How to Protect your Roof From an Ice Dam

You’ve probably heard of ice dams, but do you know what they are and how they’re formed?  When heat form your home escapes into the attic, it warms the surface of your roof even during the coldest winter days.  The heat (combined at times with the heat from the sun) will help melt snow sitting on the roof.  This melting snow runs down into your eaves and then, as it hits the cold metal of your eaves troughs, it freezes once again.  The cycling process of thawing and refreezing creates ice dams, which can result in the water backing under roof shingles or the fascia boards.  The water then has the opportunity to soak through roof decking which means subsequent and at times disastrous damage to attics, ceilings, and even your walls.  Yikes!  An ice dam, when it breaks free, can also pull shingles or even gutters from the roof, adding up to more costly repairs.  It can damage anything it lands on, whether that be your shrubs or trees, vehicles, or even be a danger to people walking underneath.


Obviously no homeowner wants to be faced with a lot of – especially preventable – damage or to put their family and guests at risk of injury.  So how do you go about protecting your home and loved ones  in the first place?  There are 3 main ways, and a combination of all 3 will ensure you’ve prevented the problem.

Insulation.  Your insulation is measured in R-value; the higher the R-value, the better your material is in insulating power.  Insulation keeps heat from escaping into the attic in the first place, helping to prevent the ice and snow from melting and dripping down your roofline into your gutters.  Usually you can easily find the recommended R-value of your insulation geographically, or by asking a professional installer.

Ventilation.  It’s crucial that your home has enough air flow and the ventilation will be a big factor in preventing ice dam.  Ventilation removes heat from the home and doesn’t allow for it to rise and sit in your attic, helping to keep the roof more evenly cool.  If you discover that you don’t have enough ventilation in your roof, it’s a fairly easy process to correct either by yourself if you’re capable, or by a professional.

The third way to help prevent ice dams is to lay a waterproofing underlayment before applying your shingles.  Obviously this is a lot easier to do when your roof is first built or installed, or when the shingles need to be replaced, as otherwise it means tearing the shingles off to install.

If you notice an ice dam forming, you can take some immediate action by hiring a professional or taking a mallet to break it up yourself, although this is only a temporary fix.  In general, the adoption of proper insulation and ventilation will be sufficient to either prevent any or reduce any further damage brought upon by ice dams.