When installing ICF walls over 12' tall it takes a special techneke to get the best results. The best way to accomplish this is with the help of masons scaffolding and the way to do it in a nutshell is below.
- Build your wall to what ever brace height you have or have rented and pour to that level
- Strip your braces and set up masons scaffolding with 6 foot centers and attach to the poured wall at the top and bottom IE, bottom of scaffold and top of the 12 foot lift if poured that tall.
- You can attach to the webs with screws and bent metal to keep the masons scaffold tight to your poured wall
- Install wall boards on top of the masons scaffold, now rest the foot of your brace on the leg of the masons scaffold closest to the wall and screw to the new ICF blocks once you reach about four courses and continue to the height you want to put your stand offs to stand on
- Install standoffs like you did on the first pour and place the bottom of your turnbuckles to the last walk board on top of the masons scaffold being careful to tie the walk board down with very large wire ties (32")
- Now install the string line on top of the wall and pour as you would any other icf wall.
Take care to connect all points of stress very secure as you will be up to 20 feet in the air at this point and you don't want a failure, there are manufactures that make connections ready made for connecting the masons scaffolding to the wall and the bottom of the turn buckles to the top leg of the masons scaffold.
Good luck and be careful