EPS type 1, 2, 3 differences?
Tia M| Posted inGeneral Questionson
I’m having a hard time finding & understanding the differences between types of EPS. My general contractor ordered in a type 1 EPS foam board for my exterior walls, I just assumed & expected the pink panther and was surprised to see styrofoam sheets. I’m *zone 6a* and I was checking out info on the product (sku: 1632118 on the menards webpage/app) because it seems too wimpy to use on my walls. (2×4, zip sheathing, 2″ eps, tyvek drain wrap, furred rainscreen, lp smartside) it’s a dirt cheap product for eps and with the $ I’m paying I think it’s reasonable if I insist on better quality but i would like to have info to back me up about it. What should i know?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Hi Tia,
No need to be concerned. Type I EPS is an excellent choice for exterior wall insulation. I know it looks like cheap packaging. But, its good stuff! It's used in Alaska on high performance homes. Joe Lstiburek used 8" of it on his home. You will have an excellent wall.
2" is just thick enough for your climate and stud wall thickness so you won't have to worry about condensation build up. Also, 2" of EPS will have some meaningful vapor permeance as added insurance. A 'Rainscreen Gap' formed by placing vertical 1x4 boards over the foam makes this wall even better.
EPS is far, far better for the environment than XPS (Pink Panther).
Adding XPS to your home would be like putting EPS up as planned and then burning 400 gallons of diesel fuel in your yard just for the hell of it. :-)
Tia, one more thought... if you feel like you deserve a premium product for the price you are paying then 2" of Polyiso would be a higher quality option. This would bump up the R-Value some. But, your current wall is a good one.
Thank you folks for chiming in. You are appreciated!