In Quebec, winter provides all kinds of challenges to your roof, from freezing rain, to severe temperature changes, to strong winds, to very cold temperatures, to snow accumulation, to rapid ice/thaw cycles. With the climate change that we are all living through, the weather extremes become more pronounced and more frequent. If your roof is not well-designed and well-installed, the weather will find the roof weaknesses, and you WILL have problems.
In winter, the most immediate problems are usually leakage and ice damming. The longer-term dangers are caused by leakage, condensation, and snow accumulation. Sometimes, wind can damage poorly installed flashings or soffits.
If you have leakage, there are a number of possible causes:
- caulking failure,
- flashing failure,
- underlayment or membrane failure,
- failure of waterproofing seals,
- incorrect choice of vents and vent positioning,
- aging of key components that no longer keep the water out,
- fastener seal failure,
- blocked valleys,
- blocked gutters,
- internal condensation
- and other causes that are not as common.
The first step is to figure out why you have a leak when you had none before. As can be seen from the above list, there are many things that can cause an apparent leak. Each possible cause has its own set of diagnostics, and leaping to conclusions usually ends up costing money and doesn’t fix the problem. Finding a leak can be particularly challenging if the roof system was not well built, or if the water has travelled along the vapour barrier.
Ice Dams can appear even with well-built roofs, if the conditions are just right. However, they usually signal a combination of insufficient insulation and ventilation. Older homes, built under codes that were not as stringent as they are now, often have ice dams and massive build-up of icicles decorating the roof eaves. Once the water starts building up behind the ice dam, it is under pressure, and enters any opening, crack, or gap. If the waterproofing is not perfect, you have a leak. If the roof was built with multiple levels of protection, then the water at the ice dams usually stays outside, but if there is only one layer of protection (typical of cheaply-built roofs), then there is no margin of error. Any failure in that one layer will result in a leak.
Occasionally, “leaks” are caused by condensation. How is the moisture getting into the attic or cold spaces in the first place? We find any number of reasons when we start looking for causes – but almost always, it is due to some error in venting, or in a seal that is no longer working. We’ve seen bathroom renovations where the contractor directed the air vent from the bathroom directly into the attic, and more than one case of clothes drier vents being installed with their outlets inside the roof system. We’ve also seen home renos where the potlights were installed in ceilings without the proper sealing, and ended up causing massive amounts of condensation by letting in the air from the living space into the cold spaces.
So, what do you do when you think you have a leak? Call an expert – we’ve seen more of the underlying causes and reasons than you ever will (unless you are really, really unlucky), and we’ll know where to start looking. Depending on what we find, we may be able to fix it quickly, or we may suggest some temporary measures until we can fix it properly once the snow is off the roof in spring-time. Under extreme situations, we can (and have) rebuilt roofs in winter, so it is possible to do, but it can get expensive.
The best way to not have these problems, is to make sure all the fundamentals are working correctly. That means ensuring that your vapour barrier is effective and complete, that you have enough insulation of the right type, that your ventilation is set up in a manner appropriate to your style of home, that there is the right amount of waterproofing (membrane and seals) in all the places where water can appear, and that there is the right layering of protection (membrane, underlayment, flashings, caulking) in all the susceptible areas.
Your home is your most important investment. Shouldn’t you have the best protection for it that you can have?
If you’re not sure you have it, contact us and let us arrange an inspection.
(c) 2013 Paul Grizenko