There certainly are a number of ways to do it. I used six 8" blocks and one 6" block in my first pour. I attached the 12" ledger to the 6" block, and poured my slab inside the forms, resulting in an 8' ceiling in the basement. I kept my forms flush on the outside, as I didn't have a way to keep the outside walls flush with a 2" step. This does require cutting the blocks to line up. I designed the house around the main floor 6" forms, and cut the basement ones to compensate. On my second pour, I used seven more 6" blocks (for 8 total) to give me ceiling heights of 9'6" with the double top plate I used.

CTSNicholas - Never stop asking questions, it's how you will get what you want, well at least closer. TOW = Top of Wall.

https://www.strongtie.com/concrete_miscellaneousconnectors/icfvl_system/p/icfvl Most hardware stores/lumber yards will carry these fasteners. If not, drop ship. It is a two piece system so it works out to cost comparative to Watkins and more time consuming, especially when you factor in all the hangers you will need to fasten for your joists. As a DIY you may find it a viable option.

As far as your comment about tornadoes and sound, you will find that there is not much difference on the first floor. Because first floor walls are required by code to have a lot more glass than some desire there is both higher sound transfer and an obvious decrease in strength at these points of glass. As far as the strength factor where there is no glass, 4" of concrete with steel will stop most debris (you will find a few extra sticks of steel is much less expensive than 2" of concrete) but in a tornado I would still recommend the basement unless the design includes a steel and concrete roof.

Pouring your walls 4' at a time is a very safe method, but comes with more expense. Should you decide to pour the ICF walls 1/2 at a time be sure you can get your ready mix trucks around the site so you don't need to pay for pumping. It will also require a bit more re-bar for added strength to hour cold joints. This is achieved by extending re-bar above the pour and tying the net section of re-bar to existing , same as first floor attachment.

The great state of Nebraska is the home of Airlite Plastics, the manufacturer of Fox Blocks in Omaha. Perhaps if you contact them, you may find an installer nearby or they may offer you on-site tech support as well.

There is no need to cut a block in half on the bottom. Figure the height that you want from footing to truss bearing. Use the Simpson ICF hangers. 7 courses of Fox is 9' 4", that gives you room for duct work and a beam before you start banging your head. From there add your floor assembly depth (joists + sub-floor) with your desired ceiling height on the next level. This will give you a figure to work to. With 7 courses of 8" on the bottom and 7 courses of 6" on top of that you should be good. remember using the Simpsons your floor height is relative, you can go up or down. Add all the components, under slab insulation, floor joist depth, sub floor, and if you want to finish at a certain ceiling height add 1 1/4" to that to get your overall height.

Make sure you price all those different hanger options. Some are very expensive and labor intensive. Good luck with your adventure you have lots of options. In my house I am now finishing I set the floor trusses on top of the basement wall 6" wall and the put the upper 6" wall on top notching the foam around each truss. The truss ends are in a plastic sleeve so not in contact with cement but are encased in cement so they are held very firmly. Cost was very low. Hanger costs would have been way over $2k on my job without the labor.

ronmar - The Corbel Ledge would give me more meat for my I-Joists to sit on. The ledge, along with 2" reduction in form, should give enough load bearing concrete. I'd love to see a few pictures, from above, and from below. The idea sounds practical but I am wondering how a.) the corbel ledge looks on the interior of the basement and 2.) how you finish that basement wall. I would not be using 4x2 trusses...just standard 11-7/8" I-Joists.I'd just need some fastener to prevent the joist from being able to roll sideways.

jdebree - So if I am doing my math correct, you attached a 12" (assuming 2x12?) ledger board 4" up from the bottom of your first 6" core block. I assume you cast in some anchor bolts or j bolts on horizontal to mount the ledger board with? Then, you hung your joists on this ledger with standard joist hangers (affordable), and then laid your flooring over the joists, making sure each joist was flush with the top of the ledger board to ensure the flooring was level, or at least flat. Did I make any mistakes on that picture in my mind? I don't know how you would end up with 8' ceiling if you mounted the ledger flush with the top of the 8" core block, as that would mean your floor was flush with the *base* of the first 8" core block, but as you said it helps lock in the walls, so I'm picturing your ledger board 4" high up on the 6" core block. This would also mean your next course of 6" core block was set flush with the top of the joist/ledger plane. At this point, that is my best idea I have came up with. But you mentioned having to cut the block to get things to line up, and I'm not sure what you cut. Do you just mean a length difference between 6" core and 8" core blocks, or what was it that you cut on the basement blocks?

Joe - Thanks. I kept finding that bracket but could not figure out for the life of me how it held a ledger. Turns out that's the initial piece used for rigidity and the second bracket just uses that metal as an anchor point, eh? I can see it being beneficial if you want flush mounted anchors on the ledger, and saving the time it takes to cut plywood scraps to hold anchor bolts in place. Does it offer better support than an anchor bolt? I'm thinking I have more time and money, so I don't mind taking more time to make a mounting system. I assume that never would fail in concrete, the anchor plate? No reaction, and probably recommended to run something through the two hole that are inside the icf wall to add extra pull-out resistance?

I would not stay upstairs in a tornado if I was aware there was one. I'd just like the added protection to my home by having the concrete walls over a 2x6 or 2x8 timber framed home. The insulation alone should be my driving choice, but instead I am looking for more than just that...so noise and weather protection are heavy hitters on my decision making. 4" just seems like it would not be adequate if going for the rigidity of the concrete system. Thoughts? If I saw a tornado, I'd have my butt in the basement asap. lol. I do not plan on having a concrete or steel roof. I will use truss ties, somehow (haven't figured out how they will mount with the ICF wall and no framing) and perhaps a hip roof if budget allows it instead of a gable roof.

If I have to hire a pump truck for each pour, I won't be doing 3 pours! I am picturing a standard run of trucks for the footings and for the first pour if it were 4' or maybe even the 11'4" pour. But after that, I'd have pump truck. My only concern with the 4' first pour is the cold joint, but I have been reassured that you all believe as long as I have enough re bar sticking up, I shouldn't worry about the cold joint, yes? I am in touch with Fox Blocks, but haven't heard back lately. Plus, I like getting the outside expert opinion and not just one or two people trying to sell a product. They are good people, though.

emmet - That's good advice. Assuming I use those anchors, too. I don't mind having a baffle that is 7' 2" as long as it's against a wall. The rest of the ceiling would all be 8' which I am happy with. The round ducting is the only thing that would jut below the joists, along the LVL or Steel beam for the open living area. The rest of the rooms would have a support wall down the middle of the home.

newbostonconst - that's a clever idea. Good thinking with the plastic to prevent capillary action. It would work even better for me with 8" basement. I suppose that's the most cost effective way, cutting the foam for each joist to rest in. You'd have to set the joists prior to pour though, yes? To get them to fit perfectly in the pocket.

Nick- The Simpson strong ties are labor intensive, expensive, and they also allow for a point of thermal bridging. They do require some engineering for proper spacing. After that I can only say that we have not heard of any failures to date. Be careful with the removal of foam for bearing as this also becomes a point for thermal bridging and even moisture problems. There is no such thing as " never fail " as all matter constantly decays, so what to look for is what is currently best for your application. We did assist another ICF company, a friend of mine, that bolted a ledger board to the basement wall prior to pour.The process they used was to screw the ledger board to the wall using the attachment medium in the block and then drill holes and install anchor bolts from the inside, placing the nut with washer on the out, and tightening after the concrete was set. This may be possible for you as time is not the enemy in your case. It also serves as a great wall stiffener for the pour and allows you to set your height where ever you want. Can't say enough that the important thing in DIY ICF is to over brace for the pour! This would be an inexpensive option to allow for the 6" first floor without greatly compromising your insulation value, although the anchor bolts themselves are still a point of thermal bridging but with any of the systems the wood flooring system can be removed and the anchor reused should you live that long.

The basement wall was poured and left flat on top. The floor truss sits on the top of the basement wall and then the first course of foam for the upper floor wall is notched around the truss with a hand saw. Spray foam as needed.

There is no magic bullet. I like the Simpsons. I have not experienced a significant amount of thermal bridging, although, I am sure it is present. In most residential applications they are 48" O.C. on the bearing side. They are about $22 for both pieces and they install easy. Some people champion a brickledge, these work on top cord bearing floor trusses but brickledge block are expensive. I think the Simpsons are the most user friendly.

CTSNicholas check your inbox

I'm going to sound like a broken record but the Watkins Hanger is what I use.. It gets rid of the ledger and joist hangers and cost under $14. They do have a ledger hanger if that's your thing. CTS get some help from your distributor.

Posted By CTSNicholas on 08 Dec 2016 09:45 AM
ronmar - The Corbel Ledge would give me more meat for my I-Joists to sit on. The ledge, along with 2" reduction in form, should give enough load bearing concrete. I'd love to see a few pictures, from above, and from below. The idea sounds practical but I am wondering how a.) the corbel ledge looks on the interior of the basement and 2.) how you finish that basement wall. I would not be using 4x2 trusses...just standard 11-7/8" I-Joists.I'd just need some fastener to prevent the joist from being able to roll sideways.

The reduction at the corbel gives a very large support area and rated at 2000# per linear foot load capacity. The inward corbel really works best with top hung 4X2 trusses. Done this way, you won't see the corbel at all as the truss hangs down over it. I did remove a small wedge of foam at the bottom so the basement ceiling and wall will meet at a right angle, but it is dead easy with a skillsaw and a jig I made for my hot wire power supply. Pour day was very easy, even with HETA tension ties to imbed in the top course(seismic zone engineering requirement to tie floor to wall). We just trowled the corbel flat and filled the 1st course of 6" on top of the corbel 1/2 full. I was right behind the pumper pushing in the ties to correct depth as they topped off the wall. Here are some pics on photobucket.

Here is a topside view:

floor truss top

Here is a view from below.

bottom view

And another.

another basement view

You are correct; the top of the ledger is at the top of the first course of 6" block, using 12" of height. Since the slab is inside the bottom row of forms, you lose another 4" of height. I had to cut the 8" blocks because Fox Blocks do not line up on the outside when transitioning from 8" down to 6". I wish that they made a series of blocks that line up on the outside instead of the inside. Because of the way I built mine, the 2" step on the inside was of no consequence, and in fact created a nice chase for running wiring.

However you decide to hang the trusses, ronmar's use of 2x4 trusses is spot on. I was planning on using I-joists with a beam to span 31'. The final draftsman I had revising the plans suggested I use trusses instead, eliminating the beam but also importantly, allowing me to run ductwork, plumbing and electrical without having to furr down. I did have to insert ducts and sewer/vent pipe as the trusses were installed however, because at 16" OC, there is only 12"+ between the joists, too small to fit anything of length in afterwards.

I used 18" deep 2x4 open web floor trusses set on 24" centers with 1-1/8" Advantech tongue-and-groove floor decking for the floor system over my basement. This made for a very solid floor system. The trusses were 32' long with a load bearing wall near the middle at 18' from one end and 14' from the other end. I was able to run all of my ductwork (some as large as 12" diameter round), plumbing, and electrical through the trusses (I had one end of my trusses open where they intersected with a basement 1 car garage with the trusses running the opposite direction). These were top hung trusses resting on a treated 2x4 plate on top of the inside edge of the 8" ICF core basement wall. I used a taper top block for the top of the 8" core wall to allow the concrete to be approximately flush with the inside edge of the ICF at the very top edge of the wall. I had a piece of 1/2" rebar placed in the tapered edge of the form (under the 2x4 treated plate) with 3/8" rebar stirrups hooked to a piece of 1/2" rebar on the opposite side of the form. I secured 1/2" anchor bolts to the inside of the 1/2" rebar with wire ties. I then poured the 8" wall flush with the top of the forms with tape over the outside foam to keep the concrete out and facilitate installation of the 6" ICF forms for the main floor. After securing the 2x4 plate, installing the trusses, and installing double 2x4 blocking between the truss ends on top of the 2x4 plate, I wrapped the exposed wood with heavy plastic and set the 6" core ICF forms on top of the 8" wall which required cutting the inside foam to fit over the 2x4 treated plate, double 2x4 blocking, and double 2x4 top chords on the truss ends (~4.5" cut off the inside of the 6" ICF forms on a table saw). I held the 1-1/8" floor decking back sufficiently from the end of the trusses to capture the 6" ICF inside foam.

We have done over 40 houses with 6 inch core continuous basement and first floor. Central missouri. Clay and Loam soil. No structural issues. Oldest house 20 yrs old. We use icfvl connectors and georgia pacific I joist and lvl ledgers.

Are you using any "dead men" on your basement walls? And... why did you use 8" blocks on basement, and 6" on the above ground walls where you actually need as much strength and insulation? Costs factor would not be a big increase.

( We built ICF 8", apx 5K SQ FT, 2 story-inground walkout front side, ICF-poured up over the gable ends with 20"x7"x80' in pockets saddled at gable ends)