Have you ever taken a good look at a modern roof? You’ll probably notice pipes and metal hoods sticking out of it. Most homes have at least a few penetrations for different venting systems. Having the right vents in the proper places prevents property damage and health risks.
Roof vs. Plumbing Vents
Many of the vents on a roof are connected to the attic ventilation system. These allow your home to breathe. They create an escape route for warm, moist air and invite fresh air in.
Ventilating your roof correctly provides the following benefits:
- Regulates the temperature throughout the home
- Prevents condensation in the attic
- Reduces the risk of mold and mildew growth
- Prevents ice dams from forming
- Helps your HVAC operate efficiently
- Reduces electric bills
- Extends the life of your roof
Plumbing vents also peek through your shingles on the roof. These regulate the air in your plumbing network, creating a neutral pressure system. This allows water to flow away from the home when you run water down a drain or flush the toilet. It also prevents sewer gasses from rising up and circulating through your house.
Types of Roof Vents
There are two types of attic ventilation systems. A passive system relies on natural air currents to introduce fresh air and eliminate stale air. Passive systems don’t usually have moving parts. They depend on wind velocity and convection to bring airflow into the attic. These types of vents don’t use any electricity, making them environmentally friendly.
An active system mechanically pushes air through your space. These typically rely on fans to sustain the airflow. Some active roof vents use electricity. However, others are powered by the sun or wind. Because these have moving parts, they require more maintenance than passive systems and are subject to failure. However, they are preferable when venting complex spaces.
Static Vents
Static vents look like small boxes on your roof. They have a low profile and come in a variety of colors to blend in with your roof. The boxes serve as hoods to cover the openings in your roof that lead to the attic. Because rodents and other critters can make their way into these holes, you should cover them with a durable mesh, such as hardware fabric.
When the air in your attic gets hot, it expands and rises. This natural occurrence puts it in the perfect position to exit through the vent.
You need several vents to make this type of system work properly. The wind that moves through and around your home must have a way of entering. Therefore, static vent hoods are often paired with soffit or continuous ridge vents. These intake locations are relatively low compared with the locations of the exhaust vents. They take advantage of the physics of natural airflow to ventilate your attic.
Soffit Vents
If you stand beneath the eaves of your home and look up, you’ll notice that there is usually a mesh material that connects the wall of the house with the edge of the roof. This is a soffit vent. It covers the rafters and prevents pests from entering your home. A soffit vent also serves as an intake for fresh air.
All homes don’t require soffit vents. Some homes have solid soffits, with vents added every few feet. If you have other types of vents throughout your attic, you won’t need soffit vents. If you do have them, though, make sure that they’re not covered by attic insulation. Impeding the air flow will impair the ventilation in your home.
Ridge Vents
Ridge vents are installed along your roof’s peak. These can be passive or active. A passive ridge vent consists of an opening and a ridge cap, which prevents water from entering the vent. An active ridge vent contains baffles, which are ventilation channels that maximize the benefits of the vents.
Baffles prevent snow, debris, animals and insects from entering the vent. They also encourage interior air to escape from both sides of the vent in any wind condition. Ridge vents without baffles may only allow air to flow out one side.
It’s important to combine ridge vents with plenty of intake areas, such as soffit vents. If there aren’t enough additional vents, the ridge vent will serve as an intake and exhaust area and won’t ventilate your attic sufficiently.
Gable End Vents
Gable end vents look like small louvered shutters. They come in a broad range of styles to correspond with your home’s architecture. These types of vents are installed in the exterior wall of your home, just below the gables. Using more than one vent provides passive ventilation in a similar way as opening windows on opposite sides of a room would generate airflow.
Ridge and gable end vents are not used together often. When they are, the gable end vents serve as intake areas, and the ridge vents let the air escape. This might keep your roof cool, but it creates a layer of stagnant air near the attic floor and inadequate moisture control.
Turbine Vents
Turbine vents are small exhaust fans that are placed on your roof. They may begin to spin and encourage air release via convection. However, some turbine vents are powered by electricity and operate regardless of the temperature and wind intensity. Active turbine vents are ideal in areas with little or no breeze.
When your roof or attic can’t accommodate a ridge vent, a turbine vent is an excellent alternative. It has a small footprint and low installation cost. However, it does require more maintenance than other types of vents. Although it’s designed to resist trapping debris, it should be inspected regularly. Lubricating it allows it to move freely and prevents corrosion.
Power Vents
Power vents are connected to your home’s source of electricity and serve as fans to suck hot air from your attic. When you connect them to your thermostat, power vents turn on and off automatically as needed. Although power vents move air forcefully and effectively, they’re not ideal for air-conditioned homes. They tend to remove conditioned air from the living area, making your HVAC work overtime.
Is Your Attic Properly Vented?
Building codes require specific types and numbers of vents for different roof sizes. Therefore, a professional roofer can help you determine whether your attic ventilation is adequate. Although venting represents a small percentage of your roof’s surface, it offers enormous advantages. The right vents keep the roof cool, preserve its shingles and extend its longevity.