While most homeowners realize the importance of having a roof that protects against the wrath of mother nature, most do not understand the impact improper attic ventilation has on the lifespan of your roof system. Heat and humidity, if left unmonitored, can devastate your roof deck and thereby reduce years off your roof’s life. During the hot summer months, shingles can reach temperatures of 150 degrees Fahrenheit. This collected heat will radiate through the shingles and into your attic space, creating a hotbox that, if left unattended, begins to reduce the overall strength of your plywood roof deck. This process is called thermal decomposition. Additionally, if the attic space is poorly insulated, the heat spills down through the attic floor and into the living area, causing your AC systems to work overtime trying to cool the living space. Heat, however, isn’t the only enemy lurking in your attic, there is another – one that is much more difficult to detect and can have serious effects on your health….Humidity!
Issues with humidity getting trapped in your attic are difficult to detect with the naked eye during the summer months. However, during the winter, humidity issues in the attic are much easier to spot. As heat escapes your home from cooking, cleaning, showering, and the act of heating your house, the hot air will rise and begin to accumulate in the attic. As this air becomes trapped in the attic it will create an environment that is slightly warmer than the outside temperatures. When this happens, the humidity will be trapped in the attic as well. As a result, the warm air will condense on the underside plywood deck. Meanwhile, exterior temperatures on the outside surface of your roof are colder than the attic air. When the two temperature differences collide on the roof deck, condensation will begin to form. This condensation will often freeze on the underside of the plywood in your attic, and over time will begin to rust the nails that hold your shingles. Additionally, this will begin to rot the plywood and create an environment for the growth of mold or mildew.
How do you solve this problem? Many homeowners simply assume that you can just add an attic fan as a solution. Unfortunately, that’s seldom the answer. Attic ventilation needs to be properly balanced. This means that the attic space not only needs a method for the heat and humidity to escape, but it also needs the proper intake of fresh air. Ideally, this should occur at the lowest point of your attic space, which on most homes is the eaves where your soffit is located. Today’s homes typically have ventilated soffits that allow for the intake of the correct amount of air into the attic space. However, in older homes, this soffit area was often solid, or the insulation in the attic extended out over the soffit, blocking any air from entering the attic. Experts recommend that for every 150 square feet of attic floor space you have, there should be 1 square foot of ventilation. When this balance is achieved, you are utilizing what is known in science as the stack effect, which refers to the natural forces of wind pressure and thermal effect that cause hot air to rise. Ventilation that is performing properly will minimize the temperature differential between the attic and outside air, thereby reducing the effects of heat and humidity build up as well as the damaging effect of ice damming.
Don’t bang your head against the wall trying to determine if your home has the proper amount of ventilation or insulation. Your best bet is to call Elegant Exteriors, LLC. Our factory-certified contractors will repair your roof and address any issues with airflow that might be causing damage to your home. For a free estimate from the local roofing company that Toms River, NJ and its surrounding area trusts, contact Elegant Exteriors, LLC today!