Ideally, an attic ventilation system provides intake vents near the eaves and exhaust vents at or close to the roof’s peak. This ventilation balances air flow to keep the attic cool and dry and prevent costly roofing or structural damage.
Inadequate attic ventilation allows warm, humid air to leak into living spaces. This moisture supports rot on ceiling framing, wall sheathing, and other structures and can also ruin interior paint. Call Roofers Daytona Beach today to schedule your appointment!
Heat Buildup
We all know that heat rises, but when it becomes trapped in a poorly ventilated attic space, it can cause temperatures to rise throughout the house. This can lead to stifling and stuffy rooms, and it may also damage the roof and other roofing materials.
The solution to this is a venting system that allows cool air to enter the attic and hot air to exit, creating a constant flow of air in and out of the attic. This ventilation is essential for cooling a home in the summer, protecting against the buildup of mold and mildew, and helping to reduce energy consumption.
With proper attic venting, moisture is less of a problem as well. Everyday activities in a dwelling create humidity which rises through the ceilings and into the attic. This moisture combines with the cooler attic air and meets cold surfaces in the attic, releasing condensation that can wreak havoc on shingles, wood rafters, and other structural components of the attic space, as well as lowering the quality and insulative properties of attic insulation.
Proper attic ventilation prevents these problems and enables the moisture to be carried away from the structure by the wind, rather than lingering in the attic to cause premature shingle failure and damage other building materials. This is why most building codes require attic space ventilation to be adequate, as per the International Residential Code (IRC).
There are several ways to provide attic venting, including passive ventilation that relies on the natural pressure differences between the lower part of the attic and the upper part to allow air to move through the attic and out through exhaust vents located at ridge lines or high in the sides of gable roofs. Another option is active ventilation, which uses mechanical means to assist the flow of air through the attic. This includes a system of intake vents located at the soffit and exhaust vents at the ridge line. The addition of a fan can further increase the rate at which air is turned over to help reduce moisture and heat accumulation.
Moisture Buildup
Many home and commercial structures have attics that are not adequately ventilated. While it is important to insulate the attic to reduce cooling bills and extend shingle life, it is equally important to keep attic air flowing throughout the year. Inadequate ventilation can cause the attic to act like a solar oven during summer, cooking the insulation and causing the roof surface to deteriorate. The result can be a host of problems, including sagging ceilings and the need for expensive repairs.
The key to proper attic ventilation is a balance of intake and exhaust vents. In a balanced system, cool outside air enters the attic through soffit or eave vents, rises in the attic space, and exits through vents located near the top of the attic. This type of attic ventilation is called a natural or passive system. It relies on two major forces — the stack effect and wind force — to create a consistent volume of air movement through the attic space.
If the attic is not properly ventilated, heat and moisture build-up in the attic can rot and stain ceilings and insulation and cause air-conditioning systems to work overtime to cool a building’s living spaces. The excessive heating of the attic and living spaces also increases energy costs.
Poor attic and roof ventilation can also contribute to ice dams in winter. Ice dams form along the edges of the roof when snow accumulates and re-freezes. Proper attic and roof ventilation reduces the amount of melting snow that collects and vents to the conditioned space and can help prevent ice dams by reducing the temperature of the roof surface in winter.
Adding roof and soffit vents to your home is easy, inexpensive, and can be done in just a few hours. To see if your attic is properly ventilated, look in the soffit and eaves of your home and make sure you can see at least one intake vent, such as a gable or louvered soffit vent. If you cannot see any vents, or your home only has ridge vents, you should consider adding more.
Ice Dams
Ice dams are more than just an eyesore, they can cause roof and wall damage that requires expensive repairs. They can cause water to leak into ceilings and walls, causing structural framing members to rot and mildew to grow. They can also cause metal roofing to rust and wood siding to deteriorate. Fortunately, most of these problems can be avoided by proper insulation and air sealing and by adequate attic ventilation.
Many people mistakenly believe that ice dams are caused by roofing, ventilation, or gutter problems, but the truth is far more complicated. Ice dams form when heat from the living spaces of a home gets into the attic and melts the underside of snow on the roof. The melted snow drips down the roof surface until it reaches a cold spot, usually near the eaves or gutter, where it re-freezes into a frozen dam. The resulting ice dam prevents the drainage of melted snow and allows water to back up behind it. This water can cause shingle damage, sagging gutters, and water stains on ceilings and walls below the roof.
Inadequate attic ventilation is a common cause of ice dams in homes. When ventilation is inadequate, warm air from the conditioned living areas enters the attic space and warms the underside of snow on the roof. This causes the snow to melt, run down the roof surface, and re-freeze at the cold eaves or gutters of the building. This cycle is repeated day after day until the ice dam becomes thick enough to block the flow of water.
Proper attic ventilation will not only lower attic temperatures and minimize air conditioning energy costs, but it will also help prevent ice dams and the resulting water damage. The best way to ensure that a home has adequate attic ventilation is to air seal and insulate before winter arrives.
A properly ventilated attic will have both intake vents and exhaust vents. The intake vents are located in the soffit and the exhaust vents are typically found in the ridge at the top of the roof. The intake vents should be placed close to the eaves, but not so close that they disturb the air sealing between the soffit and the wall and create an air leak. The exhaust vents should be close to the ridge so that the natural tendency of heated air to rise will draw out the hot air in the attic.
Mold Growth
Mold needs a moist environment to grow, and attics are often moisture-rich environments due to the nature of their design. Poor ventilation, especially when combined with roof leaks, allows warm, moist air from living spaces below to infiltrate the attic where it can condense and create elevated moisture conditions favorable for mold growth.
Many homeowners don’t have any idea that mold is growing in their attic spaces. If you have access to your attic space and suspect that you have a problem, the first step is to walk through it to check for discolored insulation which is an indication of leaks or areas where air is infiltrating the attic. You’ll also want to look for wood damage, such as rotted or sagging joists or rafters, water stains on the attic decking or drywall, and any visible mold growth.
Another common cause of attic mold is that dryer vents, plumbing vents, or kitchen and bathroom fans are vented into the attic instead of out through the soffit or other exterior openings. These vents should never be closed, even during winter, to allow cool attic air to flow through and help keep the attic cooler.
If you do have a mold problem in your attic, it’s important to remove any items that are there from the affected area. Any materials that are carried from the attic into a living area above are likely to spread the mold spores to other parts of the house, which is why you should never store any materials in your attic space, especially anything soft or porous such as rugs or old cardboard boxes.
If you have a serious problem with attic mold, it’s always best to have a professional examine it. They can advise you on what long-term solutions are required to address the problem. An experienced attic contractor can help you install the proper venting system to improve your attic’s ventilation, reducing moisture levels and eliminating mold infiltration. Using products such as aluminum soffit, which has built-in vents, can be an excellent choice to promote attic ventilation and avoid expensive attic mold repair down the line.