Proper ventilation is key to the lifespan, warranty and function of your new roof.


As part of a roof replacement project, your contractor should thoroughly inspect your home to make sure the roof is properly ventilated. Inadequate attic ventilation can shorten the lifespan of your roof. Without good air circulation, attic temperatures can climb in the summer, and in the winter excessive moisture levels can build up. These conditions can warp sheathing (roof decking boards), and contribute to premature aging of shingles. Many believe that a properly ventilated attic can reduce heating and cooling costs, and reduce the likelihood of mold growth in the home.

It is also important to note that poor attic ventilation can even invalidate the manufacturer’s warranty on your shingles. Attic ventilation requirements are usually stipulated in a roofing system manufacturer’s warranty, and proper ventilation should be documented at the time of roofing installation.


A properly ventilated attic has a continuous flow of outside air. Proper ventilation is based on the principle of convection – hot air rises in the attic and escapes near the peak of the roof, through ridge vents, roof fans or gable vents. As the hot air escapes, cooler outside air is pulled in at the lowest point of the roof, generally through soffit vents located under the eaves (or overhangs). This circulation of attic air helps to minimize excessive heat and moisture in the attic.

Common Roof Ventilation Problems

There are several things that may be obstructing air flow or creating insufficient air intake. Here are a few of the more common issues:

  • No soffit vents, or too few soffit vents to provide adequate air intake: Ideally, soffits should be continuous, running down the entire length of the eave.
  • Obstructed soffit vents: Often layers of paint, debris or insulation inside the eaves impedes good air flow.
  • Improperly installed soffit vent baffles: Soffit baffles are intended to prevent blown attic insulation from blocking soffit vents, but if they are not properly installed, they can actually contribute to the problem by decreasing air intake.
  • Interior exhaust ducts that are venting into the attic space: All exhaust ducts, so as those from bathroom fans or clothes dryers, should be vented to the outside, not into the attic.
  • No (or too few) working power ventilators: Often the homeowner is unaware that a powered ventilator has stopped working.
  • Ridge vents installed with other existing attic vents: For ridge vents to be effective, all other vents should be closed off except for the soffit intakes.


Improving your attic ventilation

During your EXOVATIONS consultation, we will check to make sure your attic is adequately ventilated.

We will:

• Make sure soffit intake vents are free from obstruction.

• Ensure you have enough soffit vents to create adequate air flow.

• Inspect power ventilators to make sure they are working properly.

• Inspect ridge vents for signs that rain is leaking or being sucked in through the ridge vent.

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