Question

I'm trying to decide which roof and insulation is best for my 1950s modern, flat roof home in Daytona Beach, FL.

Asked by Kevin
Daytona Beach, FL

*Getting a tear down, new re-roof soon...(storm damage) *no insulation in 2:12, 30sq roof, all cathedral ceilings....No attic space either. **probably have 50-65% tree coverage... *looking for reduced AC/heat bills... *Leaning towards polyiso and Certainteed Flintlastic SA...

Answer

Kevin,

You have asked the right question but at the same time you have answered some of the basic questions in determining a solution.

Choosing a roof

First, your 2:12 pitch roof. Because of your geographical location and known high winds, I would recommend looking into a standing seam metal roof.

  • This approach will allow you to handle some of the worst weather conditions and comply with the Miami-Dade regulations common in most counties in Florida.
  • One roofing type which meets Miami-Dade regulations is the UC-3 standing seam metal roof profile manufactured by Firestone Metal Products.

Insulating the roof

Second, how to insulate. Contact local foam insulation contractors and discuss a hot deck installation process of insulation. This method fills all of the roof cavities (in your case between each rafter) solid with blown-in foam insulation.

There are two types of foam currently available on the market.

  • Closed cell foam – approximately R-7 per inch thickness of insulation.
  • Open cell foam – approximately R-4 per inch thickness of insulation.

Energy costs

Third, reducing the A/C and heating bills. Obviously installing blown-in foam insulation will reduce heat gain as well as heat loss.

However, you can go one step further to reduce the heat gain by choosing a roof color with a high Solar Reflectance Index (SRI).

  • A roof color with a .50 index is considered to be a cool roof and will absorb less solar radiation equaling a low heat gain on the interior of the building.
  • Keep in mind not all paint colors are equal, so check the SRI prior to specifying and choose a color greater than a .50 index number.

 

For more information:

Read "What type of roof should I choose in a hot climate?" a Q&A answered by Mick Dalrymple.

Check our Find a Pro directory to find a green roofing professional near you.

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