Big icicles on your roof can be a symptom of a bigger problem: Ice Dams.
…and they can be just as good as a thermal imaging camera for diagnosing this time of year. Have a look at my neighbour’s home below… see how the penetrations into the attic allow heat to escape and cause issues ->
All along most of the eaves we can see that a combination of lack of insulation + air sealing problems add to icicles and that ice dam growing.
What is an Ice Dam?
The root of this issue is warm air escaping from the conditioned part of your home into the unconditioned attic – which is supposed to be cold. (Note: if your home does not have attic spaces because it is a finished space and it has sloped ceilings/cathedral ceilings, we can help you diagnose this too.) This warm air heats the snow at the peak of the roof and the resulting water runs down the roof until it freezes near the frozen edges.
This ice builds up creating a thick ridge of ice and backs up under shingles, into the soffit and on the underside of the sheathing in a cycle of freezing and melting that stresses the shingles, may tear off gutters, and causes moisture damage and mould on the interior.
This diagram clarifies exactly what is going on:
Band-aid fix for Ice Dams
Cleaning the snow off the roof or installing heating cables deals with the symptoms, not the problem – but can prevent the existing problem from causing more problems.
But: be careful! In 2014/15, there were 8,678 emergency department (ED) visits and 1,112 hospitalizations related to falls from ladders for all ages in Ontario. In over 40% of these cases, the injured persons were adults between the ages of 45 and 64. Over 80% of the cases were injured males.
Full Ice Dam Solution.
Exfiltration, ventilation, insulation. (note if you have HVAC ducts in this space they need to be sealed and insulated as well as the other items below)
Seal Attic Penetrations
Sealing up the penetrations means climbing up into your attic space and finding where the warm air from your conditioned space has a crack or gap through which to escape into the cold attic.
When air is escaping through holes and gaps around sill plates, gaps around chimney’s and plumbing or range hood vents, pot lights and other penetrations into your attic, your insulation cannot handle the job. We have even seen vents that should be to the exterior, venting into attic space!
A can of caulking or Great Stuff or other canned foam can help a great deal. It will mean climbing into the attic – carefully! Balance on the studs or you may find yourself downstairs faster than you planned.
Run a bead of caulking or can foam to completely seal cracks and penetrations.
Don’t forget to check the insulation and sealing on the attic hatch.
Ventilate Attic Spaces
Ventilation is another step to dealing with heat and moisture that made its way from your home into your attic. While it may not be within your budget to add roof venting, make sure your existing vents are clear of insulation and obstructions so they can do their job more efficiently.
Ventilation will help keep your entire roof deck cold, preventing melting.
Often the soffit vents are either clogged with insulation or were not real venting to start with – just solid wood!
So soffit baffles will help protect and maintain that ventilation.
Insulate Attic Floor or Top up Existing Attic Insulation
And of course, not having enough insulation in your attic is a key aspect of this issue. If your home was built in 1980 or before, this step alone will make a huge difference.
Insulation should be in a uniform, consistent layer across your full attic deck to a depth of 16″ – 18″. You may see fluffy white, grey or pink insulation or batts up there – or nothing at all. My home had wood shavings – and signs of obvious squirrel nesting. This created bare patches and gave my attic an R-value of just about zero. If you can see the floor joists (studs) – as in this photo at right – you need more insulation.
The good news – often we can top up what you have if it is clean and undamaged and it will contribute to the R-value needed. (R-60 is code right now – that is 18″ of blown in insulation – cellulose ideally).
Need some help with this? We always offer a free-in home assessment and quote to identify the best solution for your home.