Has anyone built a basement using IFC'S for the walls?
Any thought on the cost of the ICF'S for a 20 x 32 basement?
Any thought as to how much concrete would be needed for this?
Any how much that would cost?
I have worked on a few ICF projects - not totally done them myself.
My cousin once recommended these - less waste than other brands as they arfe reversable.
http://www.rewardwalls.com/
Here is one I am not familiar with with pricing.
http://www.foxblocks.com/product_info/pricing.shtml
Round it up for estimating to $3.00 or more per square foot. 832 sq ft x 3 = $2496 Shipping - probably 1 to $2 per mile per truckload rough guess.
Concrete - depends on wall thickness - 8" is common for basements - so 27/.66 (8") =40.9 sf per yd or 20.34 yds x $125 per yard here - $2542
That does not include bracing materials or anything else -reinforcing steel - grading - excavating - footings - engineering - backfilling - anchor bolts - waterproofing - french drains - thimble board (Mira drain) etc.
Any thoughts about using ICF's for a grade beam / rubble trench foundation?
Comparing with fully-grouted concrete block (specifically speed blocks) and rigid sheet insulation:
832 sq ft = 936 16"x8"x8" blocks @ $2/block = $1900
Concrete - maybe $1500 (less needed because the concrete blocks are about 1/2 of the volume)
The forms Glenn priced are R24, which is about 4" of Polyiso insulation board @ about $1/sq ft for 2" board
So $1700 for insulation (and I think polystyrene is very similarly price per U)
Mortar - $100
Most of the other stuff should be the same
Total $5200 - almost exactly the same (not really surprising - it's mostly the same materials just delivered in different forms).
This is the way we are going for our crawlspace for a 20x30, but with less insulation as we're mostly sub-grade (more like R12, according to my un-plan-checked calculations).
http://gallery.me.com/davidj270#100036&bgcolor=black&view=grid
It seems to me that the difference between concrete blocks/rigid insulation and ICFs are subtle and mostly involve the type and amount of work involved rather than the quality of the final product. This is a big deal for folks who do this for a living, but the issues are very different if you're only doing it once in your lifetime. And for a complete amateur that gets a bit twitchy when $1000 of concrete is being sloshed around, the concrete blocks seemed just a little less scary.
(I would guess that the monolithic pour with the ICFs would be stronger, but a fully-grouted, steel-reinforced 8" block wall is probably more than good enough for many cabin-like applications - but talk to an engineer!).
Thanks for all the info.
Vibration must be used to prevent bridging but excess can cause blowouts.