If parts of your roof are warmer than 32 degrees F but others are still below freezing, snow may melt and cause water to trickle towards the edge of the roof before refreezing and forming an ice dam. Ice dams, which are often marked by multiple large icicles, can cause a lot of roof damage by working their way under shingles and forcing gutters out of place. Luckily, they are almost always caused by one of these structural problems, all of which are relatively easy to fix.
Inadequate Attic Insulation
In cold climates, homes should have two layers of R-49 fiberglass insulation in the attic. Any less than this, and heat from your home will likely seep into the attic, causing ice dams to form. The first layer should be placed between the ceiling joists, and the second layer should be placed perpendicular to the joists.
If you have only one layer of insulation in your attic, adding an additional layer is a project you can tackle on your own. Make sure you wear a long-sleeved shirt, eye protection and a dust mask to protect yourself from the fiberglass.
Inadequate Roof Ventilation
If your attic appears to be well-insulated but you still have ice dams on your roof, poor roof ventilation may be to blame. If your roof is not well ventilated, warm air may build up inside your attic with no way of escaping. Call a local roofing company, like Gulfside Roofing Inc, and have them make sure your ridge vent and soffit vents are open and clear. It the vents are blocked or have not been installed properly, this situation can generally be fixed within a few hours by an experienced roofing team.
Heat Sources in the Attic
If your home has a heat source such as a boiler or hot water heater in the attic, then this arrangement is likely to blame for the formation of ice dams. Rarely are these appliances placed in attics in new homes, but if you live in an older home that was not designed by a professional architect or builder, you may find yourself in this situation.
In some cases, this problem is easy to solve. The appliance can simply be moved to the basement or first floor and a small amount of re-wiring and re-piping later, your attic will be cooler. In other cases, moving a hot water heater or furnace from the attic to the basement requires re-plumbing or re-wiring the entire home. Call a local plumber or HVAC specialist for an estimate to determine whether moving the appliance is worth the effort and cost.
Especially if you have a new roof, ice dams are not a problem you should ignore. Start investigating to see which of these factors is to blame for your home's ice dams, and take action to prevent future ones from forming.