Monday :: 08 February 2010 :: 05:35 PM
320 days to Christmas!
Mountain Air Heating, Pinehurst, Idaho 208-682-3710
ICF Hanging Ledgers
Working with Insulated Concrete Forms can be a challenge. One of the greatest and probably the most crucial challenge is your method for installing ledger boards for a second floor joist system. I have seen people prop the ledgers with posts or build walls under the ends of the joists. But this is a waste of time and expense -- you will use a lot of lumber, which is one thing you are trying to avoid by installing concrete walls.
Another method I have seen is inserting bolts into the concrete wall head first and have the threaded end hang out, or poke out from the form. The problem with this method is most bolts will corrode in time, but even if you use a bolt that will not corrode, you will spend a great deal of time lining up the bolts and drilling the holes in the ledger.
The method I have used most is the Simpson ICFLC and ICFLC-W. The ICFLC installs in the wall. The best way to assure a good installation is to use a laser level to shoot in your corners, then chalk lines from corner to corner. Then layout the ICFLC hangers according to your engineer's specs or default to sixteen inches on center. Cut a slot in the form, using a knife and insert the ICFLC.
There are two holes in the ICFLC - slide a grade four or grade five rebar through each hole. If you tie the rebar properly to the ICF struts near the hanger, the hangers should hold firm to the forms without using other measures. If necessary, other measures to hold the hanger firm to the form would include screws, duct tape or braces.
After you have poured the concrete, using care not to disturb the hangers, and/or using measures to assure the hangers are returned to a position firm to the form, allow it to cure for at least a day. I would wait three days because you would have a stronger cure. Now, using the marks from the lines previously set, install the hangers with the ledgers intact.
The best method to install the ledger is to use lumber to elevate the ledger to its proper position, propping it up at both ends and temporary nailed in place. Then insert the ICFLC-W hanger to wrap around the ledger, the smaller lip reaches around the back of the ledger and the large face wraps around the front. There are six holes in the ICFLC-W hanger. Use Simpson #5 Self-Drilling 1/4-28x3" screws (or longer if necessary) - DO NOT USE SUBSTITUTES AS THIS IS AN ENGINEERED SYSTEM. The self-drilling screws will drill through the hole in the hanger, then through the ledger and into the ICFLC hanger which anchored to the wall.
Of all the systems I have used, this is the fastest and the strongest system by far. This photo illustrates a completed system, the ledger on the right is a rim joist ledger and does not need as many anchors. The ICFLC-W hangers are shown here and the attachment should be self-evident. The ledger on the left is load-bearing and more hangers are necessary. Mounted over the hangers are the Simpson joist hangers for the I-joist floor system.
Simpson has done a fine job engineering this system. If you use it, you will save time and money -- although saving money and insulated concrete forms are an oxymoron!
Random Humor: Another Bureaucrat Joke
A Texas cowboy was working his herd in a remote pasture when suddenly a brand-new BMW advanced out of a dust cloud towards him. The driver, a young man in a Brioni suit, Gucci shoes, Ray Ban sunglasses and YSL tie, leans out the window and asks the cowboy, "If I tell you exactly how many cows and calves you have in your herd, will you give me a calf?"
The cowboy looks at the man, obviously a yuppie, then looks at his peacefully grazing herd and calmly answers, "Sure, Why not?"
The yuppie parks his car, whips out his Dell notebook computer, connects it to his AT&T cell phone, and surfs to a NASA page on the Internet, where he calls up a GPS satellite navigation system to get an exact fix on his location which he then feeds to another NASA satellite that scans the area in an ultra-high-resolution photo. The young man then opens the digital photo in Adobe Photoshop and exports it to an image processing facility in Hamburg, Germany.
Within seconds, he receives an email on his Palm Pilot that the image has been processed and the data stored. He then accesses a MS-SQL database through an ODBC connected Excel spreadsheet with email on his Blackberry and, after a few minutes, receives a response.
Soon he prints out a full-color, 150-page report on his hi-tech, miniaturized HP LaserJet printer and finally turns to the cowboy and says, "You have exactly 1586 cows and calves."
"That's right. Well, I guess you can take one of my calves," says the cowboy. He watches the young man select one of the animals and looks on amused as the young man stuffs it into the trunk of his car.
Then the cowboy says to the young man, "Hey, if I can tell you exactly what your business is, will you give me back my calf?"
The young man thinks about it for a second and then says, "Okay, why not?"
"You're a consultant for the GOVERNMENT." says the cowboy.
"Wow! That's correct," says the yuppie, "but how did you guess that?"
"No guessing required." answered the cowboy. "You showed up here even though nobody called you. You want to get paid for an answer I already knew, to a question I never asked. You tried to show me how much smarter than me you are; and you don't know a thing about cows...
"Now give me back my dog."