Will a Metal Roof Make My Home Hotter?

Always wondered if a metal roof would make your home hotter? Well, putting a metal roof on your home will not make your home hotter. How hot your home’s interior will get, depends on two major factors. One being your roof material and the other being your roofs construction.

Roof Materials

The metal roof itself would not make your home any hotter than your existing roof material. The exterior of your metal roof itself will actually cool off much quicker (once the sun goes down) than your existing roof.

When metal roofing is exposed to direct sunlight, it will certainly heat up, but whether or not it heats up more or less than other roofing materials has more to do with the color and type of finish/coating.

It’s fairly common knowledge that pale colours absorb less heat than dark colours. It should also be known that similarly coloured roof products, regardless of what they’re made from, will absorb heat at roughly the same rate (with the exception of specially engineered ‘cool roof’ products).

Cool metal roofs reflect a portion of the suns energy, contributing to a lower building temperature during hot weather. Cool metal roofs have coatings specifically designed to reflect the suns energy. A standard prepainted metal roof will not reflect as much energy as a cool metal roof, but they still offer a rapid cool down rate when compared to non-metal roofing materials.

After sunset, typically it’s the lightweight roofing materials that will lose their heat fastest and rapidly return to ambient temperature. That’s where metal roofing becomes the clear winner in hot climates. Heavier materials like slate, concrete and asphalt, will absorb and hold heat. The longer they stay hot, the more heat they can transfer to the interior of the building.

Roof Construction

The roof material certainly affects the amount of heat absorbed by the roof. A bigger factor in protecting your home from overheating in hot weather is the construction between the roof material and the interior space below. The structure of your roof typically doesn’t change when installing a new metal roof. If you have a poorly constructed roof, it will continue to cause heating and cooling issues inside your home, even after installing a new metal roof. Having adequate roof ventilation and ceiling insulation is critical in keeping your home’s heating and cooling costs inline. For further information see our post on proper roof ventilation.