• Roofing

Roof Ventilation: Make Sure Your Roof Vents Properly (Step by Step)

Roof ventilation involves providing airflow in and out of the attic space of a building. Passive ventilation is natural through a roof louver, static vent, edge vents, box vents, baffle ridge vents, and wind turbines. On the other hand, mechanical ventilation involves installing turbine vents, air conditioners, and HVAC units that help circulate airflow in the attic space.

Roof ventilation helps regulate the attic’s floor temperature and prevent moisture buildup creating ice dams, which can lead to mold, rot, and other structural damage. It also enables hot air to escape in the summer and moist air in the winter. Properly ventilated homes maintain the health and longevity of a building’s roof. 

 Here is a step-by-step guide on ensuring proper roof ventilation and avoiding costly repairs. 

Assess the Current Ventilation Situation on the Roof

Assess for signs of poor roof ventilation, such as mold or water stains on the roof vents, led by poor ventilation. You should also look for areas where the top may leak and check the condition of the roofing materials and the attic insulation, as these can also affect the attic’s ventilation.

In addition to visual inspection, measuring the temperature and humidity in the attic is essential. High humidity levels or hot air in the attic can indicate poor ventilation. It is also necessary to check the current roof ventilation system and ensure that the vents are not blocked or covered and are of the right type and size for the attic.

Measure the Attic Space to Determine the Amount of Ventilation Needed

professional measure attic before installing ventilation

The number of roof vents required complements the size of the attic, as a broader attic will require more attic ventilation than a smaller attic. The general rule of thumb for determining the amount of roof ventilation needed is to divide the square footage of the attic by 150. It gives you the square feet of required roof ventilation. 

The minimum requirement for proper attic ventilation is 1 square foot for every 150 square feet of attic space. It’s also important to consider the climate in your area, as different environments will have other ventilation requirements. In addition, also consider the type of insulation and roofing materials used in the attic, as they may affect the ventilation required.

Decide on the Type of Ventilation to Install

When deciding on the type of ventilation to install, it is crucial to consider the specific needs of the attic and the building, such as the size of the attic, climate, insulation, and roofing materials. It’s also important to consult local building codes and regulations, as they may have specific requirements on allowed vents and the ratio of intake vents and exhaust vents.

There are two main types of roof vents to choose from—static vents and power vents. Static vents are passive roof vents that allow air to flow in and out of the attic, helping to cool the attic space and reduce moisture buildup. Their installation is in the soffit or the roof of a house.

On the other hand, power vents use fans to force cool air in and warm air out of the attic, and their installation is on the roof. These vents can either be solar-powered or electric-powered. They can be more efficient than static vents, especially in areas without enough natural airflow.

Check the Ventilation to Ensure It Is Working Properly

After roof vent installation, measuring the temperature and humidity in the attic space before and after installation is vital. It will help you determine if the ventilation is working correctly and if there are any required adjustments.

You must check the balancing of the roof vents by appropriate placement and sizing to ensure an equal airflow of cool air in and warm air out of the attic during roof vent installation. When roof ventilation is balanced, it leads to better airflow and reduced moisture buildup.

It’s also important to check if the roof vents are blocked or covered by debris, which can decrease the efficiency of the roof ventilation system. Regular cleaning of the ducts can ensure that they are functioning correctly.

Routine Inspection of the Vents

The vents are the critical components of the roof ventilation system, and you must regularly inspect them to ensure proper roof ventilation. Check for any signs of damage or wear on the vents, such as cracks, holes, or loose connections that can lead to poor roof ventilation. You should repair any damage as soon as possible to ensure proper ventilation.

professional installs ventilation on chimney

You must also ensure that the roof vents avoid blockage by debris, such as leaves, twigs, or other materials. Keeping the ducts clean and debris-free will secure the roof ventilation system works efficiently. Additionally, it’s essential to check that the vents are securely fastened and properly sealed to prevent drafts, leaks, and other issues.

Ensure Balancing of the Ventilation

In a balanced ventilation system, the amount of intake ventilation (cool air coming in) equals the amount of exhaust ventilation (warm air going out). This balance in constant airflow is essential because it ensures proper attic ventilation with an equal amount of fresh intake air and stale air going out.

The intake vents should be low in the attic, usually in the soffit or near the eaves, while the exhaust vents should be high in the attic, usually in the gable or near the roof’s peak. The size of the vents should be proportional to the size of the attic and match the ratio recommended by building codes in your area.

It’s also important to consider the climate in your area, as different environments will have varying ventilation requirements. For example, hot and humid weather will require more intake ventilation than a cooler and drier climate.

Add Insulation in the Attic

Adding attic insulation in the attic helps reduce heat loss in the winter and increase heat gain in the summer, which can make the ventilation system more efficient. 

Choosing the correct type of attic insulation is essential when adding insulation to the attic. The most common types of insulation used in attics are fiberglass, cellulose, and spray foam. Each type has its own set of advantages and disadvantages, and the kind that is best for your attic will depend on the specific needs of your home and the climate in your area.

When adding attic insulation, ensure that the attic insulation is installed correctly and not blocking the ventilation system. You must check that the attic insulation is not blocking the attic hatch or access door, as this can make it difficult to access the attic for future inspections or repairs.


Attic ventilation is essential to any house, and you must install it correctly. You must also regularly maintain and inspect the roof ventilation systems to ensure proper ventilation. Homeowners can also seek a professional roofing contractor to help them with roof ventilation.

Check Out Our Recent Blog Posts

get the knowledge you need to start your home's transformation

Mother and Son Playing

Transforming Twin Cities Homes

The Voyager family can’t wait to help yours!

Get In Touch
Share to...