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  • Writer's pictureJoe

Does Poor Ventilation Rot The Roof?

Updated: Aug 17, 2023

As a roofing contractor, one of the most common questions I'm asked is, "Does poor ventilation rot the roof?" While many think of shingles or gutters, the real issue often lies in the attic's ventilation.

Improperly installed attic ventilation doesn’t provide a solution for heat and moisture. Without proper ventilation, moisture gets caught in the roof from activities like showering, laundry, and even washing dishes.

What is roofing ventilation?

Roof ventilation is a system of intake and exhaust vents that provide air circulation to maintain a comfortable atmosphere within your home. Hot air gets trapped in your roof without the passages of roof ventilation. It leads to a variety of costly damage within your home.

Poor ventilation can rot your roof and decrease its life

Water can easily damage your home without the proper safeguards in place. One of those safeguards is effective ventilation.

I’m not even talking about heavy rain or snow. Condensation can lead to costly damage as well. The difference in temperature between the attic and outdoors can result in condensation on the exposed areas of the attic roof.

Over time, as this condensation builds it can gradually rot away the wood. Condensation can also lead to the growth of toxic mold and mildew.

As the fungi spread, two things can happen:

  1. It can reduce air quality in your home and impacts the respiratory health of you and your family.

  2. It can also damage furniture and other belongings stored in the attic.

The benefits of proper ventilation

However, proper attic ventilation allows cool, fresh air to enter the attic at the soffit or eave areas of the roof. The ventilation system also exhausts hot, moist air from the attic through exhaust vents. This intake and exhaust of air prevent moisture problems such as mold and mildew growth and wood rot.

Proper ventilation not only protects your family and your home but also provides energy savings. Your attic can quickly heat up during those hot midwest summer months. As a result, your air conditioner is forced to work overtime to keep up. A well-ventilated attic will help your AC maintain a comfortable temperature without drastically increasing your energy bill.

A properly installed ventilation system will maintain a balance of intake and exhaust as the natural forces of air pressure create a push and pull effect.

Problems caused by poor attic ventilation

  1. Short roof life: Excess heat and moisture cause roof decking to dry-rot and shorten the life of shingles and underlayment.

  2. Mold and mildew: A humid environment is an ideal place for mold or mildew to grow. Mold can damage anything inside your attic and lead to respiratory problems for you and your family.

  3. Rust: Moisture encourages rust to form on structural metal like nails and fasteners. Over time, this can rust the heads off of nails and cause venting or plumbing straps to fail.

  4. Sagging or spongy decking: Excess moisture in roof decking eventually dissolves the adhesives which hold them together and cause it to warp.

  5. Ice dams: An ice dam is a ridge of ice that forms along a roof’s edge and prevents snowmelt from draining off the roof. The snow is melted by trapped warm air that rises to the roof deck. Once a dam forms, water backs up behind it and can leak into your home.

  6. A/C wear and tear: Improper attic ventilation increases the stress placed on your home’s air conditioner. It’s forced to work harder to keep the inside air cool, potentially reducing the unit’s life and increasing your utility costs.

Contact JB Roofing to make sure your roof is properly ventilated

Homes with proper roof ventilation systems are more comfortable throughout the year and often suffer less damage from moisture and heat issues. Effective ventilation improves the performance of your roof insulation, prevents mold buildup, and keeps the attic cooler in the summer and warmer in the winter.

However, each roof requires a unique ventilation system based on its size and design. To learn more about the benefits of proper roof ventilation or to schedule a free roof evaluation, contact your midwest residential roofing professionals at JB Roofing.


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