Weather conditions must be just right for ice dams to occur, but when they do they are potentially destructive to your roof system. Ice damns can cause gutters to give way, can damage shingles and cause interior leaking. The time to prepare for ice dams is in the summer or fall, before the onset of winter weather. An ice dam is created when heat rising from the interior of your home collects in the attic, warming the underside of the roof decking, except at the eave area, and begins melting the snow. The meltwater runs down the slope of the roof, only to refreeze at the colder overhang. Subsequent runoff, having no place to drain, backs up under the shingle and into the interior of the home. Staining is often found in the interior of the home on the ceiling and near exterior walls. First line of defense is a properly insulated and vented attic. Read up on how by clicking here. Then keep your gutters clear and if necessary purchase a roof rake for excessive snow removal.
Icicles are harmless, right? Wrong. They simply result from the same conditions that cause ice dams. They can damage your roof system , destroy gutters, not to mention, cause injury to people if they fall. Once icicles are present, there is a danger of a dam forming as melting snow runs down the roof and then refreezes at the cold edge. Again, it's time to address your attic insulation. You'll also want to stop air leaking through recessed lights, leaky heating ducts, attic access doors, and plumbing and electrical penetrations. A sure sign that something is awry in your attic is uneven snow melting on your roof, as areas with inadequate insulation have more heat loss and melt much more quickly. So observe your roof closely and remedy right away.
If your roof has icicles, ice dams, or both, chances are you may be dealing with condensation issues as well. The same factors that cause ice buildup on roof edges also cause attic condensation problems. The first step in managing attic moisture problems is to have proper ventilation and manage moisture within the conditioned/living space in your home. Being sure that dryers, and heating equipment/fireplace are properly vented, and that things like dehumidifiers, plumbing leaks, or stored wood, for example, are not causing excess moisture to build up in your home is a first step toward addressing the problem. The last culprit for condensation is air leakage from the condition spaces of the home into the attic. Beyond installing proper insulation and monitoring that appliances and bathrooms/kitchens are properly vented, most homeowners to not posses the tools or expertise to properly find and address all air leaks in the home. For this final step, it is recommended to seek a professional's help.
Excessive Snow Loads
Your roof is designed to withstand snow loads, especially structures in northern climates. Keep in mind that ice weighs significantly more than heavy, wet snow per inch depth. So this makes it all the more important to remedy the issues mentioned above and prevent ice buildup on a roof structure. Most structures are not in danger of snow induced failure, but excessive loads can still be an issue in unique circumstances. According to the FEMA Snow Load Safety Guide, Structural failure due to roof snow loads may be linked to several possible causes, including but not limited to: snow that significantly exceeds the load for which the roof was designed to withstand, excessive snow drifting, deficient workmanship, and inadequate drainage. And again, according to FEMA, the following are signs of over-stress conditions during a snow event:
- Sagging ceiling tiles or boards, ceiling boards falling out of the ceiling grid, and/or sagging sprinkler lines and sprinkler heads
- Sprinkler heads deflecting below suspended ceilings
- Popping, cracking, and creaking noises
- Sagging roof members, including metal decking or plywood sheathing
- Bowing truss bottom chords or web members
- Doors and/or windows that can no longer be opened or closed
- Cracked or split wood members
- Cracks in walls or masonry
- Severe roof leaks
- Excessive accumulation of water at nondrainage locations on low slope roofs
If any of the above conditions exist, seek the help of a professional structural engineer to conduct a detailed inspection immediately.
Other Roof Problems
Typical roof issues that homeowners can experience any time of year can be made worse by snow and the constant freezing and thawing of winter. These include: flashing or chimney repairs, gutter issues, damaged or missing shingles, or a roof in need of replacement. MOST roofs can in fact be replaced no matter what the time of year. If it is necessary, it should be done! Interior damages that can result from a failing roof that is left all winter could be very costly. When in doubt, call a professional.