Leaky ceilings are not cool. Everybody knows that. You may not know that it's not your roofer's fault. Your roof was never intended to be submerged in water. That is what an ice dam does to your roof. Ice dams are indicators of a few things going wrong in your attic system. The illustration below shows how warm air leaving your house melts snow on your roof that re-freezes, creating a dam. It's quite sad.
Here are four things you can do, or hire some reputable fellas to do for you, to prevent ice dams from ruining your day.
1) Increase attic airflow with soffit vents and roof vents. (It's not what people tend to think of first so I listed it first.) Be sure your attic has proper ventilation so the warm air can be carried away from your roof deck out your attic vents. That keeps your roof deck cool and your snow frozen. You need high vents (on the top of the roof) and low vents (soffit vents) to have proper air movement.
2) Increase air flow by adding attic rafter spacers against your roof deck. This ensures there is space along your roof deck for air to move. It is especially important where your rafters meet the attic floor for that is where your insulation will tend to pile up to your roof deck and stop air flow. Heat will inevitably wiggle its way through your insulation. If there is no space for that heat to be carried away it will wiggle though your decking and your shingles until it mingles with the snow.
3) Add attic insulation. Prevent heat loss by insulating better. Expect to pay about $1 a square foot for blown in insulation.
4) Prevent air leakage by spray foaming leakage points. As hot air rises it creates a pressurized field. It pushes on your ceiling trying to bust out. Attic accesses, light fixtures, plumbing stacks are all gateways to your attic that the sneaky warm air molecules escape through. Make an airtight barrier and trap those molecules in with spray foam, three cans will probably suffice for the average rambler. Also, caulk shut your attic access - from the outside.
Lastly, your homeowners insurance may not pay to fix systematic problems but they will likely repair ice dam damage to your ceiling, walls, floor, insulation, etc. Most of the time they pay for the ice dam removal as well, if it is attached to a claim.
We hope this helps.
Talk to you later.
Andy Higgins
612-232-6658