ICf basement forms

[new land owner]

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?

[glenn kangiser]

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.

[Source_to_Sea]

Any thoughts about using ICF's for a grade beam /  rubble trench foundation?

[davidj]

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!).

[new land owner]

Thanks for all the info.

[glenn kangiser]

Vibration must be used to prevent bridging but excess can cause blowouts.