Common Problems Caused By Poor Attic Ventilation

Proper attic or roof ventilation is an important part of the roofing system. Adequate roof venting pulls fresh air into the attic and pushes out heat and moisture. This in turn reduces the temperature difference between the air outside and in the attic. When done correctly, proper roof ventilation will reduce the risk of potential problems and extend the life of the roofing system.

However, poor roof ventilation can cause a variety of problems that can cause damage and lead to expensive repairs. If you’ve ever been in an attic, mid-day on a hot summer afternoon, you are well aware of how unpleasant it can get. If not, suffice to say that temperatures inside can climb to over 150 degrees Fahrenheit and feel like a sauna. This causes your air conditioning equipment to work harder in trying to cool your home resulting in more wear and tear and higher energy bills.

In the winter, heat rising from your home is trapped in the attic which causes the snow on the roof to melt. This usually results in damaging ice dams and related water damage to your home. If not corrected, the repeated leaks will eventually damage the plywood underneath the shingles which will require costly replacement.

The most common problems caused by poor roof ventilation are due to two factors, heat and moisture. Every time we run a load of laundry, take a shower or wash dishes it increases the moisture level in the home and, unless properly vented, in the attic. Trapped moisture and heat can lead to the following common problems:

 Mold & Mildew

A humid environment is the perfect place for mold or mildew to form. Mold can ruin stored items in the attic and cause health problems. The attic should not be used for storage.Rust can begin to form on metal components like nails or other critical fasteners. Over time, it can rust the heads off of nails or cause other metal hardware to fail.

Sagging or Spongy Plywood

When excessive moisture begins seep into the roof plywood, it can begin to dissolve the adhesives which hold  it together and cause it to warp, sag between rafters or feel spongy when walked on. At this point, the only remedy is to replace the shingles and the plywood. Not only can excessive heat and moisture ruin roof decking, it can also reduce the life of the underlayment and shingles themselves. Curling shingles or premature loss of granules can be signs of improper attic ventilation.

Air Conditioner Replacement & Expenses

As heat builds in the attic, air conditioners must work extra hard to keep the air inside the home cool. This undue stress on the unit can reduce its life and increase energy costs.

Frost

Excess moisture in the attic is absorbed by the plywood and other framing members. When the night time temperatures drop below freezing, the moisture in the wood turns to frost as seen in the picture below.  As the attic warms with the higher daytime temperatures, frost formed inside the attic can melt and drip onto the insulation and ceiling below. This repetitive freezing and thawing cycle will eventually cause the plywood to delaminate and buckle which will require replacement.

Ice Dams

Ice dams can form at the edge of a roof where melted snow meets the cold soffit area. As the snow continues to freeze, melt and refreeze it creates a barrier or dam preventing water from running off the roof. Once dammed, water and ice can creep back up under the shingles and underlayment resulting in leaks. Proper ventilation, the elimination of attic heat leaks and added insulation can help mitigate this melting and freezing process and eliminate ice dams.

Free Consultation

If you have the telltale sign of ice dams, give us a call. We’ll inspect your attic, roof and ventilation system and determine what needs to be done to make your home safer and healthier.  It helps with energy efficiency, air quality and comfort of the interior, shingle longevity and the structural stability of your roof.  A little preventative maintenance can only benefit you and your home in the long term.  Don’t wait until you see ice dams on your roof and water stains on your ceilings.  Waiting can cost you thousands of dollars in damage.

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