If you are butting floor joists (and doing splice plates) where they bear on a beam, what do you consider as minimum end bearing for each joist?
In considering this and before you answer, think about the seat length of the joist hangers you use.
I have some joists to join over some 2-ply LVL conditions, and am mulling over whether to lap or butt and splice. Lapping will save on labor, but butting will definitely make easier the job of locating extra carrying joists where there are walls above.
Butting over a 2-ply gives me 1-3/4″ end bearing for each joist. Span max is 13′-10″.
Replies
Joist span has nothing to do with it.
end bearing should me a minimum of 1.5 "
The amount of bearing in a joist hanger is a totally different situation.
Hangers typically have nails in various configurations that help hold the weight, as well as keep the joist from slipping out.
Personally, I would never butt the things with only 1.5" Of bearing. Doesn't leave much room for error in lengths. And it sure doesn't leave much room for the joists to move in an earthquake. But that's mainly personal preference.
If you wanna figure out the minimum surface area required, figure the reaction and divide by the allowable design load in PSI.
Or check with your building department. Whatever they say pretty much trumps what any of us think.
It is better to keep your mouth shut and appear stupid than to open it and remove all doubt [Mark Twain]
Boss, I don't understand your point about error in cutting length - "not much room for"
if this is being built by the same crew that is cutting studs and rafters on the same house, how much room for error can there be anyway? More than a sixteenth inch on any of those cutts and this is going to be one hellacious looking house
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
When I talked about cuts being off, I guess I was thinking more like they'd cut a bunch of them ahead of time. I've only helped frame a couple of conventional floors, but I've never seen anyone measure each joist before cutting.
If the beam wandered at all you could end up short or long...Be willing to make decisions. That's the most important quality in a good leader. Don't fall victim to what I call the Ready- Aim-Aim-Aim Syndrome. You must be willing to fire. [T. Boone Pickens]
I would think 1-3/4" would be adequate. You could splice with 1/2 OSB for insurance.
Ideally you could get full length I joists. Is this an option?
Jon Blakemore
Bob , Code in Mass. is 1"1/2 for bearing always nice to lap if you can , Better connection !
Lapping will save on labor, but butting will definitely make easier the job of locating extra carrying joists where there are walls above.
I'm confused. How would lapping make the job of locating extra joists harder?
You just cut the one or two half on...and lap all the rest!
it's 50 times faster and easier to lap....and stronger.
There aren't any negatives.
Save your extra effort for things that matter.
FRAMING ADVICE ALERT!!!!
DON'T TAKE ANY ADVICE FROM BLUE...HE DOESN'T KNOW ANYTHING ABOUT IT. IF YOU WANT GOOD FRAMING ADVICE, JUST ASK GABE. DON'T ASK ANYONE ELSE....JUST ASK GABE!
REMEMBER, I DON'T KNOW ANYTHING ABOUT FRAMING...I JUST BS ABOUT IT.
END OF ALERT!