Do Low-Slope Roofs Require Ventilation?

Roof Ventilation Requirements for Flat Roofs

When it comes to roofing, ventilation is incredibly important. Having a properly ventilated roof helps protect your roof from the damaging effects of superheating. Extreme heat can cause roofing materials to degrade and disintegrate, threatening the integrity of the roof and its ability to protect your home effectively. But how do you vent a low-slope or flat roof?

Types of roof ventilation that can be used in low-slope roofs:

  • Gable vents
  • Fascia vents
  • Turbine vents
  • Soffit vents
  • Ridge vents

How to ventilate a low-slope roof will depend on just how sloped the roof actually is. If you have some slope to the roof, you may have gable vents installed on opposite sides to encourage a cross flow. Fascia vents can also be used to provide venting in low-slope homes. Finally, turbine vents are another good option for low-slope or flat roofs. These vents have a fan that helps pull hot air out of the roof.

Review our blog, “Understanding Roof Pitch,” to learn more about roof pitch and why it matters.

Intake vs. Exhaust Vents

When venting a roof, regardless of slope, you need both intake and exhaust vents. Essentially, fresh air enters the crawlspace, attic, or through the intake vent, usually through a soffit vent. Soffit vents are located near the home’s eaves, low on the roof. Meanwhile, the hot air you want to vent escapes through the exhaust vent, which is typically installed at the highest point of the roof. When working correctly, these two vents work together to create air circulation through passive venting.

What About Homes That Don’t Have Attics or Crawlspaces?

Many homes have vaulted ceilings without an attic space. Homes without attics or crawlspaces are surprisingly common, including in low-slope or flat-roof homes. However, just because there is no attic space doesn’t mean you don’t need ventilation. In these situations, roof ventilation and air circulation are still crucial to keeping your roofing dry and not too hot.

Typically homes that do not have attics or crawlspaces still have rafter cavities. These cavities are where intake and exhaust vents will be installed.

Signs You Need Better Roof Ventilation

If you have a low-slope or flat roof, you may wonder if it is ventilated enough. Most roofs have adequate passive venting. But, living here in Arizona, with extremely high temperatures for much of the year, it is sometimes necessary to boost your existing roof ventilation with additional venting or by installing a solar attic fan.

Four signs you may need better roof ventilation:

  • You are having moisture problems
  • Your roofing materials are degrading much faster than they should be
  • You have a hard time keeping your home cool in the summer
  • Your energy bills are higher than they should be

Diagnosing a roof ventilation problem with a low-slope or flat roof is difficult without the help of a professional roofer. If you are struggling with roof issues related to ventilation and superheating, your best bet is to schedule an appointment with one of our roof ventilation specialists.

Have more questions about roof ventilation? Reach out to the experts at Lyons Roofing today. Our team is always happy to help, and we can answer any questions you have about roof ventilation for flat and low-slope roofing.