In Los Angeles County the building and safety laws say you cannot fill 8 feet of an ICF wall all at once.   You have to do it in no greater than 4 foot increments. 

I am going to have #5 vertical rebar.   My ICF walls are 8 feet high on a 4 foot high retaining wall = 12 feet total.   I am wondering what is the need for bracing on the top 4 foot increment?   Do I need to have just as much bracing or will the bottom 4 feet with vertical rebar do a good job of holding things together up higher?

I am asking because I plan to use plywood and 2x6's for bracing and together with the county specified retaining wall the structure ends up being 12 feet tall.  It gets pretty high and tall and extending the bracing that high gets awfully troublesome.   I'm wondering if I can just super brace the lower portion of the ICF wall and then rely on the vertical rebar and dried concrete to hold things together up higher?

I'm confused on what you're asking. Do you already have 4' of wall in place? And you are adding 8' on top of that of ICF? Or are you pouring a 12' wall all at once in 4' lifts? When they say that you need to do it in 4' increments, I'm sure that means you cannot dump 8' or 12' of concrete all at once. They want you to pour no more than 4' along the wall at a time, let it sound off (start to stiffen, but not dry), then do another 4' lift, let it sound off, then pour you last lift. If you are using a vibrator, that will allow the current lift of concrete to blend with the previous lift and eliminate a cold joint.

You'll want your braces to be able to grab the highest course. Plus, you'll need a platform to walk on anyway. Just make them out of 12' 2x and make your waling platform at a comfortable level.

"In Los Angeles County the building and safety laws say you cannot fill 8 feet of an ICF wall all at once. You have to do it in no greater than 4 foot increments. "

Interesting regulation. That's probably because few ICF companies can prove what lateral pressure they are designed to withstand. I wonder if that applies if you can show where your ICF formwork falls in the ACI tables. Polycrete Big Block 1600 withstands 1,600 lbs / sqft of lateral pressure, so ACI tables indicate you can pour over 10ft in 70 degree temps.

For Reward Blocks the requirement is in RR25418 for BuildBlocks it's in RR25740, link below.

requirement states:

> The maximum allowable pour rate of the forms shall be 4 feet per hour

I asked my inspector about this. He was very familiar with this rule and and told me flat out he won't allow for pouring more than 4 feet at a time.

Since I'm building an 800 sq. ft. house 4 feet wall height = 5.3 cubic yards of concrete. Concrete trucks hold 10 cy So what should I do? Have the truck wait around one hour at $5/minute??? I have thought of other projects like patio slabs and sidewalks where I could use the extra concrete. Still it's a hassle. All of that has to be ready to be poured just as soon as the ICF's are poured.

Regarding the 4 foot high foundation. It doesn't make sense unless you take into account that the Los Angeles aqueduct is 120 feet away from the house and the San Andraes fault (the big one) is 1 mile south. Because of this the county said I have to build the house with 4 foot wide foundations deep underground on top of a 4 foot above grade high wall and an 8 inch thick slab. See pix on link below.

An alternative would be to make the concrete myself in small batches of say 1/3 yard at a time and fill the ICF blocks in by hand. It is alot of work to do that but I wonder if I wouldn't need braces if I do that? Also what are the implications of what you call a "cold joint"?

http://www.buildblock.com/technical/PDFs/LA-RR-25740.pdf

http://tj.jtusz.com/construction/foundations/

Posted By jacktca on 04 Oct 2011 02:20 PM...

Since I'm building an 800 sq. ft. house 4 feet wall height = 5.3 cubic yards of concrete. Concrete trucks hold 10 cy So what should I do?

Surely your concrete supplier has less than a full 10 yard load minimum?  Around here the minimum delivery charge is 3 yards.

Assuming the minimum delivery amount is less than a full load, have the concrete batch plant deliver two loads of ~5.5 yards each staggered ~30 minutes apart.

There is no minimum, correct.  They just price it so that it is not cost effective to take less than a full load.    The second load can be less than full however and they don't charge you extra.   By the way my area might be different than most because it's a ranch far away from civilization.  Anyway, I'll just get more than one full load and have a sidewalk and patio slab to pour at the same time.   I was planning on doing the pour in two completely separate passes.   Good I checked on this forum for advice.   Good thing I found out about the cold joint problem as well.   Thanx all.    I'm going to prepare the brace supports for the full 8 feet and do the two 4 foot pours one hour apart.