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

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

*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...

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Answers

Harold Remlinger, AIA, LEED AP, NCARB's picture

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.