I am a builder in WI and I have built with Icf block since 2002.  We do between 5- 10 houses/basements a year.  I built my last house out of ICF and sold that one and am now just about to break ground on my next home.  Now for my question.  If I use a 13 Inch block(2.5-8-2.5) in my basement could I use a 9 inch block (2.5-4-2.5) and use the 1.5 inched of bearing for my floor system instead of using a anchor bolts or simpson ties ledger system.  the floor will be I joist most likley.
                     Thanks for you replys

Yes you can, but better yet you can use a 6" core below grade, and 4" upper! Wisconsin has about the same soil conditions as Mich and we have been using predominately 6" below grade since 2000. Now that our manufacture makes 4" ICF's we top the basements last course with a 6" tapper top, and then set the rim joist on the 1.25 inches of bearing. We build the floor and deck it. Then stack 4" from basement to trusses which eliminates the Simpson hanger completely. (sorry Simpson, your hanger was a great idea even though I don't care for your new ICFVL) The ledge is carrying most of the load and we are relying on the anchor bolts (.60 ea.) for the attachment to the wall to meet IRC every 6' and also carry some of the load with the bolt even though it is non direct contact with concrete.

Dave

Think of this luxury, the framer can still walk on the ICF wall because you have screeded the top flat like a ICF basement only. He sets his rim to a chalk line with a vapor barrier between the rim and the concrete (if you feel it is necessary) and nails threw his rim into his floor joist like traditional framing. He then bumps any last adjustments around before he nails his lapping joist in the middle and then decks his joist. Just before the decking goes on he drilled a 9/16th hole in the rim and inserts his anchor bolts with the L end hanging to the exterior.

Now you are ready to stack the 4". You simply glue the 4" to the 6" after you notch in the anchor bolt head's continue stacking and poring as usual. The framers can add there joist hangers at any time, you have eliminated 500.00 of Simpson hangers, reduced your upper level cost with the 4", made the framer happy because he's back closer to traditional methods and he's not complaining about the Simpson, and he can stand on the wall!

Ok......this might be a dumb question...But do you also have vertical rebar sticking up from the 6" that will go into the 4", tying the two together? This is very interesting, didn't know you could do this with the second floor!

I have done several where I have embedded the floor joist into the ICF wall prior to pour, depending on your area you may need an individual engineer to write this up, but there is a generic detail available which is engineer stamped, but the inspector may want a job specific one.

Easiest way to describe it is attach 2x4 ledger to inside of ICF wall at bottom location of I joist, layout and cut block with keyhole saw, wrap 10m poly around end of joist and insert a minimum of 1/2 way into wall cavity, nail a brick tie to the top cord inside the ICF wall. Attach subfloor, build up another 2 courses of block and pour. DO NOT POUR more than 1/4 of the way up the joist, the liquid pressure can push the wall out of plumb and cannot be retrived when it happens.

This is not a DIY or first time ICF installer 'trick'. Walltech's idea is great for ICF crews who do not install the joists/subfloor and the first timer. Not everyone likes my method, I like it because we install the floor systems and I have a nice big deck to walk on when pouring. The bracing is still needed to hold the walls plumb in the basement when doing this. But as Walltech pointed out he just saved $ 500.00 from not using ICFLC's, I just doubled the savings not buying composite wood for a ledger board.

Robin, yes you need to tie the two walls together, whether it be with dowels from the 6" to the 4" left in during the original (basement) built or you can drill and epoxy after (expensive and usually requires engineering and inspections (witness or pull test).

Agree about the Simpsons. Although they are rated for seismic, I wouldn't use them in my own house as they must traverse all that foam. Also I am told that they can not be used in commercial work, as they can not stand up to the fire ratings, which makes sense.

Quantum, we sell them to commercial all the time and they are specified by many architects and engineers across the country.
I would have no problem using them in my house if necessary as far as failure goes. With that note keep checking the Toronto fire post, as I will get a chance to show you how well ICFVL's perform in a fire!

The fire will burn all interior walls, the floor system, and the roof. It will drop everything into the basement and not even touch the rim joist!

Dave

Quote:
The fire will burn all interior walls, the floor system, and the roof. It will drop everything into the basement and not even touch the rim joist!

Oh it's painful that people still do not build non-combustibly.

How do you do that unless you build your house like the big box stores??

At least four ways that I can think of for inter-floor decking, in order of fire-rating: post-tensioned, hollowcore, Hambro, composite (pan). And for interior walls, cold-rolled (steel) studs, not wood. Wood belongs in the forest! Steel is the most recycled metal on Earth.