Question

Is there any benefit of a membrane cool roof versus elastomeric reflective coatings I've seen advertised?

Asked by JD Burrell
Charleston, SC

I have a small commercial facility. I want to install a cool roofing system, but I want to ensure I get the most cost-effective solution.

Answer

Martin Grohman

Answered by Martin Grohman

Biddeford, ME

GAF Materials Corp

November 2, 2010

Roof coatings aren’t a miracle in a bucket -- if the roof underneath is full of holes, rotting or subsiding, you need a new roof.

  • But if it’s an aged but otherwise intact roof that’s dark colored, you might find big benefits -- not just energy savings, but reduced thermal stresses on the building and an extended roof life -- with a coating.
  • If properly completed in accordance with manufacturer’s instructions (priming, treating seams, tightening fasteners, and other key steps), this coating could be eligible for a 10-year warranty.

Re-covering your existing roof with a new reflective TPO roof is also a good option. It may provide an opportunity for you to add an additional layer of insulation, as well.

Generally, your professional green roofing contractor would use an infrared camera to scan for moisture, replacing wet materials and addressing any concerns identified, structural or otherwise. Then an appropriate layer of insulation would be installed on top of your existing roof, and the new membrane adhered to that.

This would be a more comprehensive roof upgrade that can be eligible for a 25-year warranty if properly installed.


For more information:

Read Susan Wisniewski's Q&A "What's the difference between a green roof and a white roof?"

Tagged In: roofing, white roof

Do you have a question about greening your home? GreenHomeGuide invites you to Ask A Pro. Let our network of experienced green building professionals – architects, designers, contractors, electricians, energy experts, landscapers, tile & stone specialists, and more – help you find the right solution.