ICF's

[EastMark]

I've found land and am getting ready to have septic designed and land opened up along with building a gravel driveway. 
Plans along have been to put the TF on a slab and the ground is pretty flat so thats not problem.
Heres my dilemma....I'm thinking I should be having a basement now. It would be handy and great storage space.
What I'm wondering before I decide if I will pursue this... I'm wondering if anyone has done the math equation on one of their projects ? I'm guessing the slab now becomes the basement floor at a different elevation so thats about the same except a bit of excavating.
Whats the rough cost of the ICF's ? What number would be safe to carry for the floor that I would now need ? I wont be adding stairs but using a bulkhead only so I wont need to carry a number for another set of stairs. The footprint is 28 X 36.
Can anyone here throw a "rough" number on the increase between the slab build vs ICF basement/floor build ?
I know there are going to be variables but would love any input on this. :P
Mark 

[iffy]

I did the icf basement on the home I am building now. My footprint was a little larger and I had 9' walls. I also did the 8" thick walls using logix forms. My cost per sq ft of wall for the forms was about $4.60. For these calculations I will assume 8" thick x 8' tall wall.
Am also assuming a 24" wide x 8" thick footing.
Wall Forms                                     $4700
Rebar                         1300'                    ?
Concrete for footings  6.4 yds                  ?
Concrete for walls       25.4 yds                ?
Brace rental   21 @ $30 ea                 $610
Pumper truck (optional)                      $500
Help for one day                                 beer

These calculations are based on no allowance for doors and windows. Also, there is nothing in the estimate for door and window bucks (usually use treated wood). Don't know what concrete and steel price is in your area, so you will have to use your own numbers there. Cost of forms will vary depending on brand. Quantity of concrete will change if you go with thinner or thicker wall, or go with 9' or 10' instead of 8'.
My wife and I formed all the walls and placed the rebar ourselves, then rented a pumper and hired a crew that was familiar with this type of construction. The crew cost me $600 for 4 guys and they were done in about 3 hours.

[Thehardway]

Just built 6" ICF walls using Reward Walls.  My cost for forms was approx. $4.20 per sq. ft. of wall.  Concrete was $104.00 per yard, Pumper truck was $500.  Took about 2 hr's to pour.  My walls are 10'6" high

some additional cost in rebar and accessories.  Makes a nice wall and you don't need to fur out or insulate your basement walls if you want a finished basement.

[EastMark]

So I guess it would work out to around 10 K plus whatever a floor costs to build. Add a door/bulkhead.
Really not bad for that much storage space...plus it make running utilities easier and would be easier
on the old feet than a slab. Hmmm....... Decision time...meeting with the septic design guy next week
so I need to figure it out. ;-) Any other factors im missing guys ?
Mark

[Don P]

Interior support walls or girders for under the floor, I guess its part of the floor number but don't forget support of some type. Sump and drain  ???

[iffy]

The supplier I got my forms from suggested I do the pour backwards as to how you normally pour a basement. He said he pours the footings, inserts some short rebar, Then puts down the first two courses of forms. He uses foam in a can to spot glue the first form down to the footing, then sets another row of forms. He uses two rows to keep the wall straighter (staggered joints). The forms I used are 16" high and 48" long. I felt that two rows would be impossible to step over, or lean over to finish edges from outside, so I set only one row, but screwed down a 2 x 4 to the footings on the outside to keep the wall straight.
We then poured the floor. Reasoning behind this is, you now have a flat hard surface to work from, and your brace rods can be screwed to the floor instead of trying to drive stakes to hold the brace rods. It worked great!
I did some other things to keep my floor crew happy. I had all the prep work done before they got there so all they had to do was place and finish. That cost me $1/sf. Also, wherever I had rough-in plumbing that needed to come up out of the floor, I cut a styrofoam biscuit a little larger than the od of the fitting under the floor and taped it on to the end of the fitting. I kept the top of the styrofoam about 1/2" below finished floor grade. This allowed the crew to screed right over the top and power trowel without hand finishing around sewer pipes. I had a drawing of the basement and I marked the locations of the drains on the map with distances from nearest walls so I could find them later. Of course it rained on my map and all the ink ran, so I was using memory and a hammer to go around and tap until I found the drain. Usually there was a little depression in the floor where the drain was.
We ran the electrical in the basement last week and that was a piece of cake. I had a burner that came with my sip roof and I used that to burn out a hole for the electrical box. Then used an electric chainsaw to cut a groove from the top of the wall down to the box. Romex wire fits very snugly in that groove.
I used a lot of heavy duty zip ties to tie the forms together end to end and top to bottom. Also, try to avoid any joints that line up from one course to the next. Fill small gaps in cut joints with canned foam. If any area around a corner looks weak, screw some plywood or osb over it. Screw plywood or osb to all window and door bucks, inside and out, and lapping over onto the foam at least 6".
The day of the pour, my pucker factor was pretty high, because I could feel the forms quivering as they placed the concrete. However, all went well, no blowouts, and the adjustable bracing allows you to adjust the wall to a string line after pouring. I am extemely happy with my basement.

[EastMark]

After further review of the lot and some great info here....I am going to do the ICF basement/foundation. I spent an hour or so at the site which is merely woods now and am going to make it a walkout type even thought its just for storage and utilities.
I need to decide what type of door. I want to be able to drive the ATV's in so it will probably be a small garage door.
I obviously want it to be tight so I may get a insulated steel 48" hinged door or 36" doubles. I had a buddy with a single 48" and we could drive the motorcycles right in yet it was tight and secure. I'll have to investigate options on doors.
I assume the ICF's are not all created equal. What am i looking for/looking out for ? I think the energy star calls for R10 minimum on the foundation so thats a no brainer from what Ive seen with ICF's.
Thanks for everyones help....esp Don and Hardway. You guys are a big help to many here as are others. Great site.
Mark   

[iffy]

You're doing the right thing. You are right, all icf's are not created equal. Some give you a full thickness wall, such as 4", 6", 8", etc. Others have "pillar" cavities in the foam, and the wall is more foam than it is concrete. Some have webs made out of poly, some have webs made out of steel.
I chose to use one that gave a full thickness wall and had poly webs. Some forms ship flat and the web slides into T channels to assemble them. The ones I used were not collapsible, but I felt they were stronger. My forms have 2 3/4" foam walls and give an 8" concrete wall for a total thickness of 13 1/2". The manufacturer claims R30.
The contractor that poured the walls for me requested fly ash in the concrete because it was running thru a pumper and the flly ash made it flow easier. Ditto for flow within the walls too. The only mechanical vibration they did was in the top form and the brick ledge. For the rest of the pour they just had a couple of guys follow them around the wall banging 2 x 4 blocks flat against the wall to help the conrete settle.

[Don P]

Thanks for your posts to this Iffy, you've brought up several things I'll look into trying next time. One thing the ICF rep here mentioned was a sawzall without a blade for a vibrator. Just run it around on the foam. I've got a couple with broken shafts so they vibrated even better, knew there was a reason to keep 'em  :D

[Thehardway]

There are some problems with ICF's which use steel webs, they form a thermal bridge which can cause condensation.  Also they will rust and eventually be a path for leaks.  Make sure you use the correct waterproofing on the outside of the basement.  It must be formulated for use with EPS. Unless going up more the 2 floors 6" walls are optimum for structural strength, and thermal performance.  The thickness of foam in forms becomes important when running plumbing, wire, and electrical boxes. For this reason i went with a 2.5" eps form.  Forms which are reversible and interchangable have less waste.  Make sure you keep all the attachment points in line rather than staggered.  I braced my walls off dirt before pouring but will pour the floor and attach bracing as iffy advocates next time.  Dirt moves too much.  That's all I can think of right now.

[iffy]

Hardway is dead on right about the right waterproofing and the thickness of foam. Also, don't forget to put your pass-thru's for utilities in before you pour. I just used a chunk of pvc pipe large enough to put the utilities thru with plenty of air space left. Just cut a hole in the wall the size of the pvc on both sides of the form, cut the pvc to length, and put it in place. I used canned foam around mine to fill up the gaps, then screwed a plywood plate to the wall over the pvc to strengthen it for the pour. You'll love putting these together. It's like playing with a really big lego set.

[Jim_Rogers]

Eastmark:
Also, consider most icf forms have to be covered with sheet rock on the inside so become a fireproof barrier.
You'll need to figure that into your costs....

Jim Rogers