Roof Ventilation: Why It's Important & 5 Keys To Proper Ventilation

Roof ventilation - nothing brings up more theories, practices, and ideas among roofers than the topic of roof ventilation!

With many different opinions about ventilating a roof, it can become easy to ignore the importance of proper ventilation and simply rely on installing several gable vents to do the job.

However, this can result in long-term problems in the roof and attic - mold, ice dams, callbacks, and a damaged reputation as a roofing contractor.

At SnapZ we want to help you understand why proper roof ventilation is essential and five keys to vent any roof properly.

Are you ready to become the trusted roofing expert in your area when it comes to ventilation?

Let’s get started!

Table of Contents

  • 1. Why Is Proper Roof Ventilation Important?
  • 2. Five Keys to Vent Any Roof Properly
  • 3. How Does SnapZ Help Roof Ventilation?

Why Is Proper Roof Ventilation Important?

When discussing roof ventilation, we need to start by recognizing that proper ventilation is essential in any climate: warm, cold, or mixed.

Some may argue ventilation is only necessary in a warm or hot climate, but this is false!

Let’s take a look at why venting a roof is necessary for any climate (scroll to the bottom of this section for a handy infographic).

Why ventilate roofs in warm climates?

First, ventilation is critical to remove the warm air in the attic. A solar-heated roof heats the attic air, and this air should be removed to reduce moisture and improve cooling efficiency.

Second, you need to remove moisture from the attic with ventilation. Leaks, storms, and improper roof vents introduce moisture into an attic. If the attic isn’t properly vented, this moisture causes long-term mold and structural damages.

Third, you help save the owners money on their cooling bills! It doesn’t matter if they are a home or business; proper ventilation brings cooler air into the attic and puts less strain on the air conditioning.

Why ventilate roofs in cool climates?

First, proper ventilating is critical to reducing ice dams on the roof. If warm air collects in the attic from the conditioned area below, this warms the roof and melts snow and ice.

The result of snow and ice melting on the roof?

It refreezes when the sun goes down, and you quickly have a vicious cycle of ice dams on the roof.

Second, it makes roofs safer during the winter. Ice dams pose a safety hazard when they result in large sheets of ice collecting above walkways, driveways, and other traffic areas.

Third, removing moisture and the potential for mold is critical in any climate, including cool climates. While roofs should keep moisture out of the attic, you need proper ventilation to make sure any moisture is quickly removed.

What about roof ventilation in mixed climates?

Most of the Central and Northeastern United States falls into a “mixed climate” category. Proper ventilation in a mixed climate helps avoid the problems of the warmer and cooler weather - ice dams, moisture in the attic, and higher heating bills.

P.S.  Want to learn how quality ridge vent can help you ventilate? Check out our blog: 5 Ways a Quality Standing Seam Ridge Vent Helps Contractors Win

ridge roof vent is important in ventilation

5 Keys To Vent Any Roof Properly

If you want to become the trusted roofer in your area who knows how to vent a roof, then start by following these five keys (scroll to the bottom of this section for a handy infographic):

1 - Completely seal the attic floor

This is the core of proper roof ventilation - keep adequate insulation between the attic floor and conditioned living areas.

Having a “Swiss cheese” ceiling with multiple punctures and holes is an invitation for warm and humid air to enter the attic. It is critical to have everything properly sealed and insulated.

2 - Maximize insulation above the roof’s top plate

The insulation above the roof’s top plate should be equal to or greater than the wall’s thermal resistance.

Begin by finding the R-value of the wall, and then make sure the top plate insulation is equal to this or greater.

3 - Continuously vent the soffit

The building’s soffit location is important in the roof’s design. As the sun hits the building’s side, a larger concentration of solar-heated air gathers along the structure’s side and begins to rise.

To allow this warm air to escape, the soffit should be placed as far away from the building’s structure as possible and remain open.

4 - Have adequate space in the roof

Most building codes require a minimum of 1” space between the roof sheathing and insulation. However, because this space regulates how much air enters the attic, many experts agree this space should be larger.

In colder climates, the recommended airflow is a 2” space instead of the minimum 1”. As with any building project, you should first confirm this larger space is OK with your local building code.

5 - Slightly pressurize the attic

Many builders default to having the intake and exhaust vents equal in size when installing attic ventilation.

However, if the eaves have slightly more pressure than the ridge, then the attic air moves through the attic more efficiently.

To achieve ideal attic pressure, the open-space ratio between the eaves and ridge should be around 60/40.

5 techniques for proper attic ventilation

How Does SnapZ Help Roof Ventilation?

When it comes to proper metal roof ventilation, there is always a concern about having vents that are too large on the roof.

Why are large vents a problem?

The larger the vent, the more chance you have for rain, bats, birds, and other critters to enter the attic.

SnapZ’s standing seam metal ridge roof vent helps solve these problems - our metal ridge vent is designed to be completely water-proof, critter-proof, and efficient.

Our roof vent is also shipped pre-cut and pre-drilled to minimize installation time and maximize your crew’s efficiency and job profitability!

Read more on our blog about how SnapZ stops critters, why it makes you a trusted roofing contractor in your area, or why we recommend going with one color vent - black!

Contact us to receive a free sample and learn more why the SnapZ roof vent is the vent you need for your next standing seam metal roofing project!

Ridge roof vent


  1. Homeowner on September 10, 2022 at 10:08 am

    You say calculate a 60% air opening in eaves to a 40% air opening in ridge vent but you don’t say what the equivalent opening is for the snap-Z 15″ section that is installed between the ridges. What would it be for a 1″ standing seam nail strip striated panel? Same question for all heights. This should be published. Please forgive me if it is and I just could not find it.

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