i want to use the rp watkins hangers on my icf house.   i'm curious as to what you do in between the joist on the ends so as to have something to screw the subfloor to.   i keep looking for a description of this or some pics but so far nothing.  thanks.    

I have heard that guys have used a metal 'L' angle used in drywall/sheetrock installation and set it untop of the joists and butting up to the exterior wall. Never done it myself. I always attach rim board with AB's before I pour, but thats another story........
Paul Stevens

Install simpson ledger connectors prior to pour every 5' or so. Screw rim to ledger connector before installing subfloor. You can then screw subfloor to your rim.

sorry i'm not explaining myself well. the watkins hangers are a U shaped joist holder that is installed prior to the concrete. the i-joist then sits down in the hanger. that means there will be no rim board at the ends of the joist and so there wont be anything to screw the sub flooring into at those spots in between the joist. i've heard it called "blocking" but i don't understand what you would nail or screw the blocking to.

Once you have placed your 'I' joist in the hangers place the 'L' channel on to of your joist. One part of the 'L' will be on th joist and the other side will be up against the ICF. Use drywall screws to secure the 'L' channel in place. This will now support your first row of sheeting at the outside edge.
You could also cut 2 X 4's to fit in between the joist and screw to the web's in the ICf. I have done this in the past and it is very time consuming.
Hope this clears it up a bit.
Paul Stevens