I need to insulate my attic in South Carolina. The house was built in 1984 and remodeled in 2004.

Asked by John Mosher
Hilton Head Island, SC

There are multiple areas where an air handler would have to be removed prior to spraying foam, and some other areas that would be very difficult to properly seal. Should I still consider using foam? What would you recommend?


Matthew McCullough

Answered by Matthew McCullough

Stamford, CT

The Green Insulation Company

February 22, 2011

If you find a good installer, getting behind the air handlers or ductwork should not be a problem. There are tips that can shoot foam up to 5 or 6 feet pretty accurately (long shot tips).

With the amount of time that you would be running your air conditioner in SC you really want to use foam in your roof rafters.

  • It will dramatically decrease the load on the air handlers, which saves you money on your electric bills, and you are not fighting the 120-degree temperatures in the attic along with the humidity and condensation that comes with that.
  • It's that condensation that will lead to mold and mildew in the attic.

In your neck of the woods, I would recommend about 7-8" of open cell spray foam or 4-5" of closed cell if you don't mind the added cost of closed cell.

Hope that helps.


For more information:

Read "What is the safest and most effective insulation for our attic crawl space?" a Q&A answered by Ian MacLeod.

Tagged In: spray foam, attic insulation

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.