Exterior wall polyiso worth it?
I live in central Texas and I’m debating whether adding 3/4″ Polyiso to the outside of my exterior walls. would be worth the cost. I originally planned on it, but since my wife and I are doing the majority of the work, it has come down to just not having the time (we both work full time jobs, plus a bit more), and the initial cost of it.
The polyiso I have been considering is the R-Max R5 3/4″ Polyiso. It is $14.95 a sheet at the local hardware store. I need at least 71 sheets of it, which comes out to a little over $1050. I would then need to tape the seams and seal everything in. My walls are currently taped at the seams and I have the Tyvek housewrap applied all around. I will be doing open cell spray foam on the underside of the roof, as well as the walls (though I’m considering dense pack cellulose as well). I did install 3 inches of polyiso on the roof since I got a heck of a deal on it and I didn’t think it would take a long time to install (entire roof took 2 months, and my roofer is still installing metal). I am already planning to install a rainscreen since I purchased galvanized rainscreen material already (not to mention the many benefits it brings to the construction of the house).
My issue at this point is that it would add to the cost of the house (building the house with cash) and it would add, what I assume would be, an extended amount of time. I am hoping that someone will give me a pretty one sided answer so I can just go that route, but with all of the research I’m doing, I keep swaying back and forth.
What are your thoughts?
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