Chris, technically you are correct just as a 2x4 will compress axially -- but its not something you can catch with a tape measure. From what Ive seen and Ive measured it many times I have negligible compression. BTW many or most of the blocks claiming full height furring strips arent quite full height I suppose this could cause what you are referring to. I'm sure there are reasons for picking a block - I thought I should mention this because "locking fastening strips" is one of the main reasons one might chose a block. Regards from way south of 49.

Texas, run some strips of fibre tape from the top of the wall to the bottom before the next pour. Your right, it's negligible on your preferred block, but it is still prevalent, just more so in some than others and I've seen minor issues where the bucks are too tight so that area holds higher, and also sometimes it compresses more in that area causing the horizontal joint to open up. Mid wall if during the pour the guy just stands there the wall compresses more in that area if he is not moving during the pour.

The regular crowd here probably doesn’t want to hear it, but Polycrete Big Block actually does not compress. The reason is the rigid welded wire mesh reinforcement inside the foam panel (that’s also part of the reason the blocks are uniform sized – they don’t shrink when curing). The proof is that the strongbacks on your bracing don’t have to have slots in them. You can screw right through the metal into the fastening strip and nothing moves when you pour. You also don’t have to have your wall angled before pouring. Plumb it up. It won’t compress. It won’t move.

Posted By BrucePolycrete on 23 Mar 2012 09:22 AM
The regular crowd here probably doesn't want to hear it, but Polycrete Big Block actually does not compress. The reason is the rigid welded wire mesh reinforcement inside the foam panel (that’s also part of the reason the blocks are uniform sized – they don’t shrink when curing). The proof is that the strong-backs on your bracing don’t have to have slots in them. You can screw right through the metal into the fastening strip and nothing moves when you pour. You also don’t have to have your wall angled before pouring. Plumb it up. It won’t compress. It won’t move.

Nothing against Big Block,but all EPS shrinks as it cures. All ICFs can compress, even the full height ties that lock together. An installer cannot get them as compressed as tons of concrete can. Pouring into Nudura we here the interlock clicking to tightest position.

Posted By ICFconstruction on 23 Mar 2012 10:45 AM

Posted By BrucePolycrete on 23 Mar 2012 09:22 AM
The regular crowd here probably doesn't want to hear it, but Polycrete Big Block actually does not compress. The reason is the rigid welded wire mesh reinforcement inside the foam panel (that’s also part of the reason the blocks are uniform sized – they don’t shrink when curing). The proof is that the strong-backs on your bracing don’t have to have slots in them. You can screw right through the metal into the fastening strip and nothing moves when you pour. You also don’t have to have your wall angled before pouring. Plumb it up. It won’t compress. It won’t move.

Nothing against Big Block,but all EPS shrinks as it cures. All ICFs can compress, even the full height ties that lock together. An installer cannot get them as compressed as tons of concrete can. Pouring into Nudura we here the interlock clicking to tightest position.

Brad - as Bruce says, we screw to the top of each slot in the strong backs and screw tight. We have never had an issue with the screws holding up the inside face while the outside face compresses. The product we use has fully meshed plastic inserts for the webs and the webs lock together and I have not noticed any floating or compression. I have noticed size differences in different aged block, wether this is from continual curing or improper curing in the first place I'm not sure.

With resting the floor ledgers on the strongbacks, the floor always stays at the prescribed height. I use the scrap 1x to make the wall height work for standard drywall heights and to make sure the strongbacks don't get jammed in after the pour. When doing the basement and the customer wants a full 8 or 9 foot wall, we normally set the strongbacks on two 2x's to allow for the slab thickness. I find it so much nicer to have the whole floor on during the pour. You can just walk across to the other side not have to follow the wall around. You can lay the viberator and other tools on the floor and you never have to worry about passing by an overly larger employee on the planks! Also everything stays nice and straight and square. When the pour is done, you are done. No messing around straightening walls etc. The floor has to go in anyway and I don't believe it takes anymore time doing it before than after.

Back to op's question, while I like anchor bolts, I don't see why you can't do this with either Lavann or Simpson hangers. The last time I priced Simpson, I was not impressed with their pricing which is why I stayed with this system. I do note that the Lavann are close to home so I will look into them a little closer.

thanks for the replies. This is great information. I have never read nor heard about the floors being installed prior to the pour, although I have often wondered that but never asked as I thought it would be a stupid, pointless question!

If you are going to build the floor system before the pour, why not just eliminate the ledger and connection hardware altogether? Buy the floor joists or trusses a few inches to a foot longer and extend them into the ICF cavity. But first, protect the ends in contact with the concrete with a vapor barrier material. Then cut the inside foam out to fit around the joists/trusses. Rest the joists/trusses on the wall bracing or other temporary shoring. This saves the cost of the ledger board and all of those anchor bolts and joist hangers. Plus it is more secure. And if you pour and finish the basement floor prior to pouring the walls, you can use the interior framing to help provide support for the upper floor system (plus it is way easier to pour and finish the basement floor without the walls or floor system in the way).

We have done your way as well Arkie, it works but is not always acceptable. We did the radius walls on a house last summer that way, engineer approved, TJI doesn't want to warranty, even with joist protection. California engineers would never allow us to do that when I was there as they want the ledger for diaphragm purposes

you comments made me consider another issue. My floor system is designed to sit on bearing walls and not posts/beams. However those will sit on the poured slab (thickened under the walls). Is it a bad idea to set the forms, brace some from the exterior, pour the floor, frame the bearing walls, set the floor, and then pour the walls? This seems like it would take a long time to have the foam walls standing.

Maybe an extra week? That's no problem

Posted By arkie6 on 25 Mar 2012 12:13 PM
If you are going to build the floor system before the pour, why not just eliminate the ledger and connection hardware altogether? Buy the floor joists or trusses a few inches to a foot longer and extend them into the ICF cavity. But first, protect the ends in contact with the concrete with a vapor barrier material. Then cut the inside foam out to fit around the joists/trusses. Rest the joists/trusses on the wall bracing or other temporary shoring. This saves the cost of the ledger board and all of those anchor bolts and joist hangers. Plus it is more secure. And if you pour and finish the basement floor prior to pouring the walls, you can use the interior framing to help provide support for the upper floor system (plus it is way easier to pour and finish the basement floor without the walls or floor system in the way).

arkie As Chris indicates this tends to void warrantees. The TJ are designed to be bottom hung. When you encapsulate the truss ends and make both chords solid, it can no longer move as per design.

Posted By lzerarc on 25 Mar 2012 12:48 PM
you comments made me consider another issue. My floor system is designed to sit on bearing walls and not posts/beams. However those will sit on the poured slab (thickened under the walls). Is it a bad idea to set the forms, brace some from the exterior, pour the floor, frame the bearing walls, set the floor, and then pour the walls? This seems like it would take a long time to have the foam walls standing.

The alternative to slab thickenings is to pour a strip footing for the bearing wall at the same time as you pour the outside footings. Cast a 3.5" x 3" curb on top of the footing and set the bearing wall on this. ( the curb should be as high as the slab will be and as wide as the stud wall) Many contractors prefer this method as it allows the whole house to be weather tight prior to pouring the slab. Also all underslab work can be done with the roof on. This method also keeps the floor slab much cleaner.

I spoke with the rep on the idea. They have installers that do put the floor on prior, and he sent me a few good pictures of them doing so. I think that is the route I will plan on going.

FBBP and iz.....can you post pics on how this is done?

Posted By Alton on 06 Jan 2012 12:19 PM
Izerarc,

Assuming that you are referring to the clip shown in the link, then the written instructions and the video both show that a very small piece of foam has to be removed so that concrete can fill the void.  There may be another way of installing it not shown.

Actually the written instructions say that the small rectangle of foam only needs to be removed if there is high backfill the other side of the wall at that point.  ( See the little 2 by the paragraph, and comment at bottom of the instructions.)  I guess the guy in the video may be in a basement, but the video doesn't look like it!

I'm using a bunch of these later this year on a Quad-lock ICF building in Osoyoos, BC, Canada. I'll report back..