Planning a DIY build, my question is how many have had success with installing ICF directly on piles and using void forms in-between the piles? Originally my plan was to build a work footing on top the piles to make sure it was level. My engineer came back with a void form in-between the piles and to set the forms directly on the piles/void form. Now assuming that the piles are installed and leveled evenly in theory it should work.?? Is this a nightmare waiting to happen or is this the "most common way to go about this"(quoted) This is a below grade basement using 8" Nudura blocks on piles. p.s i tried the search form, but gave me errors every time, so I apologize if this has been asked.

There are numerous ways to build ICF on piles:

1) Use a sacrifice footing as you describe. Be sure to have the entire footing poured on void form and the piles to extend through the footing to tie into the ICF concrete. This will allow you to square the building on a footing as normal and re-level ICF if needed. Structurally, the footing is not bearing on soil and the ICF/piles are the entire foundation. This methods work exceptionally well if you have a lot of corners (easier to square) or a high wall height to be poured (without the footing, blocks can sag between piles if pouring higher lifts).

2) If using poured concrete piles, utilize a pile cap. Pile caps can be formed with 2x4 boxes and placed on top of piles when placing concrete. Boxes should be as wide as pile and extend beyond the width of the ICF by a few inches. For example, a 12" pile with an 8" ICF (say 13.5" block width) would need a pile cap about 12" x 20". The pile cap will extend beyond the inside/outside of ICF (adding a few extra inches with the pile cap leave allowance for pile not being perfectly centered on grade beam). I prefer to laser the top of pile cap approx 1/2" lower than bottom of ICF. 2x8's are attached to inside/outside of ICF (these will rest on pile caps) and shimmed up to level grade beam. After pour, be sure to dig under each pile cap and fill will void form to avoid frost heaving on these caps.

3) If using screw piles, best method is to use sleepers. Screw 2x material to inside/outside of ICF and pound stakes on both sides of wall (leave a few inches gap- between wall and stakes) every 3-4 feet. Mark stakes with bottom elevation of ICF. Screw 2x4 to each stake at this elevation and under ICF wall (2x4 will support 2x material that was attached to ICF at desired elevation). The 2x and 2x4 can be secured with screws to straighten wall on building lines.

4) I have seen installers use a solid void form/frost cushion as a footing (leveled perfectly on ground). I feel there is too much allowance for the wall to shift so I am not a fan, but some people swear by it.

5) I know of one installer that uses screw piles, forms his ICF (stakes on each side to keep wall straight, but NOT screwed to ICF) and fills dirt on each side PRIOR to placing concrete. He claims wall is straight/level before and does not move when filled with concrete. Wet screed top to ensure level is maintained. I haven't been brave enough to try this, however.

Thank-you!

On a side note - these types of technical questions should be easily handled by your ICF supplier. If you are buying a product from somewhere that cannot help with installation instructions/suggestions, you may be wise to check with other suppliers who can provide necessary technical support.

FYI - not knocking any particular product/dealer, just a rule of thumb to consider.

Build and pour a grade beam (footing) on top of the piles, void form below, once completed build the ICF wall on top

You will not be happy trying to build a basement wall presumably 8' high on top of void form - and not have an issue

Just out of curiosity - why void form for a basement wall? You should be below frost, not sure why void form is needed, normally only use it when poor soil conditions and not below frost.

Great questions and answers. I was never aware of these options.

the site must really have to have crappy conditions. Searched and found this site with some videos.

http://www.cantsink.com/videos

cantsink dot com