Why Is Winter Attic Ventilation Important? – Family Roofing

Posted on by David Reid

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At Family Roofing, we take great pride in our experience, expertise, quality and customer service. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. Our reputation is based on service, safety and quality, regardless of how large or small the job.

 

Why Is Winter Attic Ventilation Important?

Proper attic ventilation protects against many troublesome home problems, making your house more comfortable indoors. It protects your roof against damaging moisture problems, including:

  • Moisture variations that can warp roof decking

  • Mold growth

  • Frost

  • Wood rot

  • Popped shingles

  • Ice dams

In the winter, heat in your home rises – to the attic.  With it comes moisture.  When attics are not well ventilated, moisture collects in this area of the home.  This moisture can seep into the structure of your home, affecting roofing materials as well as framing and contents of your attic.

Adequate attic ventilation allows cool, dry air from outside to come into the attic, while warm, moist air inside the attic can escape.  Good attic ventilation helps keep temperatures even, preventing hot and cold spots that cause damaging ice dams where water can back up and freeze beneath your shingles.

Proper attic ventilation in winter prevents mold and mildew growth, safeguarding your family against these harmful contaminants.  Eliminating moisture problems through attic ventilation works to improve indoor air quality.  It also prevents the warm, damp, and dark environment that pests love, keeping rodents and insects from nesting in your attic.

ROOF VENTS NOT JUST FOR SUMMER

When people think of roof vents, they often think about cooling a hot summer attic.  But roof vents are as important during winter months.

YOUR ATTIC SHOULD BE COOL IN WINTER

Your attic in winter should be only a few degrees warmer than external air.  And the only way to keep your attic cool in winter is proper air circulation.

INADEQUATE ATTIC VENTILATION

During winter, windows and door are left closed for months on end and air in living spaces is heated most of the time.  Moisture vapors from cooking, cleaning, and bathing are carried by warm air into your attic space.  Overtime, without proper attic ventilation, that moisture can buildup on attic surfaces leading to mold, mildew, and wood rot.

INTAKE AND EXHAUST VENTS

Attic ventilation is divided into two categories – intake vents and exhaust vents.  Intake vents draw outside air into the attic while exhaust vents allow hot, moist, or stagnant air to flow out of the attic.

INTAKE VENTS

SOFFIT/EAVE VENTS

Intake vents play an important role in keeping your attic cool in winter (and summer). Intake vents are typically installed at the soffit or eave.  These vents draw external air into the attic.  Homeowners should verify that all soffit and eave vents are properly installed.  Too often we find external vents are blocked (holes are not cut thru to the attic space).

Don’t assume you have ventilation just because you see ventilation screens or vents at the eave. Always check!  Additionally, vents can be blocked by insulation within the attic because baffles are not installed or are improperly sized.

EXHAUST VENTS

STATIC ROOF VENTS

Static roof vents allow air to escape from the attic.  Often multiple static roof vents are needed to adequately ventilate the attic.  Roof vents should be evenly spaced across the roof and installed just below the peak of the roof where heated air will rise.  Static vents do not require electricity to work and thus are less expensive to operate.  They are available in a variety of colors allowing you to choose what will look best with your roof.

RIDGE VENTS

Ridge vents also called Ridge Cap Vents are installed at the ridge of the roof.   Ridge vents are often covered by the roofing material used on the rest of the roof making them blend to the look of your home.  Designed to avoid the need for roof vents, performance has been mixed due to subzero temps and snow levels that can interfere with ridge vent air flow.

When using a ridge vent it is necessary to have an equal or larger amount of intake ventilation from the soffit area of the roof. This allows for air to enter at the lower vents and travel up to the top of the roof as it heats and exits out of the ridge vent. An inadequate amount of soffit ventilation will act to retard the effectiveness of your ridge vent.

POWERED ROOF VENTS (ATTIC FANS)

A powered roof vent can dramatically improve the flow of air through your attic.  Attic fans are covered by a dome to keep the elements from entering the opening in your roof.  The fan is connected to a thermostat or a humidistat/thermostat combo that dictates when the fan should activate based on current temperature or moisture levels in the attic.  One attic fan can produce the same results as multiple static roof vents.

BATH FAN & DRYER EXHAUST VENTS

Bathroom exhaust fans and dryer exhaust tubes should always be exhausted externally via a dampered roof cap.  Never exhaust your bathroom fan or dryer into your attic.  The warm moist air exhausted from both of these sources can lead to mold and damage to your roof and home structure.  If you purchased this home after your bathroom fans or dryer exhaust were installed, you may want to make sure these are venting properly.