7 Ways Your Roof Can Make Your Home More Energy-Efficient

Adequate Insulation

Attic insulation is the number one factor that affects your roof’s energy-efficiency overall. A poorly insulated roof will put a strain on your air conditioning system in the summer and your heating in the winter. A well-insulated roof, on the other hand, can drastically reduce your heating and cooling usage, not to mention your electricity bill and your home’s carbon emissions. A thick layer of insulation creates a barrier that decreases heat transfer between a steamy (or frigid) attic and the air in the rest of your house. The great part about adding more insulation to your attic is that you can make this energy-saving home improvement at any time!

Even if you do have attic insulation, it may not be enough. EnergyStar.gov suggests an easy way to gauge whether or not you need more insulation in your attic: Look across the span of your attic and take note of the floor joists. Is your insulation barely level with or even below your floor joists? If so, then your attic doesn’t have enough insulation. However, if you can’t see the floor joists because the insulation completely covers them, then you likely have plenty of insulation in your attic. Make sure that the insulation is distributed evenly in the middle of your attic as well as along the eaves.

Solar Reflection

Solar reflectance is the most important characteristic of roofing products for yielding the highest energy-efficiency during the warm summer months. Roofs that reflect solar heat away from your home instead of absorbing it can reduce the surface temperature by up to 30%!

Another option to help reduce solar heat gain is to install a radiant heat barrier, which is a silver, laminated film coating that’s applied underneath the roof deck (sheathing) and around the beams. A radiant heat barrier helps reflect heat away from your attic during hot weather and reflect heat into your home during cold weather.

NOTE: Bear in mind that the energy savings that can be achieved with reflective roofing are highly dependent on the design of your home, the type of insulation in your attic, where your home is located, and your local climate conditions.

Emissivity Value

Emissivity refers to a material’s ability to release absorbed heat, expressed in a value between 0 and 1 (or 0% to 100%). For example, metal has a low emissivity value because it absorbs and retains heat. That’s why a metal object left out in direct sunlight quickly becomes hot to the touch. Highly emissive roofing products help reduce the cooling load of homes in warm, sunny climates by releasing the remaining heat absorbed from the sun. Conversely, low emissivity roofs are ideal for homes located in cooler climates, since they retain heat and reduce the heating load.

ENERGY STAR Rating

ENERGY STAR certified roof products are more effective at reflecting solar heat back into the atmosphere rather than absorbing and transferring the heat into your home. In fact, ENERGY STAR shingles can lower the surface temperature of your roof by up to 50°F! A cooler roof therefore lessens the need for air conditioning and can reduce peak cooling demand by 10-15%.

Proper Ventilation

A poorly ventilated roof traps hot air inside the attic, which can then pass through the insulation and gradually bake the rest of your house like an oven. This forces your cooling system to work harder and leads to a significant rise in monthly energy bills. Excessive heat in your attic can even warp roof decking and shorten the life of your shingles as well.

Good air circulation is vital to roof health. It’s important to install intake vents along the lowest points of the roof to draw in cooler, fresh air and position exhaust vents higher on the roof to allow rising hot air to escape. This enables a natural airflow circulation process to occur that prevents extreme heat from building up in your attic, which keeps your roof cooler and lightens the load on your air conditioning system.

Shingle Color

The color of your roof should vary based on your local climate. Just like dark clothing absorbs heat on a sunny day, dark-colored shingles absorb solar energy and transfer that heat into your house. For this reason, dark shingles are best suited for homes located in cooler climates.

The opposite is true for homes in warmer areas. Light-colored shingles naturally deflect sunlight to reduce heat transfer to the attic and the rest of the house. Since shingles in solar-reflecting colors stay cooler, their asphalt base lasts longer as a result, extending the life of the shingles and your overall roof structure.

Shingle Material

The most popular shingle materials include:

• Asphalt
• Metal
• Wood
• Clay tile
• Slate tile
• Concrete
• Solar shingles
• Composite plastic
• Rubber

Each of the above materials has different energy-efficiency properties. The type of shingle you choose for your roof depends primarily on your local climate and your home improvement budget. Choosing the right material can reduce your home’s energy needs by as much as 30%!

Clay tile roofs and concrete roofs, for example, absorb and retain solar energy to keep your home warm and well-insulated around the clock. They are also resistant to developing air leaks and drafts when installed properly. Although concrete and clay tile roofs are more expensive up-front than cheaper alternatives like asphalt, the energy-savings they generate will pay for themselves in the long-run.

The most cutting-edge roofing technologies are solar roofs that use small solar panels instead of shingles to produce their own energy. Solar roofs use a type of solar technology called photovoltaic (PV) cells that significantly cut your home’s energy consumption. You can even sell excess solar energy back to the grid to make money!

The least energy-efficient roofing materials are aluminum and unpainted metal, since they absorb solar energy and transfer it into your home instead of releasing it back into the atmosphere. Wood shingles are often not the best choice either because they degrade quickly and need to be replaced every 15 years.