Winter Problems Roof Damage
When snow, ice, and freezing rain land on the roof where you live , chances are the coat of frozen stuff will last a while, melting and refreezing several times before finally disappearing. This is not a problem unless your roof overhangs freeze solid , creating an ice dam, which can push water underneath the shingles and cause leaks.
If you can get at the roof edge safely, break off icicles before they become heavy enough to dislodge the gutter . Some homeowners attack ice-choked gutters with a hair dryer or pour hot water in gutters and downspouts to hasten melting. Start at the critical joint between gutters and downspout. Once this area is clear, melting ice will have a drainage channel as you work backward along the rest of the gutter .
Prevent Ice Dams
There are several possible solutions to ice-dam problems. Working from the outside, you can install a strip of sheet metal over the shingles covering the overhang. This method is fairly common in the rural Northeast – it is most effective on steeply sloped roofs, where gravity and the slick metal surface encourage ice and snow to slide off the roof.
Another approach is to install heat cables in a zigzag pattern along the shingles on the overhang. The resistance wiring , which looks like a long extension cord, is attached with small clips tucked under the shingles and even can be extended into gutters to help them remain unfrozen. These cables are designed to produce enough heat to prevent freeze-ups.
Because warmth rising through the ceiling or attic is often the cause of ice dams, you can also alleviate the problem by working. from the inside to reduce the heat flow with extra insulation. In a typically constructed wood frame attic floor, for instance, the spaces between floor joists should be filled with insulation. An additional layer, even the 3 1/2 inch batting used in walls , can be set on top and perpendicular to the joist for more protection. At the same time you can increase the vent size in the attic or crack a window at each end. This will make the bottom of the roof colder and closer to the temperature outdoors, which will prevent melting, while the extra insulation will retard heat flow from living spaces below.
On new construction jobs or reroofing projects, consider installing a rubberized ice shield membrane on the roof deck. It should cover the overhang and at least a few courses of shingles over living spaces. This provides a backup barrier just in case an ice dam does form and works under the shingles.
Usually, theses membrane are made of waterproof, rubberized asphalt and polyethylene in self-adhering sheets that bond directly to the roof deck and to each other at overlaps. The material is installed beneath the shingles, and it seals itself around punctures form nails protruding through the shingles above.