How Much Hotter Is It On A Roof

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.

How much hotter is it on a roof. It s definitely something to consider when re roofing and in a new construction project and you might be able to take steps to cool things down on the roof you already have. In warm moist locations cool roof surfaces can be more susceptible to algae or mold growth than hot roofs. However the color of your roof could make a difference to things like energy bills and how much heating the rest of your home needs. 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.

The hotter an attic is the more expensive it is to cool the upstairs of a home. Hot air exhaust vents located at the peak of the roof allow hot air to escape. It is often compared to slope but is not exactly the same. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

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. How hot your roof really gets in the summer is a variable you have some control over. A roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. In cold climates roofs can accumulate moisture through condensation and it is possible that cool roofs might be more susceptible to.

Plus new coating technologies are being developed all the time. The roof pitch is important in determining the appropriate installation method and how much roofing material will be needed. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. 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.

Yes black will be hotter. 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. Some roof coatings include special chemicals that prevent mold or algae growth for a few years.