We are building a home in the North Texas area and have a couple of options presented to us by our builder.
Dense pack cellulose in exterior walls (2x4) and blown in fiberglass other attic wih radiant barrier on roof deck
Open cell foam on exterior walls and 2" of o pen cell foam on the attic floor with additional blown in fiberglass to bring the feffective r-value in the attic up to R44. Radiant barrier on the roof deck.
Is there any science that shows if the foam on the exterior walls and attic floor only will provide as much benefit as full encapsulation?
We don't want.to do full encapsulation simply from the aspect of cost and we are not sure how the house will "breath" with full foam. What happens when you get a roof leak. We get a damaging hail storm at least 2 times a year in my area. With a normal roof I can find the leak quicky. With foam where does the moisture go in the event of a leak?
Also with foam how to run new electrical and/or communication lines through a dense foam?
Both options get ZipWall sheathing. There is about a $3000 difference between the two options.
Am I wasting my money on the foam? Or is there some benefit to it?