What You Need to Know About Proper Roof Ventilation

The need for roof ventilation wasn’t documented until the early- to mid-20th century when the American Society of Heating, Refrigerating & Air-Conditioning Engineers recognized that building condensation problems could be caused by poor roof ventilation.

Today, not only is ventilation recommended for your home, it is also required. Proper attic ventilation is important to the protection of your home and your comfort year-round — but especially throughout the cold months as it protects your roof against damaging moisture problems, such as:

• Moisture variations that can warp roof decking
• Mold growth
• Wood rot
• Popped shingles
• Ice dams

According to most building codes, you need one square foot of vent area for each 150 square feet of attic floor space. A balanced ventilation system means about 50 percent of the required ventilating area should be provided by exhaust vents in the upper portion of your attic with the remaining 50 percent provided by intake vents.

Ventilation requirements vary slightly from state to state. The main thing is to make sure you have a place for air to escape your attic as well as a space for air to enter. If the air in your attic sits still, it will condensate and cause serious damage to the shingles, sheathing, insulation and ceilings. Ventilation works best if there is at least as much room for air to enter the attic as there is for it to leave.

There are a few steps you can take to prevent moisture problems in your attic and help maintain proper attic ventilation throughout the winter:

• Seal nail penetrations and around electrical, HVAC, and chimney penetrations to stop free air flow
• If your roof vents have been damaged, replace them.
• Do not cover your attic vents for the winter. Doing so disrupts attic ventilation, leading to moisture issues.
• Make sure the space between the top of insulation and the roof deck’s underside is clear at the eaves. This allows air to move through the rafter space for good ventilation.

Proper roof ventilation extends the life of your roof, reduces energy costs, and reduces indoor temperature extremes.
To ensure your family stays safe and warm all winter long, make sure to schedule a Ventilation Assessment to determine the correct ventilation type for your home. Contact Storm Guard Roofing and Construction of Chantilly to schedule your FREE, no-obligation roof inspection today or call us now at 703-421-7340!