Vic, I am not sure what the upcharge would be for 8"o.c. studs.  See page 6 from link below.

http://tfinsulatedconcreteforms.com/images/stories/TechnicalLibrary/section3.pdf


Bunt

bracing hardware used for parking garages, concrete elevator towers. freeway overpasses would be very helpful ..I considered having the owner-builder rent the hardware and building the floor before the pour. but the dealer rep talked him out of it..I think haviing the floor in place SQUARE and Level would be cost effective.  2 x lumber style with the big turnbuckels used in pour in place concrete walls form sustems  would work to hold the floor in position.  .. since you will not be pouring a foot of concrete for the floor wood 4x4 posts with ellis clamps and jacks  with  temporary beams are the easiest.  We did a ski lodge in the avalanch area.. 12 inch solid concrete  walls and 12 inch roof and had to use bridge style scaffolding.  Simpson hardware is expensive compared to other options  I forget the name but the style with 2 straps sticking out and the wrap around strap and screws are cheaper.   I have a hyd press in my shop and if I did it I would build a die and pre-bend all the wrap-around straps..the homeowner put them in and didn't rent my laser and weren't as good as they should have been. the small straight wall sections around the 45 deg corners would probably be hard to brace.  I would try to build plywood -2 x 4 form panels for those areas. you can have snap ties custom made to have cones or washers in the right spots for any width wall. ...metal gripper cones and 1/4 in. steel pencil rod with hairpins  and donuts would also work.  contractors who have been in commercial concrete buildings have solved a lot of problems you willhave .

Bunt,

Thank you for responding.  To clarify, the 16" LVL was chosen to match the 16" open web floor trusses from Universal Forest Products (aka, OJ2000).  These will be hung from the LVL.  The floor system is robust.   It is 16" OC and will utilize advantech 1" subfloor.  We spec'd for L/480 floor system.  You are correct in your assumption in that the shoring at 16" will also serve as a brace.  So getting back to your concerns would slotting the openings in the lumber when screwed to the forms allow for compression?  Since the LVL's J bolt connection will be cropped this wil allow some tolerance.   Bunt, how much compression would you expect at the top course of a 10' pour?  Approximately 1-2" or less?  This is the advantage of TF.  With vertical single piece tie at 12" OC their form technically cannot settle.  Am I wrong on this?  Having spoken to the TF engineers they say the slots in the bracing are not required for their system. As such, I think that the floor prior to the pour may work best with TF since the compression issue may be moot.  

My concern with TF is their corners need external bracing.  Diagonal whalers for sure but still external.  Their 45's require external horizontal strapping about 4 intervals in a 10' wall.  Their 12" system costs more because steel tie is required.  With quadlock the tie cost is about the same.  If it were not for the corner issue TF is almost ideal.    Their biggest advantage is the fact that you can make any form by simply ripping the panel and slotting for the tie.  It is extremely elegant.

To the prior question regarding TF 8" OC, they have this now to accomodate addional form pressures from SCC mixes.  Again, you can make your own spacing by simply ripping the panels and slotting for the ties.  (you just buy more ties).  Also, the ability to erect the system from the ground up and full height with single pass is a definite plus if not a morale booster.

If the prepour, floor system, shoring concept works better with TF I might reconsider....

Again, Bunt, Manfred, and to everyone who contributes to my thread I thank you.

Leonard

Bunt,

Thank you...the idea of bearing a truss on top of the ledger vs hanging is certainly an option...definitely will save on the joist hangers. (And I have no doubt that this may be a more solid connection). I see that a 2x4 is used a rim (fits in a key) to support the subfloor between the joists. My concern is how does the finish wall look withe ledger below the floor system. It will project into the finish wall by the thickness of the ledger. How do you finish this off? I imagined that wall sheetrock will be flat from the floor system to the joists above.

With regards to the OJ 2000...they are a true floor truss. They are available in 2x4 and MSR 2x4 depending on the span. I have chosen this particular system because the wood members making up the truss are glued. They are not roll-press stapled with plates. From my understanding these rolled metal connection stamps may give with time and cause squeaks? Opinions?

Thanks again....

Leonard

Bunt,

I am sorry..I finally understood what you said that the floor is hung by "top cord." This certainly covers the LVL if it is less wide then the depth of the truss. But again, what do you think of the glued "truss" vs the metal connected truss?

Leonard

If you send me your email, I will send you some pics on Monday. I have been an independent engineer for a truss company for about 10 years now, and I have never had or heard of an issue where the metal connector plates squeak. In my region, floor trusses are basically the same $$/ft regardless of the depth. With that said I would go as deep as you can. The strength and stiffness is in the depth. The TCA recommends min of L/360 LL deflection and L/240 TL for tile. I always install floors that meet L/480 TL deflection using 65# loading. If there is stone or marble, I use L/720 TL deflection with 75 psf loading.  I also always install at 19.2" o.c unless there is some reason not to.

I actually had one instance where I installed a 14" deep floor truss system and had a squeak. There was a 3/4" subfloor, hardibacker, then ceramic tile. I finished the floor and noticed that there was one location where the floor squeaked. I thought about it for a few days, and tore out the tile and hardibacker in a 5'x5' area where I thought the squeak was. I thought possibley that the hardibacker may not have been screwed down enough. I replaced the hardibacker and the tile. After it dried I walked on it and it squeaked in the same damn place. I went in the basement and had someone walk on floor above. I noticed one of the screws I used to screw the hardibacker down protruded thu the subfloor about 3/16" and rubbed against the side of a truss plate. I took a dremel and ground of the head of the screw and the squeak was gone. This is the only instance I have ever heard of where the floor system squeaked, but obivously had nothing to do with the design or manufacturing of the floor truss.

I have been on many jobs as I'm sure others here have, where a new floor system is installed and there are squeaks right away. It seems like 9 times out of 10 the squeaks are when hangers are used and improperly installed. There are then the squeaks that develop after the house is dried in.
I see many people who glue the subloor and nail, then come back a few days later and screw the heck out of it. To me this is bad practice, the  floor needs to be screwed when the glue is still wet otherwise the subfloor is not tight to the joist and squeaks are inevitable, kinda like nail pops in drywall.

Bunt

On one of the homes I built in early summer we put the floor in first, and your right it work great. First the floor shored up the top of the system with the plywood on, it was easy to work on but working off my knees to finish it off and run the vibrator down sucked. I used the Simpsons for speed reasons. If you use the anchor bolts you will have to go under the floor after and give the bolts a couple of light hits to ensure the bolts are in and that they are encased with the concrete. We used TF on this one and did not have to use any 2x4s to hold the floor up the system held it up its self. We screwed to the plastic I beams with 3" screws (the Simpson were just in to the foam) and it held great. This floor also had 1 1/2" of light weight concrete on it after the building was done. I will try to post a pic of it with the walls set up and poured if I have any. With it all said and done the the floor can not sink because when screwed to the I beams there is no place for it to go. As far as the external braces, when you are installing it they are not really a big deal. They go up fast and with the turnbuckles to the top you can adjust them if needed when the wall is completed of the scaffold/floor. With it all said and done we will still install other systems if the customer insist, but my crews are going to keep using TF for speed, less waste, versatility, easy assembly, and all around comfort with the system. Now if I could get them to give me a better brake on the price so I could have a bigger profit margin so I wouldn't have to bid so tight on labor.

tdbuilder when you poured as mentioned above, I assume you had the ledger attached correct? If so, you mention that you poured without supporting the ledger and relied on the ties to support the joists and the plywood during the pour is that correct? If so, thats pretty impressive.

Bunt

Yes, that is what we did. I dont know what the manufactor would say about it but worked and we had no problems.

That is really impressive how strong this ICF system is.  I would definitely still shore.  Perhaps not at 16" OC but still...I think that is very cheap security.

Leonard

Tdbuilder,

This seems like a great way of putting up walls. I have two questions:

Is there any need to adjust the wall when you construct using this method? It would seem that the 3" screws into the webs and the rigidity of the joists and subfloor would make any adjustment impossible.

What is the purpose of the turnbuckles on the corners if the floor is in place?

Thanks,
Guy

You can adjust up to the point, where you start to put the trusses on. After that it is real hard to move. It still can be moved on the walls that run parallel with the trusses. The turnbuckles on the corners are for the leveling of the walls before the floor is on. You can still fine tune them after, but they have to be close at the point of setting up the floor. If you are working on scaffold you can reach over the corner to adjust them if need be. If I need to slide a panel up for some reason (like I had dropped my makita impact driver in) I can slide the outside panel up (the inside was attached to the ledger already). I loosened the closest corner turnbuckle to take the pressure off and the panel slide up nicely, then pushed it back down and re leveled it. By the way the lumber has to be some what straight, I had a couple that were twisted prttey bad and after stuggling with them some got cut up for the short runs some got returned.