The only down side I found on my project using plywood and 2x?. Was that the nail fin on my windows and sliding doors landed right between the plywood and 2 by.

Another important but often overlooked point is that when installing windows, spray foam should not be used as a sealant in the installation as it will shrink over time and break loose by the window which will result in air leakage. Windows expand and contract, along with the wood framing around them, albeit at different rates due to different materials meeting together. Expandable foam tape that stays flexible throughout its life is a better method to sealing the gaps.

I totally disagree! Adhesive foams will hold a window forever. You need to use a saw to cut them out.
http://www.cid.ca/ENERFoam-ENERBOND_Canada_Spray_Foam_Insulations-Construction_Adhesive.aspx

Posted By FBBP on 12 Oct 2013 09:22 PM
I totally disagree! Adhesive foams will hold a window forever. You need to use a saw to cut them out.
http://www.cid.ca/ENERFoam-ENERBOND_Canada_Spray_Foam_Insulations-Construction_Adhesive.aspx

That foam is a much better quality foam than the typical spray foam can stuff they sell out there in the States. What stands out is that the foam you referenced:

"The foam expands only enough to generate an effective seal, retaining elasticity as the structure expands and compresses." (emphasis mine)

It remains elastic and moves alone with the structure as it expands and contracts. That is key. Many cheap spray foams DO NOT move and when the structure moves, the foam will crack and gaps will form. That latter type of foam will cause future air leaks but the foam you referenced is a better quality and it will not cause leaks.

Posted By Lbear on 12 Oct 2013 10:11 PM
Many cheap spray foams DO NOT move and when the structure moves, the foam will crack and gaps will form. That latter type of foam will cause future air leaks but the foam you referenced is a better quality and it will not cause leaks.

Anybody building with ICF and knows his stuff won't be using cheap spray foam from Lowes or Home Depot. It's way too expensive!!! Use commercial gun foam where the can screws into a separate spray foam gun. One can of that stuff is equal to about 10 cans of the big box stuff.

I was just thinking about this ratio the other day and my estimate is that it is about 2.5X, gained primarily from having a rigid nozzle, the ability to stop and restart the flow without clogging and the knowledge that the "commercial" foam costs about 3X per can.

We have also used timberstrand for window and door bucks with success. It stays put.
We have pre ordered #1 PT buck material, by the bunk, with success, as it is far higher quality and lighter.
We consistently have a $5 pump up weed sprayer on the job and spray the outside of all assembled window bucks twice with green concrete sealer/water seal product.
If one likes, a 1/2 hp router with chamfer/dado bit will provide a relief cut in the center of the back of the 2by wood buck material; this reduces the tendency for wood to warp, also a better seal and mechanical attachement to the concrete.

Eliminating dimensionally unstable wood products by using foam bucks sounds like a reasonable solution. Not as durable but a solution none the less.

If exterior wall are to be finished in EIFS and you want your windows placed in center of wall buck what product or methods would you recommend?

My reason for moving the window to center of wall is to eliminate the exterior foam trim require to cover window attachment flange.