Simpson Joist Hangers Using Screws vs. Ledger Boards

[kantuckid]

The task is to hang 2x8x ~ 8'L, rough sawed, Yellow Poplar & Pine floor joists using Simpson joist hangers ( LU28R-18 ), to oak 6x10 foundation beams using screws into oak beams or use ledger boards? The oak divide beams the 16 x 20 area into 4 quadrants of ~ 8' x 10'.

Cost doesn't matter so much, as screws are nearly the same cost & count either way- but the hangers do add about $8 per joist x's 24 joists=~ $200.
 
I have lots of "free", VG re-useable KD SYP 2x4's from metal roofing crates I demo 'ed. I'd screw to them to my oak beams using coated #14 timber screws in ledger boards or hangers.
 The oaks been sawed for right at 2 years, so mostly dry but exposed for now. I put wood preservative on the beams last fall as sourcing my wall logs was delayed nearly 2 years, so I also held off placing the joists or subfloor out into the weather.
 
The concern is that over time the joists would pull away slightly as the oak dries further once under a roof. 
I toyed with the idea of setting the floor frame upon the beams but decided I dislike the added height it causes so joists will go inside my beam foundation.  

Your thoughts?

[Jim_Rogers]

A 6" wide oak beam will shrink some, but most likely not enough to have the floor joist slip out of its hanger. 
I don't know the specs for that hanger, but it could be enough to compensate for the shrinkage.
You can calculate the shrinkage and see how much it has shrunk since milling and see how much more it will shrink when dry.

Good luck with that project.

Jim Rogers

[Don P]

Hanger it. Use whatever their approved fastener is. Somewhere in their literature is a slop spec. I think the hanger is rated strength with up to a 1/8" gap between joist and beam.

I'm assuming you've thought through the implications of a flush vs dropped girder with MEP, (mech, electric, plumbing). Not pushing one way or the other just thinking out loud.

[kantuckid]

I suspect these logs won't change much in width at this point other than a tad after the roof cover is there. I did shim/level a few spots a year after I'd backfilled my piers on the 10" height aspect. Was wood not soil as these are well below grade and sit on gravel below, some are based on solid rock in fact. 
 Utilities are of little factor as this is off-grid and what little wiring happens will came afterwards of assembly.  

Having all these 2x4's (I have over 250 ea around 3'-4'L and more up to 14'! I was chomping at the bit to use them!!! Then I revisited my plan and lean towards hangers now. 

Thanks for the comments! 
 
FWIW, Lowe's has a far better price point on that hanger I spec'ed, than either HD or the Amazon store of the hangers mfg.. Plus I get the 10% from vet discount with Lowe's. 
I'm throwing a joist onto the end beams for logs support and to widen the 6" base for stacked log walls and some blocking between joists on ends at beams for logs wall support and to avoid any twisting of joists. 
I've had my subfloor and joist under tarps longer than I'd have liked! No labor for floor build combined with no wall log source until recently, then the guy who's sawing my wall logs from the tree logs, got into hauling hay to TN & VA for the U of KY to drought farmers  and between that and his wife breaking her arm and nose & surgeries, yet another delay.  :( I'll be sawing and peeling logs soon so will build the floor as weather is here. Cold enough to keep my logs from bugs was good factor. 

[kantuckid]

One thing I've learned is that Mitek hangers are a much better price point! 

[kantuckid]

My deal for the day yesterday was buying Mitek connector screws, 2 7/8" torx head, used for steel hangers on sale at greatly reduced prices, even with S/H they are much less than any I've seen.
See: Shell Lumber and Hardware

Note: they don't charge sales tax! and very reasonable, fast shipping! 

[rusticretreater]

Cool, I was going to caution on using decking screws and the like.  The Mitek screws have the flat mating surface and the shank doesn't narrow at the head of the screw.  They look quality.

[kantuckid]

I'm using Simpson SD connector screws in the short, 1 1/2" version from Lowe's and 10% vet discount, but the Mitek's appear to be a screw that will drive easier in the 2 7/8" I mentioned above. Mine will drive using cordless into dry oak so I'm hoping for less battery time. 
When you begin to compare various screws, they are not all equal that look equal. 
I found it odd that apparently neither GRK nor Spax have a hanger screw. Spax in OH doesn't even answer their phones, etc. must be a have no help thing? 

[Sinoed09]

I was curious about shrinkage of the beams so I looked it up.  On average oak has tangential shrinkage of about 9.5% after drying.  If your original "green" beam was 6"x10" that means it will have shrunk by 9/16" x 1" when drying so you should have a beam about  5 7/16" x 9".  If you measure your beam today and get something close to that number I doubt it is likely to shrink any more but maybe someone with better knowledge can chip in.

[Don P]

Just general large timber shrinkage stuff. Usually a large timber is boxed heart so radial controls the overall outside dimension, but, the edges are more tangential so the faces tend to be convex. The rays tend to bind up the grain much more than the small clear samples used when developing the shrinkage tables. When you see a check, there was shrinkage but at least some of the dimension change is in the gap of the check.

[kantuckid]

The White Oak I just sawed and used all of for my wagon gear lately is in the sun and was built with straight off the saw by a couple of days. The tree had died and fallen. but still had some sap, not as much as a spring tree for sure. 
Yesterday I installed the 6 "d-rings" I bought for my straps to hold the wall logs to be toted to my build site. The wood has checked more than you'd ever expect from oak I've used or handled in the past. Every piece, heart or sap wood shows these checks? Not a structural issue, as it's hard and firm wood for sure, but still noticeable. 
My oak beams were sawn from logs about a year old with loose bark and then they were installed late 2018 as I recall. Late last fall I caught them dry and doused them with a solid exterior stain I bought from the Lowe's discount paints shelf-Olympic dark brown in a 3 gallon pail.
 I say they are pretty dry now.  

[Don P]

Bright sun, low humidity, a little breeze, it is easy to ruin some oak this time of year.

[kantuckid]

The oak I mentioned was a twin trunk tree, the first half fell across the roof corner of my shop's front extention and required some repairs. It later provided wood for a porch swing A-frame that's on our sons porch in TN. This winter while in FL snowbirding, the other half fell into the farm pond next to my shop. It leafed out last year as I knew first hand-I had an Amish crew placing metal roof on the shop and I removed a branch that pestered the job.
Breezes we got, sun sometimes, low humidity in Eastern KY :D not very often.
 I sawed it, moved it the same day via FEL forks in two loads and dead stacked in two piles under a pine tree near the hay wagon gear and shop 110v's. Then soon went to work on it, but the grain opening up seemed more than in my past experience so ya gotta have a point.
 It's getting doused with something soon as it dries out again as its rained twice past few days. I finished with one leftover 4/4 board that I tossed onto a nearby pile under a roof-it looks normal out of the sun.