Yes, really.
Vented Attic Diagram, from BuildingScience.com
Two of the biggest problems we encounter, deck movement and deterioration, are commonly the results of poor ventilation. In the summer, too much heat builds up due to a poorly-ventilated “flat-ceiling” attic, and causes the shingles and/or deck to deteriorate prematurely. In the winter, deck-related problems are often due to condensation forming on the deck underside, which is also a result of poor ventilation. It’s important to understand that shingles failing before their time – due to inadequate ventilation – will not be protected by the manufacturer’s warranty.
Standard Attics: Ventilation can be very beneficial for roofs over standard attics, especially for those that can be ventilated at both the peak and the soffit. Just last month, Rick Smith, one of our team, was called to the home of Joel F. in Anacortes, WA. It appeared that most of the soffit material (OSB) had gotten a lot of moisture, and had started flaking apart. More often than not, it’s the result of the original contractor doing a poor installation job and installing it wet to begin with. In most cases, poor ventilation doesn’t help, either.
Cathedral Ceilings: Over cathedral ceilings, however, ventilation is more difficult to achieve and heat and condensation problems may occur. Research studying south-facing decks over cathedral-type ceilings has shown that the deck area near the peak does not benefit greatly from ventilation. This area of the roof tends to stay just as hot as an unventilated roof. In general, a roof over a cathedral ceiling will always be hotter than a roof over a ventilated standard attic. To counteract that challenge, vapor retarders, such as plastic foam insulation and aluminum-faced ceiling panels, may be useful.
In short, provide adequate ventilation, especially if you want an unreduced warranty.
Read more about it at: Moisture Problems Attic Ventilation. Then give us a call to see where your attic stands.
Filed under: Decking/Railing, Roofing, Services, attic, deck, moisture, ventilation
