Joist hangers vs joists resting on beam?
Yogi
| Posted in Construction Techniques on
In terms of sturdiness, is using joist hangers the same as resting the joists on the beam? Thanks-
Replies
If resting joists on a beam then you'd need a rim joist or blocking, otherwise warping or twistimg of your joists could cause them to rack, ergo not sturdy enough. Which is one thing the JHs eliminate, a plus. Did you consider tension as part of the 'sturdiness'? Joists secured at the outside ends and lapped over the beam would provide better resistance to tension than JHs. (tho I wouldn't do that at the bottom chord of an A w/out an engineer's approval). It's also cheaper that way - but that's not what you're asking. But I think where JHs win out is where the beam might protrude too much into the space below - again, not what yo...., but what the heck. So, yes and no. confused? well, you shouldn't have asked me!!
cheers
***I'm a contractor - but I'm trying to go straight!***
Thanks Piko- I'm much obliged- Dave
I don't think there's any difference if either one is done correctly. They're both fine.
I tend to shay away from flush beams if I have any input into a situation, though. That just invites the plumber or electrician to get out a big hole saw and make swiss cheese out of the beam.
Thanks for your thoughts- I appreciate it-
Are you talking about decks exposed to the weather? If so, corrosion of the hangers could be an issue.
Al Mollitor, Sharon MA
Everything was going my way til you came up with that one- That's what I get for asking guys who know what they're doing- Actually, the edge planking should keep any direct moisture off it- But yes, it's outside-
Clearly, resting on the beam is stronger, so long as the joist can't twist sideways. But there's no real advantage in being able to take, say, a ten thousand pound load when one thousand is the most you actually need. Given that, the main advantage of resting on the beam is that there are fewer ways to screw it up. If you don't screw up too badly, there's no difference.
Well, there is one other difference: In some cases resting the joist on the beam is faster/cheaper than using hangers. In other cases not.
Dan- Thanks for sharing your experience- Much obliged- Dave
In terms of sturdiness, when comparing hangers to fully supported joists (both being installed properly accordingly; i.e. full and proper nailing with hangers and blocking/rim joists with supported) I would say supported would be stronger. My reasoning would be that failure would be dependent on only the joists themselves and the beam. Hangers impart a more complicated system with more parts and a greater chance of failure. By failure I mean unacceptable sagging as well as actual rupture under load.
That being said, a properly installed hanger system will outperform any normal requirements (given proper joist and beam sizing), besides that attic garage or roof-top helipad. Choosing which may be based more on what's fastest for you to install (ergo cheaper) and also wall height layout requirements.
mbdyer- Thanks for your take on the deal- Much obliged- Reckon I'll hang 'em- Dave
Hangers resist uplift better - unless you hurricane tie it of course.
If we fail to catch a cosmic fish it may be a trillion years before the opportunity comes again
Lo these many years later, I'd like to re-visit the exact question. I am in the design phase of building our camp on the Miramichi River in New Brunswick, Canada. I have pretty much decided against TJI or engineered joists from both a cost and height above grade consideration (we are building, because of site fill) on helical piers. And heck, I'm just an old school, semi-experienced carpenter that will be building the place myself this summer.
blocked?
If installed correctly either is fine. For ease of install and less hardware on top of beam is best.
Total bearing area: On top of wood beam: 3", on joist hangers: 'fully seated' in the hanger...this means you should be seeing wood in the little 'view' hole at the rear 'corner' of the hanger, this verifies a max. 1/8" spacing from the rear of the hanger. Just one of the MANY little lessons you get when attending a Simpson Strong-Tie seminar. And joist hanger (and nails/screws) treatment varies on the wood's treatment and exposure levels, including how close it is to saltwater.