What is the best way to insulate rim joists with EPS and batts?

Steve J July 18, 2019Updated: Aug. 4, 2020

I'm trying to insulate Rim joists /cripple walls in basements have read about three methods using EPS & batt with slightly different orders. Plan to insulate concrete walls with 2" of EPS, with 2x4 framing (filled with rockwool batt), and then drywall. Which one of these approaches should I use? 

1) Sandwich multiple EPS pieces againt rim joists/cripple wall cavities and build it out to EPS mounted against foundation wall.
2) Single EPS pieces flush against rim joist, horizontal along wood sills and then connected to vertical EPS against concrete. Batting added after framing and inside rim/cripple wall cavities. 
3) Sealing & batting first, then 2" EPS. EPS continues vertically straight from slab to below subfloor.

I have a 2-storey brick home (35 yrs old). My basement wall construction is poured concrete foundation, then a full-home perimeter cripple wall, and then joist that sit atop of it on a double wood sill. (no walkout). Foundation wall is approx 7 feet high, cripple wall height is approx 12 inch, then floor/rim joists. FYI: cripple wall has no lateral support (only backed with drywall...!?!)

Which of the three methods is best when insulating the cripple wall and rim joists?

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