How do I transition from ICF Fox Block 8" in basement to ICF 6" above grade. I'm not sure how to make this work with the floor joists on the inside. I'm keeping the ICF flush on the exterior and I'm trying to maintain a 10' basement height. I don't understand how to handle the 2" gap on interior of the house. Any suggestions would be greatly appreciated. Thanks.

You would install the joists and then trim the 2" lip flush with your joists. Either before you install your joists off of your control line, or after. Then your decking goes over the foam flush to 6" block. It gets hidden in the trusses so to speak. If you need a picture let me know.

How are you supporting the floor joists? If it is with a ledger board, place the top of the ledger even with the top of the 8" block. The top of the floor joists should be flush with the top of the ledger. Just extend the subfloor out across the ledger and that foam lip to butt up against the 6" block...

The issue you will run into with the stepped transition is trying to route wiring up past the ledger and the step in the ICF. There are 2 ways around this. If you know where you will need wire transitions, you can pre-position conduit elbows that go thru the ledger(between the joist locations preferably) out into the 8" CC and then turn up into the foam in the 6"(conduit flush against face of the 6" CC). You can mark their location real well and cut into the foam to reach the top of the conduit after the walls are poured. the second way is simply to route all the wiring up thru internal walls and run them out into the 6" ICF wall foam...

I placed my 12" ledgers a few inches above the top of the 8" blocks. I did this to maintain an 8' ceiling in the basement. I went 7 courses of 6" block, resulting in about 9-1/2' ceilings on the main floor. For electrical, I cut an access hole in the basement, right below the ledger, and directly below the outlet opening upstairs. I then heated a 1/2" ball bearing red hot, and dropped it in the outlet opening. It comes out in the access hole 15 seconds later. Place aluminum foil in the lower hole to catch the ball, or lose it forever. The gap below the ledger created a nice chase for wiring. I can post pictures if none of this makes any sense.

Could you please send a picture? Thank you!

All this nonsense over brick ledge blocks. This is the 21st century. I've written this before. Use Watkins hangers there about $14 each it lets you install your floor joist without a ledger and joist hangers. You guys are making your job a whole lot harder and more expensive to boot.

Smartwall I was going to use Simpson. You like the Watkins better? My issue is not how to install the floor joist but how to handle the gap where the 6" ICF steps back from The 8" ICF. Do you simply pack it out with wood or cut an additional course of ICF down so the floor joist are level with the top of the 8" ICF and not stick above? Thanks for the help.

Posted By smartwall on 20 Apr 2017 02:14 PM
All this nonsense over brick ledge blocks. This is the 21st century. I've written this before. Use Watkins hangers there about $14 each it lets you install your floor joist without a ledger and joist hangers. You guys are making your job a whole lot harder and more expensive to boot.

Unless I am completely mis-understanding the OP, He is not using the brick ledge/corbel... He is using 8" ICF for the basement and 6" for the main wall and is trying to get his brain around finishing out with the 2" difference in wall thickness...

He didn't specify how he was hanging the floor... Watkins hangars would be another way, but you still need to deal with the 2" wall transition...

More expensive? At 16" O.C and $14EA(not including shipping) that is about $10.50 per LF of wall for Watkins. But you have to cut and fit blocking between those if you want a subfloor edge nailer right? DO you have to brace them for the pour/consolidation?

Using local prices in my area I could have a 2X12 ledger j-bolted into the wall with 2X12 hangars @16" O.C. For around $8.25/LF with no bracing or edge blocking necessary...

We use scraps from framing to fill in the gaps with the wood screwed into the webs. Less time with the Watkins hangers versus j-bolts and joist hangers. Even for a DIYer, time has a cost. If your transitioning from 8to6 the foam will hold the hangers. The other reason I like them is that they can be left out of the pour until you reach the top. The less crap in the form the greater the chance that you will get a no void pour. Segregation is a real problem with icf pours.

Here's a link to one of my build threads that shows the process. It's on page 4, a couple of pictures down in the first post on that page. You can scroll through some of the other pics if you want to see my DIY build.

http://www.diychatroom.com/f49/mostly-diy-house-barn-352122/