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Help, please, from folks who have used TJI’s. My builder has never used them and, I suspect, doesn’t want to start now. He says that the main trunk of the HVAC (as well as all other ducting) must be suspended below the TJI’s and that it must go down the center of our basement. Without taking the foundation blocks up to 10′, this will make for an impossibly low ceiling. Is he feeding me a line because he’s lobbying for the use of dimentional lumber? If not, how do you work around this?
He also has expressed concern that the TJI’s used for the first floor would not support a second floor load. Has anyone heard of this?
FYI: this is a 30’x38′ prowed chalet with a daylight basement and 12/12 roof. The second story in question is a loft with a MB suite.
I may be suspicious: the builder told my husband that he should disconnect our cable tv. He said I watched too much Bob, Norm, JoJo, etc! I’m irked!
Thanks for taking time to help a lady in distress (or distrust).
Replies
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Kay, long time no answer. Are you working from published plans, or is this a custom-built?
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I think you have a builder that does not want to use the I-joists. I distibute and sell Boise Cascade I-joists which are competitors of TJI.
Large holes can be cut in the middle of the I-joist span, the size depends on the span of the joist and the depth. For instance, if you use a 11 7/8" i-joist, you can usually cut a 8 7/8" round hole in the center of the span. This is large enough for the flex duct to run from the trunk line to the floor or ceiling registers. The problem is with the trunk line itself. I usually try to design the trunk to run between the joists. If that is the direction you need the trunk to run then all the HVAC can fit in the floor system and no furr downs are needed. But if the trunk needs to run the 38' way it may need to be down below the floor, since holes the size that a trunk usually is are generally to big to cut in the center of the joist. But the flex duct can still be put up in the floor so the whole basement does not have to have a dropped ceiling.
As for the second floor loads, it depends on where all the load walls are. I design 2 story houses every day and never have told a person it couldn't be done.
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Greg,
Any opinion on OSB vs. plywood for the web or laminated vs. solid lumber for the flanges?
TIA,
Jerry
*Jerry - I'm not Greg, but I do have some experience with selling I-joists also. I think the OSB webs swell up more than plywood when they're wet. I doubt there's much strength difference between the two. As for flanges, it's mostly personal preference. Solid lumber flanges tend to be a bit wider, making installation of the plywood easier. But some say they split easier. Whatever brand you use, make b sureyou use span tables and installation instructions b from that specific brand. These vary greatly from one manufacturer to the next.
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Help, please, from folks who have used TJI's. My builder has never used them and, I suspect, doesn't want to start now. He says that the main trunk of the HVAC (as well as all other ducting) must be suspended below the TJI's and that it must go down the center of our basement. Without taking the foundation blocks up to 10', this will make for an impossibly low ceiling. Is he feeding me a line because he's lobbying for the use of dimentional lumber? If not, how do you work around this?
He also has expressed concern that the TJI's used for the first floor would not support a second floor load. Has anyone heard of this?
FYI: this is a 30'x38' prowed chalet with a daylight basement and 12/12 roof. The second story in question is a loft with a MB suite.
I may be suspicious: the builder told my husband that he should disconnect our cable tv. He said I watched too much Bob, Norm, JoJo, etc! I'm irked!
Thanks for taking time to help a lady in distress (or distrust).