It can be easier to effectively ventilate the attic and prevent roof damage if you know the components that go into it and how they all work together.
Initially, ventilation in an attic may seem a little counterintuitive: you insulate your home to lessen temperature changes and save money on utility bills, yet you still need to allow fresh air to circulate through the attic year-round.
However, the science underlying attic ventilation is solid. Attics that are well sealed retain extra heat and moisture, which can cause shingle life to be shortened and other problems. Furthermore, excessive heat is a problem all year round; in the winter, warm attic air can melt snow on the roof during the day, only to freeze over again when temperatures drop overnight. This may result in ice dams, which may damage the roof and cause leaks within the house.
However, ensuring that your home has enough attic ventilation will spare you the stress and inconvenience of needing an emergency roof repair.
Attic Ventilation's Functions
Attic ventilation lets air enter the attic as well as leave it. Roofs face the sun, which allows them to produce a lot of heat in the summer. This increase in heat has a way to escape owing to attic ventilation, which also lets in the fresh air.
Additionally, throughout the winter, attic ventilation reduces moisture buildup. Warmer air can carry moisture better than cooler air, which cannot. Therefore, the humidity in the air will condense into the cool attic air and be deposited on the roof deck’s insulation, rafters, joists, and underside.
Basics of Attic Ventilation
The idea behind attic ventilation is that warm air would naturally rise. In order to ventilate an attic, there are primarily two types of vents:
Intake vents can be found high up on the sides of the house inside a roof or as shingled intake vents that are built on a low part of the roof, under the eaves at the lowest point of the roof. The attic might receive cool air thanks to these vents. At the roof’s highest point are exhaust vents, which let heated air leave the attic.
The most typical method of attic ventilation is called passive ventilation and involves utilizing this natural process. The basic rule of thumb is to install at least 1 square foot of vent for every 300 square feet of attic floor in order to promote this circulation of warm and cool air. Local building codes can differ, so be careful to inquire about your neighborhood’s rules with the local building authority.
Attic Ventilation Naturally
Although it may initially seem strange to add insulation for warmth while also intentionally allowing cold air to enter the attic through vents, this combination is essential for a long-lasting house that uses little energy. Here’s why: Keeping the attic cool in winter lowers the risk of ice damming by allowing a natural flow of external air to ventilate it (snow that melts off a roof from an attic that is too warm and then re-freezes at the gutters, causing an ice dam that can damage the roof). By preventing the entry of heat and humid air from below, adequate insulation and air sealing also help to keep attics chilly during the winter.
Natural air movement in an attic with good ventilation carries the extremely hot air out of the attic throughout the summer, preserving the roof shingles and removing humidity. The insulation will resist the transference of heat into the house.
When installing insulation, the most frequent error made by homeowners is to obstruct the airflow at the eaves. Use rafter vents and soffit vents to regulate airflow; never cover attic soffit vents with insulation.
Attic Ventilation with Fans
By pulling in cooler outside air from attic vents (soffit and gable), attic fans are designed to cool hot attics by forcing hot air outside. Attic fans will draw cool, conditioned air from home and pull it up into the attic if your attic has blocked soffit vents and is not tightly sealed from the rest of the house. Your air conditioner will have to function at an optimal level and use more energy; as a result, raising your summer power bill.
Your air conditioner shouldn’t cool your unfinished attic. Follow the insulation and air sealing recommendations in this manual to avoid this, and make sure the attic is adequately ventilated by using passive vents and natural airflow.
Setting up Rafter Vents
Installing rafter vents will allow you to insulate your attic floor all the way up to the eaves (also called insulation baffles). You will get the maximum performance out of your insulation if you completely cover the attic floor and block air leaks. Rafter vents guarantee that the soffit vents are free of obstructions and that there is a path for outside air to enter the attic through the soffits and exit through the gable or ridge vent. Staple the rafter vents directly to the roof decking to install them. For various rafter spacings, rafter vents are available in 4-foot lengths and 14-1/2 and 22-1/2-inch widths.
At the junction of your attic ceiling and floor, where the rafters meet, you should install rafter vents in your attic ceiling.
Once they are in place, you can blast insulation out to the very edge of the attic floor or lay insulation in the form of batts or blankets. To stop the insulation from being blown into the soffit, blown insulation may need an extra block. This is best accomplished by placing a piece of stiff foam board around the top plate’s outside edge.
Check out Suffolkwx.com if you’re interested in energy-saving methods and avail of their excellent services.