Let’s be real–your roof ventilation system probably isn’t something you think about very often. At least, not until it breaks

However, it actually plays an important role in the day-to-day life of your home. Having the right amount of ventilation in your attic can have a positive effect on the lifespan of your roof system, the comfort and well-being of your family, your future costs for home repairs and how much you pay for heating and cooling. That’s a long list of benefits for something that is normally just an afterthought! 

That being said, let’s turn some much-deserved attention to ventilation: how it works, why it matters and how to best care for your ventilation system.

How Attic Ventilation Works

Effective ventilation in an unfinished attic usually includes intake vents down low along the soffits, and exhaust vents up high at the peak or roof ridge. This allows for a continuous flow of air through the space. The cooler outdoor air gets pulled in through the soffit vents, and the warm, humid air that migrates to the highest point (hot air rises, cold air falls) exits through the vents along the roof ridge. This creates continuous circulation, which is important for many reasons.

Why Adequate Roof Ventilation is Important

Adequate ventilation up in your attic helps disperse the buildup of excess heat and moisture that can otherwise wreak havoc on your home. Heat and moisture buildup in an attic causes different problems in hot and cold climates; areas with hot summers and cold winters–like most Canadian homeowners experience–can suffer the effects of both.

  • When it’s hot outside, the sun beating down on the roof can increase the temperature in the attic. Exposure to this excessive heat can warp the roof sheathing and distort and prematurely age the shingles. You have to think about the attic floor, too; if it isn’t evenly and properly insulated, all that heat can radiate down into the finished living areas and make it more difficult and costly to keep the living space comfortable. Your AC will be working double-time to keep up, which will show up on your energy bills. 
  • When the temperature drops below freezing during the winter, warm air escaping into the attic from the heated living space below rises to the underside of the roof deck. As the roof deck warms, the bottom layer of accumulated snow on the rooftop begins to melt, causing water to trickle down the roof. As the runoff reaches the cold outer edge, it refreezes into ice. When this happens repeatedly, an ice dam forms along the eaves, blocking the escape of further runoff. Eventually, the water has nowhere to go, so it backs up under the shingles.
  • Let’s talk about the H-word: humidity. Humidity, generated from your living area or from outside, enters your cool attic and condenses into a liquid when it meets colder surfaces. Over time, that moisture can cause deterioration of the roof system and interior structural elements, or ruin the attic insulation. In a warm attic, the moisture will lead to the flourishing of the dreaded mould and mildew. This, in turn, puts added strain on the home’s cooling equipment. Your wallet suffers…again.

Signs of Improper Ventilation

An inadequate attic ventilation system can cause issues that manifest themselves in different ways:

  • An unexplained increase in your household heating and cooling bills, which can happen if your attic insulation gets wet and loses its effectiveness.
  • A noticeable buildup of ice along your roof’s edge during the winter months.
  • A wavy or curved roofline and rippled shingles caused by the warping of moisture-damaged decking underneath.
  • Rust and corrosion on metal materials in the attic, such as nail heads, electrical boxes or light fixtures.
  • Dampness, water stains or frost on the attic side of your roof sheathing.
  • An increase in allergy symptoms or respiratory illnesses among your family members, often related to the spread of mould growth in your attic.

What to Do

If you see warning signs, like the ones mentioned above, or are worried, it’s wise to have your attic inspected by a certified roofing contractor who can assess whether there’s enough ventilation or if your system needs to be replaced or repaired. They can advise you on what options exist to improve ventilation and make sure it’s effective. 

If you have questions or concerns about your current ventilation setup, No Payne Roofing can help you out. Our certified roofing contractors can evaluate your ventilation needs and get the project done quickly and efficiently, so your home can get the air circulation it needs. Call us to discuss your needs and how our team can help.