Why Adequate Roof Ventilation Is Crucial for Monsoon Season

The importance of roof ventilation and how it can prevent damage to a roof when properly protected and installed

Typically, monsoon season in Arizona lasts between the months of June and September. The long-term average rainfall in the state is 5.37 inches for monsoon season, so proper attic ventilation systems are necessary for an Arizona roof. They allow a continual flow of outside air through the attic, protecting the efficiency of the insulation and helping to lower temperatures in the living space. It consists of a balance between air ingress and egress.

It’s crucial for a roof to have an adequate ventilation system to ensure factors like major weather events, especially ones with heavy moisture, don’t take a toll on your roof.

As monsoon season approaches, here are some things to consider:

Measuring your attic ventilation is the first step. The U.S. FHA (Federal Housing Administration) recommends a minimum of at least 1 square foot of attic ventilation (both intake and exhaust) for every 300 square feet of attic space. For example, if your attic is 900 square feet, you need a total of 3 square feet of ventilation. This amount should be divided equally between intake and exhaust ventilation (i.e., 1 1/2 feet of each) to ensure proper air flow through the attic

Moisture control strategies are important to keep in mind for your roof. Be sure a roof includes ventilation and circulation with outdoor air, as they are the major moisture control strategies for attics and crawl spaces. Vapor retarders (vapor-resistant materials or coverings that prevent the transmission of water vapor from moving into building assemblies) reduce the amount of water vapor available for condensation to limit the migration of water vapors from warmer areas to the cold surfaces in walls, roof/ceilings and areas below floors.

Securing your vents is crucial. Loose vent covers can allow rain to blow into the attic. Use a ladder to access the vent and tighten the screws of the vent cover with a screwdriver. Adding a metal sheet, otherwise known as “flashing,” to the seams of your roof cover adds an extra layer of protection as well. Placing a deflector over your roof can keep rain from blowing through the opening.

Existing damage to your roof can result from a poor attic ventilation system and can compound problems. Common damage from a roof without proper attic ventilation includes premature aging of your roofing system (“fried” shingles), warping, cracking or breaking down of the wood frame; damage to siding, exterior or interior paint and wallpaper; roof deck warping and rotting; mildew growth; and buckling shingles and felt.

American Roofing & Waterproofing is an expert in providing you with a roofing ventilation system that will protect your roof for the many more monsoon seasons to come.