What You Should Know About Commercial Roof Ventilation

If you plan to replace your commercial roof soon, then you should look into your new roof design and material options. However, you should also look into your roof ventilation system options to decide which may be best for your roof and your building. When your roof is equipped with a proper ventilation system, you can decrease the risk of many roof problems and increase building comfort and energy efficiency.

• Mold growth. Roof materials that become wet due to condensation development become breeding grounds for toxic mold and mildew.
• Wood deck rot. If your roof is equipped with wooden decking or sheathing, then condensation that remains on the wood for long periods of time can gradually rot the wood. Once wood decking rots, it can begin to leak. Extensive roof wood rot can even cause the entire roof to collapse. 
• Heat damage. When the hot air that collects under the interior roof surface increases the temperature of heat-sensitive roof materials, such as asphalt shingles, these materials can break down more quickly, potentially leading to the need for early roof replacement. 
• Higher summer cooling costs.  While a roof ventilation system is no replacement for a cooling system, summer cooling costs can decrease slightly when hot air that accumulates under your roof is released from your building and replaced with slightly cooler outdoor air. 
• Winter ice dams.  When the warm air under your roof interior heats your roof in the winter, snow on top of the roof can melt, then refreeze, creating ice dams. These ice dams can cause water pooling on the roof, and their weight can pose a danger to the roof structure.

• Ridge and eave vent system. Also called a continuous ridge-and-soffit vent system, this simple ventilation system creates airflow under a pitched roof by allowing fresh, outdoor air to enter through vents placed along roof eaves. The fresh air from these vents pushes hot air out of an additional set of vents called ridge vents.
• Static vents. Static vents provide flat roof ventilation. Several static vents are typically placed side-by-side on a flat roof to provide an outlet for hot, indoor air to escape. 
• Mechanical ventilation systems. Also called power vents, mechanical vents have integrated fans that help blow hot, indoor air out from underneath the roof and draw outside air underneath the surface of the roof. These ventilation systems vary in design and are often combined with non-mechanical vent systems to maximize roof ventilation.