerous conditions. Nobody wants water dripping into their homes. I know from personal experience what a disaster it may seem like while the problem is occurring. But I can assure you, drywall, paint, carpeting and other damage is a lot easier to repair than the physical trama that can occur from fall from a ladder or a roof. If water is dripping through your drywall or plaster, take a screwdriver and poke holes near each of the leaks. This will allow the water to flow out and it can then be collected in buckets. More importantly the holes will help prevent the water from accumulating in the ceiling and causing the plaster or sheetrock from collapsing. Of course, shut the breaker off to any light fixture that is leaking water.
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