Posted By Alton on 04 Dec 2011 05:41 PM
Arkie6,
...We have considered using Simpson Strong-Tie clips in the ICF wall but prefer a ledge more so for 4x2 floor trusses or TrimJoists. The Simpson method requires three clips on each end of a truss.
In order to avoid having a brick ledge to the inside, we are considering Dietrich Trade Ready Joists and Steelform joists. I do not know which steel system will be the least expensive until we get quotes. At least with the steel joists, all we have to do is attach a steel channel to the East/West walls and then screw the steel joists to the channel. A brick ledge would not be needed.
If we go with steel joists instead of wood floor trusses, then the question becomes whether to use bolts or ICF clips to hold the c-channel to the side of the wall. If we use bolts, then it would probably be Red Head Large Diamter Tapcons installed after the concrete has set.
What would be your preference?
I don't have any experience with steel joists and have never really looked into them, so I can't provide any input there.
General practice around here is to use wet set or pre-set J type anchor bolts whereever possible due to lower cost, quicker installation (no holes to drill in the concrete), and higher confidence that they won't pull out or crack the concrete if near an edge.
For my home I wanted the ability to run all of my mechanical equipment through the floor system over the basement so I elected to go with open web engineered 4x2 floor trusses. These are designed and manufactured here local to me so that made the decision easier. I also looked at the Simpson ICF connectors for holding a ledger board to the walls, but ultimately decided to use 8" walls in the basement with 6" walls on the main floor. For the cost of the Simpson ICF connectors, I could increase all 4 of my basement walls from 6" to 8" core. I felt that was better use of my money.
The top of the 8" basement walls have a custom made taper top that I made on the inside and I have a full 2x4 plate secured on top of this concrete ledge with pre-set J type anchor bolts. The floor trusses are top chord hung and hang from the plate on top of the basement wall. You may be thinking "how does he get a 3.5" wide ledge to accommodate a 2x4 when the difference in width between the 8" wall and 6" wall is only 2"? For the 6" wall above the basement wall, I will cut off part of the inside foam to go over the 2x4 plate and double 2x4 top chords of the trusses. This also allows me to put a 1" strip of foam board on the inside of the wood to keep the concrete from the upper level pour from touching the wood. See sketch below.
I like the pre-set J type anchor bolts. I secured mine to the ICF ties with wire every 4' OC and 2" from the inside edge of the ledge prior to the pour. I put a piece of duct tape over the threads during the pour to keep concrete out of the threads. After the pour when it came time to set the 2x4 plate, I ran a string line down the top of each wall where I wanted the inside edge of the plate to be. I then measured from the side of each anchor bolt over to this line and wrote that measurement with a sharpie on the concrete next to the bolt. I then set the 2x4 plate in its position on edge next to the anchor bolts and marked a vertical line on each side of every anchor bolt to define the bolt hole OC spacing. I then layed the 2x4 flat and used the measurements previously marked on the concrete +1/4" to determine how far from the edge of the 2x4 to drill my holes (5/8" hole for 1/2" anchor bolts) and used a combination square adjusted accordingly to make my marks. After drilling the holes, the 2x4 plates dropped in place over the anchor bolts. If using this method, it doesn't really matter how well aligned your anchor bolts are - the end result is that the wood plate is positioned properly. I also ran a couple beads of F26 on the concrete prior to setting the treated 2x4 plates to help fill in any voids and help lock them in place.
