This blog was originally published on December 5, 2016 but was updated in September of 2020.
Your roof is a complex system that requires all parts to work cooperatively, and a central component of this system are roofing vents and attic insulation. Today’s wood-framed design and construction techniques of steep-sloped asphalt shingle roofs with an enclosed attic or rafter spaces uses specific design criteria to reduce the likelihood of moisture problems and protect your home from the changing weather in Calgary and Edmonton.
How attic insulation & ventilation works
Ventilation is a system of intake and exhaust that creates a flow of air. Effective attic ventilation provides year-round benefits for all types of roofing systems, creating cooler attics in the summer and drier attics in the winter, protecting against damage to materials and structure, aiding in reducing energy consumption, and helping to prevent ice dams.
Ensuring your attic is properly insulated is an easy way to protect your home and save money on your utility bills – if you’re trying to improve the efficiency of your home, improving your attic insulation can be more cost-effective than replacing doors, windows, or HVAC systems.
Insulation levels are measured through R-value, which tells you the insulation ability to resist heat flow. The higher the R-value, the more effective the insulation, and the more insulation your home has.
What you need to know about roof ventilation
Roof ventilation removes excess heat and moisture in the winter
Good roof ventilation is important in the winter in order to remove all of the heat and moisture which tends to rise into the attic. Activities such as cooking, showering, and doing laundry can release a lot of heat and moisture into the air of a home.
Unvented heat and moisture can cause significant damage
If excess moisture is left to sit in the attic, it will condense on the surfaces underneath the roof. Combined with excess heat, the moisture will encourage the growth of mold, mildew, and rot, causing damage to the roof’s structure that can only be fixed by Edmonton and Calgary roof repair professionals.
In the winter, this condensation can freeze, accumulate, and then melt. This can show either as water entering the home or by saturating insulation, wood, or drywall, causing a wide array of problems such as mold, rot, and degraded insulating conditions. When the weather is cold look into your attic and sees if you can spot any frost or ice buildup, or contact our professional roof repair technicians in Edmonton and Calgary
Poor roof ventilation can cause ice dams
Another issue caused by improper roof ventilation over the winter is the formation of ice dams. Ice dams occur when heat from the attic causes snow to melt while temperatures are freezing outside. The water trickles down the roof and refreezes on the roof’s edge, where it is cooler, forming a dam. The ice dam then creates a pool of standing water which can end up leaking through the roof. If an ice dam builds up enough it can also cause damage to eavestroughs and create large, unsafe icicles overhead.
Proper roof ventilation can improve your home’s energy efficiency in the summer
Roof ventilation is also important in the summer when excess heat trapped in the attic can radiate back out into rooms and living spaces, forcing your air conditioner to work harder. If the hot air is properly vented, then not only will your home be more comfortable but more energy-efficient as well.
Proper ventilation can extend the life of your roof
Your roof is a major investment, and one of the easiest ways to keep that investment safe is to ensure that it has adequate ventilation. By preventing ice dams, moisture damage, and the buildup of excess heat, you’ll help to significantly extend your roof’s lifespan. In fact, having an improperly vented attic space has been clearly shown to impact your roofing materials warranty and its lifespan significantly.
Attic ventilation & asphalt shingle roofs
Most homes are built using asphalt shingles, which protect homes in Edmonton and Calgary against cold temperatures. The amount of ventilation necessary and the type of attic ventilation can vary depending on the roofing system installed and will vary between different homes.
The most common way to provide attic ventilation for asphalt shingle roofs is by passive ventilation, relying on natural air convection – the upward movement of heated air because of its lower density – and wind-generated pressure differences. Natural convection is responsible for initiating the upward flow of air through an attic. Convection-assisted ventilation is most effective when approximately equal amounts of ventilation opening areas are laced at the soffits or eave and at or near the top of the attic space.
Problems with attic insulation & ventilation? Your Edmonton & Calgary roofers are here to help.
A Clark Roofing and Siding LP in Edmonton and Calgary offer a variety of roofing services and repairs necessary to get your home back to its desired look and function. Whether your roof requires additional venting, has developed a leak, or has suffered weather damage like missing shingles or siding, you can count on us for knowledgeable, efficient service.
Overall, proper roof ventilation can play a critical role in preserving the life of the roof and building performance, especially in light of ever-changing weather conditions. If you have questions or concerns about the ventilation in your attic or your attic insulation in Edmonton or Calgary, contact A Clark Roofing and Siding LP at 780.465.7571 today.