11 Jun. 20

Battling Heat & Humidity: Roof Ventilation

Humidity and heat are as hard on your roof as cold winter weather.  Over its average life, a residential roof is subjected to extreme swings in temperatures, humidity, and weather.  Over time it can take its toll on the top of the roof and below the shingles.  It can have an effect on your utility bills, respiratory health, rodents, and especially destructive insects like termites.

In Southern states, the exposure to humid days is longer and higher than in other regions of the country.  Moisture is not kind to roofing materials over time.   For those living in the South with longer stretches of warm air and humidity, it can cause premature damage to your roof.  

In hot weather, the rafters, joists and plywood decking can expand.  The expansion can also cause the sealant around flashing to crack, stretch, and form gaps allowing moisture to further penetrate under shingles trapping the intruding water form and preventing the shingle to perform properly.  The shingle’s primary job is to protect the roof deck underneath, but water intrusion and trap humidity sources causing mold, mildew, and wood rot.  

Once the integrity of the roof deck is compromised it is only a matter of time before water intrudes to the attic and finished ceilings are damaged.  This can cause respiratory issues and increase the symptoms of those who battle preexisting allergies, asthma, and other conditions.  Roofing and attics with moisture, mold, mildew, and wood rot are like a food buffet for termites and carpenter ants.  The destruction they cause can far exceed a roof repair or replacement.  

Shingle technology and development has seen so many improvements over the years.  However, even with newer shingle manufacturing techniques it still cannot overcome these factors beyond its average lifecycle.  Similar to the heat that forces wood rafters and decking to expand,  solar heat can force shingles to contract to the point that roofing nails pop through the shingle compromising its integrity and ability to keep moisture elements away from the wood decking.  The shingles become raised and begin to deteriorate faster than normal.  Unrepaired shingles can continue to pull and wear allowing more humidity to reach the roofing surface.

Proper roof ventilation is one of the best ways to help reduce the damage of humidity and moisture.  Ventilation allows the air to circulate and remove moisture and humidity.  The airflow prevents heat from getting trapped on the attic side of the roof and causing damage.  Your air conditioning unit will appreciate less stress as the hot air is removed from the house and proper ventilation will help cut energy bills.  

Most homes are properly ventilated, but soffit, ridge and gable vents can become clogged/obstructed over time and even experience rodent damage.  Intake and exhaust ventilation are critical to the proper rate of air exchange to extend the life of a roof, mitigate moisture and help with utility expenses.  

A roofing professional can advise whether or not your home is adequately ventilated.  If you are noticing condensation, mold, or mildew on your beams, joists, or roof deck from inside these could be signs of improper ventilation or roof damage.  A professionally trained roofer can assess the condition of the roof, ventilation status, and provide a recommendation in writing.  

Gilstrap Roofing has been covering the roofing needs of the Upstate since 1935.  We are a family-owned, local business.  Proud of our BBB and Angie’s List ratings.  Contact us today for all your roofing questions and needs.

Brian Gilstrap, President  

Gilstrap Roofing

Greenville, SC 29611