How to Improve Roof Ventilation to Prolong Your Home’s Roof

As a homeowner, you want to protect your home and everything inside it. A great place to start is to protect and maintain the health of your roof. When damage happens to the exterior of your home and especially your roof, it can have major repercussions that affect your home and your family. Our Des Moines roofing company wants to help homeowners across Ankeny, West Des Moines, Waukee, and all of Central Iowa prolong the health of their roof, and the best way to do that is by following proper roof ventilation practices.

What is Roofing Ventilation?

Roof ventilation is a system of intake and exhaust vents that provide air circulation to keep the atmosphere inside a home comfortable. Without the in and out passages involved in roof ventilation, hot air will get trapped within your home, causing a variety of problems for your property.

So what’s the best way to improve roof ventilation? The climate you live in and other property factors should be taken into consideration when determining which type of roof vents will provide the most useful functionality.

2 Types of Roofing Ventilation Options

1. Natural Ventilation – Hot air rises within a home and creates pressure in the attic. If this high-pressure air is given an outlet to escape, it will automatically be replaced by cool, low-pressure air. By installing various types of roof vents, homeowners can take advantage of natural air flow to provide proper roof ventilation and keep the inside of the home comfortable. Natural ventilation can also be achieved through doors, windows and other gaps.
2. Mechanical Ventilation – For some structures, it may be necessary to use a system of mechanical vents. This type of roofing ventilation requires a power source to provide constant air flow. Mechanical roofing ventilation options are necessary if the design of the roof doesn’t allow much air flow or the home is in an area without much wind.

Why Is It Important to Have Proper Roofing Ventilation?

Improving your roof ventilation will help keep your roof and the rest of your home in prime condition. If you’re not following proper roofing ventilation tips, warm air will become trapped in your home and cause issues that can lead to costly repairs, which we’ll cover in the signs of poor roof ventilation section.

Maintaining your home’s roofing ventilation is especially important in the Midwest because we experience both extremely cold and hot weather. Roofing ventilation options should protect your home from each of these scenarios:

• Hot air trapped in your home during the summer, making it difficult to keep your home cool
• Trapped hot air causing issues like mold, mildew or ice dams in the winter

Signs of Poor Roof Ventilation

Icicles & Ice Dams – When there’s snow piled up on the roof and you start to notice large ice dams forming along the roof, that means there’s a problem with the roof ventilation. Ice dams form when the roof is heating up, the snow is melting and then the running water is freezing once it reaches the edge of the roof. This is a major indicator of poor roof ventilation and can cause more serious issues. Iowa homeowners in Boone, Fort Dodge, Ames, and throughout North Central Iowa are especially vulnerable to ice dams due to harsh winters. Learn more in our blog about hoA Hot Upstairs and High Cooling Bills – A poorly ventilated attic can get extremely hot in summer. That heat radiates into the rooms below and makes your air conditioner work harder, which raises cooling bills and adds wear to the system.u have ventilation problems.

Roof Leaks, Mold & Mildew – If homeowners ignore the warning signs of poor roof ventilation, it can lead to serious problems later on for your home and your health. When your roof is exposed to water damage over time, or suffered major destruction from a bad storm, this can cause roof leaks. If these are not treated right away, the excess water in the home could create additional problems like mold, mildew and more.

Unwanted Pests Found Inside – Some roof ventilation issues lead to damage to the exterior of your home. If your roof, gutters or siding have been damaged in the past, it could allow critters to find a way inside. Whether you have tiny insects that can creep in through tiny cracks and crevices, or squirrels and rodents that can scratch their way indoors, any of these unwanted pests could be an indicator that there’s an issue with your roof.

How to Improve Roofing Ventilation

If you’re noticing any of the signs of poor roof ventilation above, it’s time to make some changes to improve the roof ventilation in your home. Roof vent installation is an easy task for roofers when replacing a roof since many roofing ventilation options can be installed under the shingles of the roof or mounted outside the roof. There are many different types of roof vents, so we’ll discuss your roofing ventilation options in more detail below.

2 Types of Roofing Ventilation Systems

Exhaust Vents: Allow Hot Air to Escape The Home

Intake Vents: Allow Cool Air to Enter The Attic

How much attic ventilation do you need?

The International Residential Code sets the minimum at 1 square foot of net free vent area for every 150 square feet of attic floor. That can drop to 1 for every 300 when the vents are balanced, with part of the vent area high near the ridge and the rest low at the eaves. For a 1,500-square-foot attic, that works out to about 10 square feet of total vent area at the 1:150 ratio, or 5 square feet at 1:300.

Two rules of thumb we follow on every roof:

• Balance intake and exhaust. Exhaust vents can’t pull air out if there isn’t enough intake letting air in. Too little intake can even pull conditioned air up from the house.
• Don’t mix exhaust types. A ridge vent combined with box vents or a power fan on the same attic can short-circuit the airflow, so one exhaust vent pulls air through another instead of from the soffits.

Benefits of Proper Roof Ventilation

Save Energy Costs – Poor ventilation can lead to rising temperatures in the attic, which spill over to the rest of the home. This leads to high electricity bills, inconsistent heating and cooling within the home and puts more burden on your HVAC units.

Keep Your Home Healthier & More Comfortable – Improper roof ventilation can lead to mold and mildew build up, which can not only damage your roof but pose health risks to your family. Additionally, you won’t have to deal with temperature changes within the home when you follow proper roof ventilation tips.

Prolong The Life of Your Roof – Poor roof ventilation can cause damage and lead to a shorter lifespan for your roof. The top damages include:

• Shingles get very hot and prematurely age when poor roof ventilation keeps the attic too warm.
• Ice dams are a sign of poor roof ventilation, and they cause damage to shingles and eaves. If left untreated, they can even cause roof leaks.
• Moisture buildup from various roof ventilation problems can lead to swelling and rot, which can result in nails not holding and reduced roof capacity.

Proper ventilation is also critical to maintaining your attic insulation — when moisture builds up, insulation loses its effectiveness and your energy costs climb even further.

Schedule a Free Roof & Attic Evaluation

The team at Superstorm Roofing & Siding is passionate about helping homeowners get the most value out of their roof. Make sure you’re following proper roof ventilation tips by getting a drone roof inspection or by scheduling a roof vent installation.

We serve homeowners across Des Moines, Ankeny, Urbandale, Waukee, West Des Moines, Johnston, Grimes, Clive, Altoona, Norwalk, Pella, Winterset, and all of our Iowa service areas. As an Owens Corning Platinum Preferred contractor, our experts will assist you in choosing the best type of roofing ventilation system for your home and ensure proper insulation is in place. If storm damage has already occurred, we can help you understand whether your insurance may cover the repairs. Financing options are also available.

Watch: why your “roof leak” may be a ventilation problem

Roof ventilation FAQ

What are the signs of poor roof ventilation?

Common signs include ice dams and large icicles in winter, frost, damp insulation or mold on the underside of the roof deck, a very hot attic and upstairs in summer, high cooling bills, and shingles that curl or age early.

What is the best type of roof ventilation?

For most Iowa homes, a balanced system of continuous soffit vents for intake and a ridge vent for exhaust works best. It moves air evenly under the whole roof deck without needing electricity.

How much ventilation does an attic need?

The International Residential Code requires at least 1 square foot of net free vent area per 150 square feet of attic floor, or 1 per 300 when vents are balanced between the ridge area and the eaves.

Can you have too much roof ventilation?

Too much exhaust without enough intake is the more common problem. It can pull warm, moist air from the house into the attic. Balance matters more than the total number of vents.

Should I mix ridge vents with box vents or a power fan?

Generally no. Mixing exhaust types on the same attic can short-circuit airflow, so one vent pulls air through another instead of drawing fresh air in from the soffits.

Does roof ventilation help prevent ice dams?

Yes, together with air sealing and insulation. Ventilation keeps the roof deck closer to the outdoor temperature, so snow doesn’t melt on the upper roof and refreeze at the eaves.