Expert: Ted Barnhill (Principal, Design45 LLC) - 1/22/2008

Question
QUESTION: Hi, I'm building a home in Florida and I'm stuck with deciding best & efficient way to insulate the space between the 1x2 furring. I would like to spray insulating foam in this area since working around the romex and phone cables attached to the wall using rigid foam board would be a nightmare! Any Comments or suggestions???

ANSWER: Luis-

Both open and closed cell foam can be professionally sprayed and field cut to the face of studs or furring.  Open cell foam like Icynene allows drying of any moisture in the wall, but has a lower R-value than closed-cell foam.  Both are more expensive than batts or boards, but are much tighter so are more effective insulators.

This is not normally a do-it-yourself type operation.  If you are trying to get this done on your own, you could use rigid boards, omitting them around your wires, then spray low-expanding foam in those locations.  This is certainly fussy but more economical.  

Good luck, and feel free to post follow-up questions.  -Ted

---------- FOLLOW-UP ----------

QUESTION: Thanks for your reply Ted.
I can't seem to find any contractor that sprays the foam type insulators in my area (Miami) to consider the cost factor. Only one that I found sprays the cellulose type which is basicly shredded paper doused with flame retardant and anti-bug. Does this type offer an effective "R" value? What are the pros and cons of using this stuff??

Answer
Luis-

The Icynene website provides the following dealer local to you:

Art Foam Insulation
6400 N Andrews Avenue
Suite 505
Fort Lauderdale   FL
33309   United States    Engin (John) T. Eryesil
Phone: 954-640-0700
Fax: 954-615-2000
Email: artfoam@aol.com

A search on closed cell manufacturers may provide other options.

Sprayed cellulose is a messy install, but the R-value is pretty close to Icynene (but less than urethane foam, for example).  Cellulose is considered a sustainable material, though care must be taken to assure complete drying, or you may end up with mold issues in your wall.

If overall R-value is your major concern, you might consider using 2x2 furring or a stud wall to achieve better insulation.

Good luck with your project.  -Ted