Inspections of Texas

The Real Secret to Long Roof Life

The cost of a new roof in Texas ranges between $4,000 and $45,000.  When buying a new roof there are different materials, colors and styles to consider.  Some companies offer 25, 35, and now even 50 year shingles.  As you might expect, the longer life shingles are a higher price.  In the Houston Metropolitan Area, a 25 year shingle has an expected life of 12 to 15 years and a 35 year shingle has an expected life of 20 to 22 years.  Because the 50 year shingle is a fairly new product, there is no information to determine the expected life in the Houston area yet.

However, one factor greatly determines the life expectancy of roof shingles.  That factor is VENTILATION.  The roof structure is supposed to have a balanced ventilation of upper vents and lower vents.  With proper ventilation, the roof stays cooler and shingles have a longer life.

According to the International Residential Code the minimum amount of attic ventilation is 1/150, which means for every 150 square feet of attic floor space you should have 1 square foot of Net Free Area.  This is calculated by the length multiplied by the width of the attic floor. 

When a roof is ventilated correctly, the temperature in the attic should be within 10 to 15 degrees Fahrenheit of the outside temperature.  Houston is known for their “hot attics,” so most people don’t realize there is a true problem.  Extra hot attics are cooking the shingles, breaking down the membrane that holds them together, and sometimes causing the shingles to warp. 

In the last week of July I recorded 156 degrees Fahrenheit in an attic.  What can that kind of heat do?  That is within the tolerance to keep food warm enough to not grow harmful bacteria under a warmer (135 degrees F).  Salmonella dies at 146 degrees F.  156 degrees F is hot enough to melt some metals known as fusible alloys.  Phosphorus melts at 111 degrees F and Potassium melts at 146 degrees F.  It is also hot enough to cause permanent brain damage with heat stroke if a person is in the attic more than 5 minutes.

There is always a danger of heat exhaustion in the Texas summers while outside.  Being in an attic with no air movement is even more dangerous.  High heat in the attic also affects the efficiency of the air conditioning system.  It only makes sense that the air conditioner has to work much harder in an area that is hotter than normal.  This means higher electrical bills and more frequent maintenance. 

Part of our inspection at Inspections of Texas is to consider whether or not the house is ventilated correctly.  If it is not balanced, or it is obvious there is not enough ventilation, we let our clients know.  Our comment has a video attached that was designed by a roofer.  In about 3 minutes our clients know more than about 95 percent of people thanks to this video:

Protect your investment.

Make certain you get every year of life out of your Roof and your Air Conditioning System. 

Keep your Roof Ventilated.

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