These days, the topic of energy efficiency is a hot one. Not only does being more energy efficient help the environment as a whole, but it also can help your pocket book each month. Energy costs – whether it be gas, electricity, or other forms – are at all-time highs. By increasing your energy efficiency through driving a car with better MPG or making your home more efficient can be a great help when trying to pay the bills.
One of the biggest influences on the energy efficiency of a home is the type of roof that it has installed over it. In Arizona, obviously the number one concern is keeping the constant heat out of your home. When the hot desert air gets into your home, it can be very expensive to run the air conditioner long enough to return the house to a livable temperature. When building a home or business building, or having one re-roofed, picking the right material for your roofing project can make a big difference down the line.
What makes a roof energy efficient?
Basically, for a roof to be energy efficient, it needs to do a good job of blocking the heat out instead of absorbing it. When a roof absorbs heat, that warmth is transferred into the air inside the building radiantly, and pretty soon the entire interior has gotten much warmer. A roof that bounces the sunlight off and reflects the heat back out into the atmosphere will do a much better job of protecting the home or business from hot air.
Roofs that have reflectivity such as white TPO, PVC and Elastomeric Coatings are the best. Cool roofing is probably the most popular and effective energy efficient roof for commercial properties in Arizona. With so many years in the business, Jim Brown and Son are the EXPERTS in cool roofing in AZ.
Residential shingle manufacturers also have cool roofs but are very expensive and not yet worth the cost. They rate the energy efficiency of the roofs by what’s called SRI values. You will have a hard time finding SRI values on shingles unless they are a cool series such as GAF’s Cool Series or Owens Corning’s Duration Premium Cool. A common misconception is the lighter the color shingle the cooler the house will be. This is only true if they purchase an all-white shingle such as Owens Corning Shasta White. Any other color will be the same because shingles are an asphalt-based product. The way the cool shingles work are the granules are coated in a chemical that reflects the heat. The down side is that coating wears off in time and you lose your reflectivity – that is where the cost vs. savings comes in to play.
Somewhat surprisingly, another material for this job is a metal roof. You might think that metal would not be a good choice because it gets so hot when it sits out in the sun – but that is exactly why it works so well. The surface of the metal that is exposed to the sun is super-hot because it is reflecting all of that light. Underneath the metal, however, remains relatively cool because the heat has been reflected away. Most commercial buildings have metal roofing substrates, then the roofing company will install insulation (ISO) on top of the metal with a single ply membrane such as Firestone 60mil TPO, or Duro-Last PVC.
Another good choice for energy efficiency is a concrete tile roof. The tiles are very resistant to all kinds of weather, and do a good job of blocking the heat out. While not as reflective as cool roofs, the concrete tiles don’t get very hot themselves, so they don’t radiate the heat into the building like some other materials will. Another bonus to concrete tile roofing is that the tiles are often warrantied for 50 years or more, and the tiles can have extra reflective coating painted onto them for even more sun blocking power.
Asphalt shingles, one of the most common forms of roofing found all throughout the country, is one of the least effective from an energy efficiency standpoint. The asphalt material soaks up the heat, and radiates it to the inside of the home or business. While shingles are generally the least expensive roofing option on the market, it is best to make sure your attic is properly insulated.