Freezing rain and planning for the unexpected

by Gilbert Migirditsian, professional engineer, home inspector, and founder of GM Inspection

In a winter climate, the weather often goes from warm and pleasant to subzero temperatures in the blink of an eye.  Also, during the past few years, such temperature swings have brought about many other issues such as ice damming, among others.  But can anything be done to prepare for events such as freezing rain, events that we cannot possibly control?  A course of action can definitely be planned but it is not wise to wait until the unexpected happens.  If your property is of a certain age and you are planning to replace the roof, this is the right time to act and prepare for that time when you won’t have time to react.

You may be wondering what exactly is an ice dam and how freezing rain impacts it.  If the local weather is calling for mostly sleet and freezing rain, the sleet can form ice dams on your roof. Remember that you don’t necessarily need snow to be there first and low temperatures for the days preceding the sleet or ice storm combined with low temperatures following the storm make for perfect conditions in forming ice damming on your roof.  Regardless, as extreme weather appears to become more and more common, planning ahead has become more than a recommendation, it is a must.

Remember that you don't necessarily need snow to be there first and low temperatures for the days preceding the sleet or ice storm combined with low temperatures following the storm make for perfect conditions in forming ice damming… Click To Tweet

First and foremost, before installing a new roof, proper ventilation within the attic space is extremely important.  This means not only clearing off the soffits but also ensuring that they are even present in the first place.  I can’t even count the number of situations where I have looked a building with ice damming problems and prematurely worn asphalt shingles where no openings were even present at the soffits.  The presence of perforated soffits is not a guarantee that there is ventilation as I have often encountered cases where this is merely a facade for a solid surface beneath the roofline.  Furthermore, during the planning stage with your contractor, make sure you have sufficient ventilation planned for at this time.  Installing a Maximum type vent is your best bet and having a sufficient amount based on your attic configuration is very important.  I don’t recommend tackling this task yourself unless you have previous confirmation from a licensed professional that the attic is safe to work in.  In many cases, your home may be insulated with vermiculite insulation which is very important to be aware of before beginning work.

Another component to think of is the substrate that your roofing material is to be installed on.  For example, if you are installed asphalt shingles on a sufficiently sloped roof, then the presence of a minimum thickness of 1/2 inch decking in good condition is a must.  Plywood is best but chipboard may also be used.  In terms of thickness, I often recommend to plan for 5/8 inch plywood if budget permits as this will provide you with the best footing to install the asphalt shingles.  Of course, the specific type of roofing you install will determine exactly how your base will be laid.  Don’t forget to plan for an elastomeric membrane to protect your investment.  Of course, if budget permits, completely covering the roof decking with an elastomeric membrane is best.  Again, cost is a trade-off for quality here but every situation is different and the quality of the base you lay beneath your roof will determine how long it will last.

Now what can you do if you do have your roof covered in a sheet of ice?  Here are some recommendations:

  • Keep an eye on the roof to see if the ice is melting on its own. It’s important to remember that if the ice melts and freezes again, the number of times this takes place will increase the risk each time for a leak.
  • If you own a roof rake, then you may carefully try to remove the ice but this must be carried out very carefully as this may do more bad than good.
  • Monitor your attic carefully as the first sign of a leak will begin there and will allow you to act fast before significant damage takes place.

Above all, don’t ever risk your safety in dealing with issues like this, it just isn’t worth it!

See you next time when I’ll be back with more useful information!  In the meantime, visit us on Facebook.