6 Advantages and Disadvantages of Cool Roofs

Cool roofs provide protection from solar heat in hot climates or on hot summer days. This innovative roof is designed to reflect sunlight from a building rather than absorb heat and allow it to enter the structure below. In the past, homeowners relied on white ceilings to reflect the sun's rays.

While lighter colors are much better for reflection, new technology and modern designs allow for more richly colored roofing materials with similar reflective properties. This means homeowners can now enjoy the benefits of cool roofs without sacrificing aesthetics.

Some reflective shingles or tiles can provide these cooling properties, as can paint-like thermal coatings and sheet-like coverings. The best type of material for your roof depends on:

The desired degree of reflectivity

Other heat-conducting factors

Total project budget

Below are some tips to help you take advantage of cool roofs.

A Closer Look at the Benefits of Cool Roofing

How cold is a cold roof? According to the Department of Energy, the surface of standard roofs (without any special reflectors or heat-conducting features) can exceed 150 degrees Fahrenheit in summer. The average cold roof surface can be as low as 50 degrees. Lower surface temperatures mean less heat is passing through the roof into the home, which translates into lower air conditioning costs.

Cool roofs can greatly improve comfort levels in non-air-conditioned rooms such as garages or furnished attics—both are known to get uncomfortably hot during the summer. In addition, since the roof itself is not reaching such extreme daily temperatures, it can last longer and require less maintenance during its lifetime.

Benefits beyond the Home

The benefits of these roofs extend outside the house as well. Solar gain can cause something called the "urban heat island effect". If all homes in a city or suburban area are absorbing 150 degrees of temperature, they can cause an increase in the local ambient temperature. Since the cool roof reflects sunlight and warms upstairs, it can reduce the heat island effect.

What Principles Work at Cool Roofing?

A cold roof reduces heat in two different ways. Its most important property is "solar reflectivity", which means that sunlight is reflected rather than converted into heat. This leads to the other important theory, "thermal emittance," which occurs when the roof releases heat from the sun back into the air instead of absorbing it. Therefore, not only does it feature a cool roof that reflects light, but it also pushes heat away from the house.

Options for Cool Roofing

One option for cool ceilings is to add a lighter color to a paint-like coating. Applied with a roller, brush, or paint sprayer, this thermal coating forms a reflective layer on top of the ceiling. It can also provide additional benefits, such as covering existing leaks and cracks and making the roof look new without having to install a new structure. All this is possible only with the help of these cool roof paints. You can learn about High Albedo Paint for a good cool roof paint and use it for the roofs of your homes.

How much can I save?

Savings vary based on things like location and available natural shade. However, studies show that cool roofs can reduce cooling costs by 40 percent compared to a standard "dark" roof. These savings mean that a new roof or coating may pay for itself in six years or less.

Drawbacks to Consider

The ability to absorb solar energy can be a positive trait in some situations. In cold climates, solar gain can sometimes reduce heating costs during the winter. However, in more northern climates where this may be the case, daylight hours are limited during the winter - and the roof may be covered with snow, which would block sunlight anyway.