Roof ventilation is based on the simple fact that warm air rises. In summer, the sun heats air in the attic. … In either season, good venting occurs when cool air can enter the attic near the eaves and exit near the peak. Ideally, half of the vent area should be low and half high.
How does a roof ventilation work?
How Does Roof Ventilation Work? A roof ventilation system works by providing a continual flow of air through the attic space, helping remove overheated air and moisture from the attic and roof system and reduce the impact of changing temperatures and moisture conditions both inside and outside the home.
What happens if a roof is not vented?
They say that poor or non-existent ventilation might cause attic temperatures to rise to 150 degrees or higher in the summer. That can lead to damaged shingles and other roofing materials as well as a buildup of condensation and development of mildew and mold.
What is the purpose of venting a roof?
Roof vents are important because they extend the life of your roof, reduce energy costs, and reduce indoor temperature extremes. They also prevent damage to your shingles and prevent them from cracking.
Should roofs be ventilated?
Installing roof vents moderates the temperature in an attic or roof space. By preventing a roof space from getting too hot or too cold you reduce the build-up of moisture levels. … Our trained team of roofing experts are often asked if roof vents are entirely necessary. The short answer is, yes!
What is the best roof ventilation?
In most cases, we recommend soffit vents for intake and a ridge vent for exhaust. For homes that cannot have a ridge vent, box vents are generally the second best option for exhaust. And for homes that cannot have soffit ventilation, you will find that fascia vents to be your second best bet.
Can a roof have too much ventilation?
The two main dangers associated with too much ventilation involve roof damage and increased utility bills. If you have too much air circulating, your roof will collect moisture causing damages that will weaken spots and then cause leaking.
How do you know if your roof is properly vented?
How to determine whether you need better attic ventilation
- Look at your eaves and roof. …
- Touch your ceiling on a warm, sunny day. …
- Thick ridges of ice on your eaves in winter are a sign of poor attic ventilation. …
- Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing.
What are the vents on my roof?
Exhaust vents are installed at the top of the roof. Their primary job is to provide an unobstructed exit for the heat, hot air, odors and moisture trapped in your attic.
Is Roof venting required by code?
Enclosed attics and enclosed rafters are required by the California Residential Code to have proper ventilation.
How many vents should be on a roof?
How Many Vents Do I Need? The general rule of thumb in these situations is of roughly one vent per every 300 square feet of attic area if the attic has a vapor barrier. If not, there should be one vent for every 150 square feet. You will need to have 1 square foot of vent area for every 150 square feet of attic space.
Do I need roof vents if I have breathable felt?
Further to what Robbo has said, if you use BREATHABLE felt you do not need any other form of ventilation (i.e. soffit vents or over fascia vents). Breathable felt is very popular now as it is clean and light to handle.
How do you ventilate an old roof?
The most popular roof ventilation solution is to have soffit vents providing cool, fresh air into the loft from a low level, and a tile vent or ridge vent at a high level for the warm stale air to exit the building.
How can I vent my roof without soffits?
One great alternative to a soffit ventilation system is to install an intake vent right at the lower edge of the roof. They call this a venting drip edge. The venting drip edge seems to be the easiest and most common way to go.