It may appear odd, but the fact that contemporary homes are better built these days, utilizing superior insulation materials and processes, has resulted in higher condensation creation and heat-trapping if the roof is not properly ventilated. It’s certainly not something you consider frequently, but ventilation in your roofing system is critical and unique to each property. When venting your roof, you must consider factors like climate and roof/ceiling configurations.
Proper ventilation provides for continuous circulation through the underside of your roof, preventing the development of heat, cold, and moisture beneath your roof depending on the season. Because most dwellings are now airtight, they admit very little outside air in. These super-insulated homes are more energy efficient, but because the colder, drier air is kept out, the internal air retains more moisture, causing a number of structural issues.
A contemporary home will have heat build-up and moisture in the attic if suitable attic ventilation systems are not correctly scaled and positioned on a roof to ensure continual airflow. In the warmer summer months, poor ventilation causes heat buildup of up to 60°C on a 30°C summer day. If the ventilation in ceiling is not well-insulated, the heat will linger there for most of the night, gradually finding its way to the home’s interior. An overheated attic mixed with moisture will eventually result in decaying roof decking, damp insulation, scorching, deformation, and shingle curling.
Warm, moist air rises from the ceiling region into the attic throughout the winter, particularly through electrical and plumbing fixtures. This damp air will condense on the chilly rafters and roofing surfaces in the cool attic, dripping onto the insulation, diminishing its efficacy and perhaps leaking through the ceiling below. Condensation can also soak through the attic side of the deck, producing swelling, waviness, and buckling of both the deck and the shingles. Water may eventually damage the roof deck, ruining its load capacity and nail holding power, as many roofing crews have witnessed on numerous roofs. Finally, in the winter, the accumulated attic heat causes the formation of ice dams, which is the melting of snow on a roof even in freezing conditions.
The melting snow then refreezes at the eaves and gutters. This freeze/thaw cycle creates a pool of water beneath roof shingles and behind fascia boards, soaking roof decking and wall sheathing and destroying external and interior walls, resulting in peeling paint and destroyed ceilings. Soaked lumber and construction materials cause wood rot, mildew, and structural property damage. Effective attic ventilation benefits the whole year by keeping attics cooler in the summer and drier in the winter. It’s also worth noting that ventilation alone isn’t a comprehensive answer. It must be utilized in conjunction with a waterproofing shingle underlayment and proper housing insulation.
A well-ventilated attic not only extends the life of your roof but also helps to minimize energy bills. When the outside temperature rises, a properly ventilated roof allows heat to escape, lowering the burden on fans and air conditioners and reducing your overall energy use. It is critical to ventilate a roof properly during installation to avoid difficulties caused by seasonal weather patterns.