Vents For Your Roof

In order for your roofing system to perform at its prime, you’re going to need to some vents up there. If you are having a new roof installed, your roofing contractor should be able to discuss ventilation options with you. There are several different ventilation strategies and vent types available, however they all essentially serve the same function: ensuring a good balance of intake and exhaust.

This article is intended to get you ready for a conversation with your preferred roofing contractor about vents for your roofing system, and to help you understand why having a vented attic and roof system is important for your home.

Attic and Roof Vents

First of all, there are several different styles or types of vents that you should be aware of:

  • Attic Fans
  • Roof Vents
  • Gable Vents
  • Louvers

Each of these types of vent either serve as an intake, exhaust, or both.

Why Is Intake and Exhaust Important?

There are two major reasons why installation of intake and exhaust vents are super important for you to have installed in the attic.

  1. The biggest reason is to remove moisture from your attic. Excess moisture allowed to accumulate anywhere within your home can cause some major problems.
  2. The second reason is to allow higher pressure warm air to escape, so that it doesn’t invade conditioned spaces within your home.

In order to have your attic space vented properly you will need to have a balance between intake and exhaust.

The International Building Code requires a minimum ventilation ratio of 1:150. This means that you should have 1 square foot of vent area for every 150 square feet of attic area.

For example. If you have an attic that is 1000 square feet, you will need 480 square inches or intake and exhaust to have a proper balance.

Why Care So Much About The Attic?

Taking care of your attic goes a long way towards taking care of your roof. Thats because much of the roof deck is directly exposed to the attic. Without correct ventilation in the attic you can be opening yourself up to big problems, such as mold, mildew, and potential damage to the integrity of your roof.

Intake Vents

Intake vents serve the purpose of bringing in fresh air from the outside in order to replace air that is expelled from the exhaust vents. Usually intake vents are found under the roof’s eves. There are two types of intake vents that homeowners should be generally aware of:

Roof-Mounted Intake

These vents generally are mounted directly on top of the roof. They are used when a soffit vent is not possible.

Soffit Vents

These are the most widely used type of intake vent. They are found under the eves of the roof, between the joists of your home.

Exhaust Types

Static Roof Vents AKA Louvers

These types of vents are placed flat on the roof near the ridge. They are most often called dormer vents here in the west half of the country, but depending on the area where you live they me be referred to by a variety of names such as:

  • Off-ridge Vents
  • Turtle Vents
  • Slant-backs
  • Box Vents
  • Half-rounds

Ridge Vents

This type of vent can be found along the very top of the roof ridge, right where two sloping portions of the roof come to a peak Their strategic position right at the tippy top of the roof allowed the them to catch the wind traveling over the top of the roof helping them to effective at dispelling heat and moisture from inside the attic.


The spinning blades of a turbine help to create negative pressure inside the attic, sucking out stale air and moisture.

Attic Fans

An attic fan is typically placed on an inside wall of the attic. They can move a lot of hot or moist air from inside the attic to the outside. Homeowners can keep use these fans to help regulate their heating and cooling, as these they can be turned on or off according to necessity.

How It All Works

When you have the proper balance of exhaust and intake vents and everything is working perfectly, you can expect that first air will drawn out from the attic and expelled by the exhaust vents which creates a vacuum, or negative pressure. Next, fresh air from outside rushes in to take its place, coming in through the intake vents.

Now let’s see what can happen if the system is unbalanced. If you have insufficient intake vents or they are otherwise blocked or plugged, the system may begin pulling conditioned air from the inside of your home to balance the pressure gradient. Conversely, if your exhaust is insufficient, the warmer, higher pressure air from the attic can infiltrate inside your home.

Either of these scenarios can lead to energy insufficiency and impact your monthly energy bill, so it’s important to ensure that your intake and exhaust vents are functioning properly. If you have trouble maintaining a comfortable living temperature in your home, you may have a problem with the venting system in your attic.

The Long and Short of It

Hopefully we’ve been able to illustrate the importance of venting your attic. Making sure that you have good balance or intake and exhaust vents can help you save on your monthly energy bill, and expand the lifespan of your roof. If you think you need help with venting your attic properly, find a qualified roofing contractor in your area.