Everything You Need to Know About Attic and Roof Ventilation

We all understand the importance of a healthy roof for keeping a home in great condition. But what’s one often overlooked area that plays a huge role in a roof’s performance and efficiency? Ventilation. Here, we’ll go over how to determine whether you need better roof and attic ventilation.

Why is Good Ventilation So Important?

When we refer to roof ventilation, we’re not talking about anything complicated or mysterious. We still mean airflow, or circulation. Roof ventilation requires consistent airflow to function properly. This is typically achieved mechanically, through a power source, or naturally, using the stack effect or the wind effect.

The stack effect occurs when hot air rises and creates pressure in the attic. In order to avoid growing too hot, the hot air, known as exhaust, needs a means for escaping through the roof. Exhaust cannot escape an attic without cool, lower-pressure air entering the attic, air known as intake. Exhaust and intake work together to keep airflow steady and create a well-ventilated attic. If this circulatory system isn’t adequate, your roof could experience a number of problems.

Attic Ventilation: Telltale Signs You Need More

Ice dams

Ice buildup on a roof is known as ice damming. The presence of icicles hanging from the gutters of a home is a huge sign that its roof is not ventilating properly. Ice dams form when a roof gets too hot. Heat builds up in the attic, except in the eaves. This heat radiating through the roof causes snow to melt and begin to run off, and because the eaves are still cold, the snow freezes and turns into icicles at the gutters. But the issues don’t end there. The melted snow can back up as ice accumulates, flowing under the shingles, destroying your roof and even potentially leaking into your home.

We should also note that icicles present a very real hazard of their own. Larger icicles can cause serious injury once they loosen and begin to fall, and the weight of accumulated ice can cause gutters and awnings to collapse. All the more reason to install proper roof ventilation!

Your HVAC system is working overtime

If your HVAC system is suddenly having to pull double-duty to heat or cool your home, poor ventilation in the attic could be to blame. Exceptionally hot air in the attic can hinder your thermostat’s ability to regulate the temperature in the rest of your home. To find out if poor ventilation might be to blame, place a thermometer in your attic and monitor the temperature.

Mold is forming in the attic

Ventilation doesn’t just control temperature, it also helps control moisture. If you notice mold forming on the ceiling joints, rafters and beams of your attic, you’re probably in need of a ventilation overhaul. You’ll likely need to hire a professional to remove the mold before tackling the ventilation issue. Since inhaling mold spores can be dangerous, we don’t recommend undertaking the task yourself.

You’re noticing rust

Rust is another major indictor of moisture issues in the attic. Are you noticing those telltale brown stains on your roof’s metal components? You’ll need to hire a roofer to determine whether poor ventilation could be to blame (it probably is!).

Types of Attic Ventilation

With so many different options for ventilation, you’ll want to seek a professional opinion for advice on getting the best system for your roof’s size, age and condition. Here are several of the different ventilation devices you can choose from:

Box vents

Box vents, also known as low profile vents, louvers, flat vents or turtle vents, are static and have no moving parts. Because they are relatively small, numerous box vents are typically required to properly vent a roof. They are made of either metal or durable plastic and installed over holes cut in the roof to allow for an adequate amount of heat and moisture to escape.

Power vents

Power vents run on motors that help turn large fans to move exhaust and moisture out of the attic. Some even come with “smart” thermostats that trigger a fan to kick in when the attic reaches a certain temperature. Some are also equipped with a humidistat to kick on when humidity levels get too high. Most power vents are hardwired into a home’s electrical, but you can also find models that run on solar power. One con of power vents is that they run so quietly, it can be difficult to detect when one goes out, leaving your attic and roof at risk.

Wind turbines

Also known as whirlybirds, wind turbines rely on wind power for movement. The bulbous piece, similar in shape to a chef’s hat, spins in the wind, drawing hot air and moisture up and out of the attic. Wind turbines can be tricky—you definitely don’t want to go the inexpensive route here. Instead, opt for high-quality models with plastic bushings and permanently lubricated ball bearings.

Soffit vents

Most often composed of PVC or aluminum, soffit vents are placed in soffits and eaves. Soffit vents are not solely relied on for proper ventilation, but when combined with other types of vents, they’re an excellent option. Many homeowners choose to install them when they would like to boost ventilation and efficiency while still keeping their original system in place.

Ridge vents

Ridge vents are shaped like an open book laying facedown. Running with this analogy, the spine area of the “book,” or vent, is fitted over the entire length of the roof’s horizontal ridge to create an even distribution of temperature in the attic. Ridge vents blend more seamlessly with a home’s roof than most other types of ventilation systems, and are considered an attractive option. When combined with soffit vents, they’re also considered one of the most effective solutions out there.

Off ridge vents

Off ridge vents function similarly to box vents, but rather than being square, they’re rectangular. Because they’re small and static, you’ll need to install several of them on your roof to achieve adequate airflow.

Cupola vents

More often than not, cupola vents are decorative in nature, resembling miniature gazebos and sometimes housing weathervanes. Cupolas can, however, be functional, allowing hot air and moisture to escape from the roof. It should be noted that this type of ventilation is limited in its capabilities and should probably be combined with another type of system for the best results.

Call National Property Inspections Today for an Assessment of Your Roof

National Property Inspections can examine your home’s attic and roof and determine whether you are dealing with poor ventilation. Give us a call today to receive a full report complete with digital photos.

Do I Need a New Roof? Here’s How to Tell

If you’ve asked yourself the question, “Do I need a new roof?” you might be wondering exactly how you can tell. Since it’s far better to get your roof replaced on a regular 20- to 25-year schedule than to wait until you experience leaks, we’re here to help you determine if it’s time for an overhaul.

Roof Age

The first indicator of whether it’s time to replace your roof is age. How old is your roof? As we mentioned above, the average roof lasts about 20 to 25 years. Keep in mind that this could vary significantly based on the materials your roof is made of and the types of weather it has been exposed to over the years. If it’s been 25 years or even longer, it’s pretty much a given that it’s time to start planning for a replacement.

Missing and Damaged Shingles

Did a particularly violent storm recently leave your yard littered with shingles? If not a full replacement, it’s definitely time to call a professional out for a consultation. Even if you can’t recall any storms in your recent past, you may want to grab a ladder and carefully take a look for missing shingles anyway. As roofs age, shingles tend to loosen in strips, and this could be an indicator it’s time for a new one. Look for shingles that curl, buckle, crack or appear to be losing granules.

Chimney Flashing Materials

Flashing refers to material that’s used over joints in a roof to prevent water seeping in. As you can imagine, damaged flashing can be one of the worst-case scenarios for your home’s overall condition. Once upon a time, it was common for roof flashing to be made from roof cement or roof tar. Now, the preferred flashing material is aluminum or galvanized steel. If your spot outdated flashing materials on your roof, it’s a safe bet that a replacement is right around the corner. To determine any damage, we recommend having a professional out to assess your roof’s flashing.

Moss and Algae Growth

Algae is more of an eyesore than a real threat to a roof, but it can cause damage to shingles over time. The most common type of algae is an airborne strain that leaves behind black streaks.
Moss often grows in areas with limited sunlight, and it’s also a cosmetic issue with potential to damage shingle granules. You’ll want to hire a professional for removal and the diagnosis of any accompanying problems.

Your Neighbors Are Replacing Their Roofs

This isn’t about keeping up with the Joneses, we promise. It only makes sense that homes that are a similar age and that have experienced the same weather patterns over the years would need replacing in the same timeframe. If your neighbors are shelling out, take note.

Call National Property Inspections for an Assessment of Your Roof

We have the experience and expertise to perform an inspection of your home’s overall condition, including the roof, foundation and more. Give us a call today to book your appointment.

September 2018: End of Summer

Ask The Inspector

Ask The Inspector

Building Permits: Why You Need One and How to Get It

As a home improvement guru, you might have the idea that building permits are a nuisance. While it’s true that building permits can be a pain, they actually serve a very important role that makes the process worthwhile. We’ll explain why building permits are a thing, why you need one and how to get one. Learn more

5 Signs You Might Have a Foundation Problem

Foundation issues can easily be one of the most expensive things you’ll deal with as a homeowner. Since literally everything rests on your foundation, you can see subtle signs that might spell trouble all over your house—you just have to know where to look. Learn more

How Long Your Appliances Will Last

Whether you’re getting ready to move into your new home with its own set of aging appliances, or you’re just taking stock of the ones you already own, it’s helpful to know just how much life is left in them. Here’s a breakdown of how long each appliance should last and how you can lengthen their lifespans. Learn more

Expert Advice

Ask The Inspector


How to Remove Paint from Wood

Removing paint from wood can be painstaking, but it’s definitely worth it for the results. We’ll show you the best tools and techniques to make the process as easy as possible. Learn more

Your Guide to the Humble Hammer

Few tools are more essential and multifunctional than a hammer. Hammers aren’t as simple as they look, though—there’s a variation for every job you can think of, and using the wrong one can be a waste of time and material, or even dangerous. Here’s a handy guide to some of the most common types of hammers and what they’re used for. Learn more

How to Tell If You Have Hard Water

Hard water. Soft water. If you’re not sure what the difference is, or what that difference means for your home, you’ve come to the right place. We’ll explain everything you need to know about hard water and how to tell if it’s an issue in your home. Learn more

Snapshots From The Field

What’s wrong with this picture?

Pictured here is the entrance to the attic in a brand new construction. But there appears to be something blocking the doorway—a roof truss!

When building or repairing a home, blocking any entry point should be avoided at all costs, but trusses present an especially big challenge. Since attic trusses support your home’s structure and help bear the weight of the roof, they play an endlessly important role in your home’s overall condition. Some trusses are more crucial than others, but it’s difficult to tell exactly what the “workload” of each truss is. To keep your home and family safe, you should never cut or attempt to remove a truss without a consultation from a professional engineer.

As for whether the truss blocking access to the attic in this new home will present a problem, it’s still up in the air. At worst, if any mechanical systems have been installed in the attic, it could be impossible to remove them for maintenance or replacement down the road without cutting the truss. At best, the partially obstructed access could prove an annoyance for the homeowners when it comes to placing items in the space for storage or other maintenance matters.

Maintenance Matters

Ask The Inspector

Do I need a new roof?

If you’ve asked yourself the question, “Do I need a new roof?” you might be wondering exactly how you can tell. Since it’s far better to get your roof replaced on a regular 20- to 25-year schedule than to wait until you experience leaks, we’re here to help you determine if it’s time for an overhaul. Learn more

8 Cleaning Tasks You Might Be Overlooking

Keeping a neat and tidy house is no easy task, and you’ll inevitably overlook a few much-needed cleaning duties from time to time. Here are eight oft forgotten jobs that are worth the extra effort for a healthier, happier home. Learn more


Monthly Trivia Question

Question: Which type of furnace typically lasts longer by up to three years, gas or electric?
Be the first to answer correctly and win a $10 Starbucks’s gift card. Submit your answer to find out if you’ve won.