I dont know how many builders offer options regarding framing but I'd like to touch on it a little bit and hopefully get some more input. Framing can usually be described as 2x4 or 2x6 at 16" or 24" on center. This simply describes the depth of the stud, 3 1/2 inches for 2x4 and 5 1/2 inches for 2x6, and the spacing of the studs. In Lake County I see a mix of 2x4 and 2x6 but I rarely see 24" oc. That isnt a scientific position just an observation.



For our discussion this affects how much insulation is installed in the exterior walls. Obviously a 2x6 wall is deeper than a 2x4 which allows the insulation, fiberglass or blown cellulose, r-value to be about 19 instead of 14. The stud spacing affects the ratio of insulation sq footage to framing sq footage. A 28' wall with 16" on center will have about 22 studs, not counting cripples or window studs, the same wall at 24" on center has about 14 studs. That is a difference of 8 sq ft of insulation per wall a significant amount. I'm begginning to believe that the 2x6 at 24" oc is a better way. There was an article written several years ago that claimed the 2x6 system not only was more efficient but more cost effective with regard to material. I'm tearing my office apart trying to find the article, if any one knows of it please let me know.


The most common wall insulation choices in northwest Indiana are fiberglass, blown cellulose and spray in foam. Fiberglass batts and blown cellulose have about the same rated r-value. The difference comes in the installation, any product installed poorly will not operate effectivly. For insulation to work effectively it has to completely fill the cavity, behind outlets, around penetrations and around electrical conduit. Any gaps or voids significantly reduce the effectivness. In my opinion cellulose is a much better choice than batts, cellulose is blown in and around and behind anything in the wall cavity, more often than not fiberglass batts are not installed correctly. My desire was to just give information and not make declarations but on this matter I strongly believe that blown cellulose should be the minimum standard for most homes.
Spray foam is usually a 2 part chemical sprayed into the wall cavity that expands to fill about half of the area, the rest is filled by a batt or cellulose. The best part of the foam is its ability to seal the cavity from the outside. While most foams have a higher per inch r-value the best part in my opinion is the ability to seal. Unfortunately My system designing software doesnt have the subtelty to see the variations between foam and cellulose so at this time I cant give any hints at payback time for the higher cost. This seems like enough for this post but there are some more insulation topics to cover and I will hit them later in the series