Our Home - Reflective Roof Decking
I’m sure most of you, like me, have climbed into your attic on a hot day. Here in Arkansas on a hot August day, temperatures in a normal attic can reach 130 degrees. I know — several years ago, we had our HVAC system replaced in August. The workers were understandably miserable in the stagnant air. Curious, I grabbed a thermometer and set it in the attic. I was astonished to find that the thermometer quickly registered 130 degrees!
The worst part? My heat/air ducts were run in the attic! In the hottest part of the summer, cool air was running through the ducts in my 130 degree attic. Even though the ducts are insulated, enough heat is transferred from the attic to the air ducts to make my HVAC system work harder and longer to keep the house cool. This was definitely something I wanted to address in the construction of our new home.
The solution? Reflective roof decking. A builder friend of mine told me about this product not long after we started designing the home. Normal roof decking is made of OSB (oriented strand board). OSB comes in 4 x 8 ft sheets and is nailed to the rafters prior to installation of shingles. Reflective roof decking, also called radiant barrier sheathing, has a heat-reflecting foil backing laminated to the OSB sheet. The reflective backing reduces heat transfer from the roof.
The result is a cooler attic in the summer by 15-20 degrees.
The brand that I used is SolarBoard, manufactured by Norbord. SolarBoard is EnergyStar certified. Here are the features listed on SolarBoard’s website. I’ve included my thoughts in italics.
- Reduces radiant heat transfer through the roof by 97%.
- Reduces attic temperatures by up to 30ºF (I’ve found mine to be in the 15-20 degree range, still phenomenal results)
- Increases the efficiency of attic duct work. (I used in-floor ducts in my house to completely eliminate heat transfer from the roof to duct work)
- Prolongs life of heating/air conditioning system.
- Increases comfort level significantly.
- Reduces cooling costs. (We’ve definitely found this to be true)
- Helps hold heat in your home during winter. (That’s why the reflective surface faces inside, toward the attic)
- Requires no maintenance. Does not deteriorate over time.
- As solar heat increases, Solar Board’s effectiveness goes up.
The additional cost for us was approximately $1,000. That’s a small price to pay for reducing temperatures in my attic 15-20 degrees in the hottest part of the summer. Installation was the same as normal roof decking, so this was an easy decision to make. Another positive? I don’t mind making trips into the attic, even on the hottest day in August or September.
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