Roofing
New Roof Construction: To Vent or Not to Vent?
 
by Clare Kaufman (aka. Sonja Albrecht)
 
To vent or not to vent your new roof? As experienced roofing contractors can tell you, both roofing assemblies have their advantages. Identifying the best style for your home can help you improve the comfort and longevity of your home--and save on home maintenance costs.
 
Scenario #1: Vented Roof
Some roofing contractors recommend vented roofs for cold, damp climates. Other contractors advise all homeowners to vent their new roofing, on the principle that moisture is always an issue and controlling it is ineffective. A new vented roof offers the following benefits:
  • A vent allows moisture to escape, protecting the home's structural features and insulation from mildew and rot
  • By keeping the new roof temperature low, a vent prevents ice dams from forming.
  • Low temperature also increases the lifespan of roof material, reducing or postponing new roofing costs
  • During the warm season, a breezy vented roof keeps the interior of the home cool and lowers A/C use
 
Scenario #2: Unvented Roof
Another school of thought among roofing contractors is that moisture may be controlled, allowing homeowners to take advantage of unvented roof features. Unvented roofing is gaining proponents in response to tests showing their effectiveness. Housing specialist Ralph Britton published a journal article demonstrating that "unvented roof assemblies performed well, showing no excess moisture accumulation."
Advantages of an unvented roof include:
  • Energy savings, energy savings, and energy savings. An unvented roof acts as insulation to the home. Computer modeling studies show that unvented roofs increase the temperature of the underside of the roof sheathing by 10 º to 20º F. This equates to a ten percent reduction in heating load in cold climates
  • Especially in hot, humid climates, unvented roofing keeps moisture out of the home's structure
  • In cold climates, unvented roofing keeps the elements outside, preventing snow or rain damage to the insulation
The decision whether or not to vent your roofing takes many variables into account. In addition to external factors such as climate, roofing contractors evaluate the existing structure of your home. Discuss your options with a roofing company expert to make sure you get the most out of this important investment.
 
About the Author:
Dr. Clare Kaufman is a freelance writer who covers business and education topics.
 
Source(s):
Lstiburek, Joseph     Unventing Attics in Cold Climates     

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