Unsafe Attic Temperatures

What should the attic temperature be relative to the outside and house temperatures assuming a new supposedly well insulated house.

Unsafe attic temperatures.

Field monitoring of numerous attics has confirmed that the temperature of the roof sheathing of a unvented roof will rise by a few to no more than 10 f more than a well ventilated attic. They have done much of their testing in las vegas and phoenix where conditions are the worst and 150 degree attic temperatures are common. The white roof lowered the attic temperature by about 20 f. To head off these problems consider these options for bringing your attic s temperature down.

Most attics aren t made to walk in and insulation duct work and low clearances just increase the difficulty. These images came from a presentation danny parker gave pdf on fsec s cool roof research the third graph shows attic temperatures from the middle of the attic for several different types of roofing as well as a sealed attic. I have to go into attics all the time and believe me i don t look forward to it. Alternatively install passive vents such as gable soffit and ridge vents which.

If your attic soars above 100 degrees and reaches the 150 mark its time to consult professionals. See webb site address above for full text. Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures. If this isn t bad enough add to it the fact that an attic can reach temperatures of 120 degrees on a hot summer day.

High temperatures inside your attic shorten the life span of shingles. Excessive heat deteriorates items you store in the attic and can cause moisture problems in your house. In some cases attic temperatures can reach above the 150 degree mark. Install electric ventilators and attic fans which remove hot air from an attic.

It s also been found that roofing design and materials have more effect on attic temperature than ventilation.