How Much Hotter Is It On A Roof

Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic.

How much hotter is it on a roof.

The hotter an attic is the more expensive it is to cool the upstairs of a home. The roof pitch is important in determining the appropriate installation method and how much roofing material will be needed. How hot your roof really gets in the summer is a variable you have some control over. A dark roof won t necessarily get that hot if you don t live somewhere that gets a lot of heat in the first place.

Plus new coating technologies are being developed all the time. However except for reflective coated shingles some energy star rated shingles for instance or white or bare metal there is only about a 10 15 difference in the amount of energy absorbed between black and say a tan or beige and only a few percent between black and a gray red dark blue green or brown. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot. This can easily create attic temperatures as high as 125 f.

Color of your roof as you ve probably heard from many the color of your roof does affect how much heat is absorbed into your attic. In cold climates roofs can accumulate moisture through condensation and it is possible that cool roofs might be more susceptible to. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. Some roof coatings include special chemicals that prevent mold or algae growth for a few years.

Traditional roofs employing asphalt shingles vented attics and insulation on the floor of the attic can get extremely hot with surface roofing temperatures reaching up to 190 f during the summer. Hot air exhaust vents located at the peak of the roof allow hot air to escape. In warm moist locations cool roof surfaces can be more susceptible to algae or mold growth than hot roofs. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

It is often compared to slope but is not exactly the same. A roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. A federal study has shown that the plywood under dark roofs in direct sunlight is consistently 10 to 15 f hotter than the plywood boards under light colored roofs.