Replies

1. 
   abbysdad | Jul 14, 2008 01:01am | #1

   Hi,

   Depending on where you live (no info in your profile) there may be other requirements. Wind, earthquake, etc. Also, you don't say anything about the bearing strength of your foundation. Can the soil handle an additional 30 ton over a 24' x 24' area? What sort of support will the 6x6 posts get? There's really not enough info in your post to give you a useful review or anything close to yes or no answer.

   At a minimum, check with whatever construction standard you're allowed to use. I don't have my load and span tables handy, but the 12' OC detail seems too far apart to me for 30 ton. Depends on how you plan on connecting the posts and beams. If I were building something to hold that kind of weight, and if I expected to use the floor to hold something of value too, I'd have a structural engineer check the details before I made any firm plans.

   Best Regards,

    Chris

2. 
   coonass | Jul 14, 2008 01:36am | #2

   goatman,

   That's way too light. You need pro help on this.
   Your sizes are about what I would spec for a residence.

   KK

3. 
   FNbenthayer | Jul 14, 2008 01:48am | #3

   30 ton of feed... you gotta be the goat king!

   I'm no engineer ((you should talk to one), but, steel and concrete have a good track record especially if your planning to have a machine up there to move the feed around.

    

    

    

    

   The awful thing is that beauty is mysterious as well as terrible. God and the devil are fighting there, and the battlefield is the heart of man.
   - Fyodor Dostoyevski

4. 
   Danno | Jul 14, 2008 01:53am | #4

   I agree with Coonass--you are talking about 576 square feet carrying 60,000 punds, so that's just over 100 pounds per square foot--assuming the load covers the entire floor. What you have described would maybe hold 30 pounds per square foot.

1. 
   MSA1 | Jul 14, 2008 03:42am | #7

   Thats what I was figuring out too. Funny how no one figured it out in the first place.

   105lb / sqft is alot. I hope as I read further I hear about an engbineer being called in.

5. 
   Piffin | Jul 14, 2008 02:01am | #5

   with a requirement of over 105#/sf you need an engineer's help.
   you are way too light! I would not begin to try engineering this with rules of thumb, but I know that your design sop far is woefully short of adequate.

   The other thing that is making me wonder - is this barn already built and you are now adding a second floor inside the structure? That presents it's own problems besides the beam and joist spans.

    

    

   Welcome to the
   Taunton University of Knowledge FHB Campus at Breaktime.
    where ...
   Excellence is its own reward!

6. 
   MarkH | Jul 14, 2008 02:55am | #6

   I think you're too light. Here's some free plans you can download, see if any help.

   http://extension.missouri.edu/explore/agguides/agengin/#Plans
   http://www.cerc.colostate.edu/Blueprints/Farmbuildings.htm
   http://www.agriculture.gov.sk.ca/Farm_Structures
   http://www.public.iastate.edu/~mwps_dis/mwps_web/hy_plans.html

1. 
   Jim_Allen | Jul 14, 2008 01:31pm | #8

   Thanks for those links Mark! We don't need Boss no more becuase they have the trusses already designed in there! Every house is going to look like a storage shed for fertilizer but hey...it's free truss design! Bob's next test date: 12/10/07

1. 
   MarkH | Jul 14, 2008 01:45pm | #9

   You're welcome, I guess.They're just plans like a generic Chateau Du Luxe McMansion.
   I think they're neat plans, And if you happen to need a fertilizer shed, well, there you are!I don't see the OP hiring anyone to engineer his barn, heck he was only going to buy about a third of the lumber he needed. I was hoping he would find something to inspire him to build more substantially so he doesn't kill someone with a cave in.

1. 
   Jim_Allen | Jul 14, 2008 02:25pm | #11

   Yeah, I'm cool with all those plans. Boss is going to be ticked off though when he sees chicken coops springing up all over town with everyone building their own chicken coop trusses LOL! Bob's next test date: 12/10/07

1. 
   MarkH | Jul 14, 2008 02:51pm | #12

   LOL

7. 
   BossHog | Jul 14, 2008 02:24pm | #10

   Like others have said, I figure you're designing for about half of what you need. Neither the joists nor the beams are close to adequate.

   I once tried to be a model. But the glue made me nauseous.

8. 
   junkhound | Jul 14, 2008 03:38pm | #13

   See this is your first post and no hazing yet??  Welcome 'anyway'

   Not much eng needed, simple enought to do in head for 120 psf (nice even numbers): strength ONLY, no deflection considered - the joists below may start to sag over time - so what for a barn.

   M=w*L^2/8=SIGMA*z;

   For 12" b.c. and 12' spans

   z=10*144*144/(8*1000psi)

   z= 26 =b*h^2/6; for  2by, h>10.2", so you need 2x12s for the 12" spacing spans, you could get by with 10" 2xbs if you get #1 or better DF or SYP joists (sigma = 1500 vs 1000).

   Now the 6 by's

   2 ends of the 2x12s onto the 6by contributes about 1500# rounded up); again round up for doing in need is about 120#/inch;

   M=120*144*144/8=32K; thus for 1000pspi 6by you need z=32; h>7, so your 6X8 are barely OK - assuming the end joists are right over the posts.

   Each post carries about 18,000 pounds rounded up (6x6 post OK).

   At a very low 2000 psi conservatively for about any soil, that means your footings need to be 9 square feet!!!, thickness past what I do im my head, but rebar and 1 ft thick tapering out to 4" should do it.  You need to find your soil bearing capabilities. If you are building on a granite ledge, ya need no footings, on hardpan only a few sq. feet.

   Also, as previously mentioned, ya need to prolly beef up the wall footings. If you fill in your profile - click on your own name.

   If on wwest coast or Ohio/MO?MI confluence area, ya got a real problem for shear walls on the lower walls.  30 tons * about 0.3g = 20,000#; thus you would need 'at least' shear enough so you could hook a cable to the 2nd floor and pull with a 8 ton tractor and not pull over the barn.

   Using a calculator for this would cost you $1.2K <G>

    

    

    

1. 
   Jim_Allen | Jul 14, 2008 04:24pm | #14

   I'm impressed. How'd you remember all that? Bob's next test date: 12/10/07

1. 
   junkhound | Jul 14, 2008 05:26pm | #15

   How'd you remember all that?

   Ha, maybe about all I do remember. 

   When in 30's, could also do the support posts then in my head (just a guess from experience that 6x6 are ok), but not now (would have to open a book, but at least remember which book)  When younger, could do Maxwell's equations in my head, wier flow, duct flow, remembered the section modulus of many common I and H beams, etc.

   It's heck to get old and slow. Maybe why remember the moment formula is that I use them all the time to eyeball logs to build sheds <G>  

2. 
   DaveRicheson | Jul 14, 2008 06:52pm | #16

    I love it when he does that.

   Reminds me that there is more to it than just kicking the tires and saying let's roll.

2. 
   abbysdad | Jul 15, 2008 08:43pm | #17

   Yup, Junkhound, that's about what I figured too. But I'm not sure about the deflection part. A structure is a structure; I don't think you get too many breaks in the code for barns. And I'd be more worried about a sagging part of a floor system with 30 ton of grain on it than a sagging second floor carrying only bedrooms!

   The loading pattern and use of the second story also effect the final result. As will the connection details between the beams and the columns. 

   If he's going to use any equipment on the second floor, that's a live load plus dead load condition, and the design rules change, not to mention you have additional safety factors to account for. Because of the loading in each bay, he may have eccentric loads on the columns and footers, which would also increase the required size of the column and change the details of the footer. And all of that doesn't include further issues from wind loads, etc.

   Again, my vote is that the guy talks to a PE in his area so that all the possible uses and complications are figured out. Then everyone can sleep soundly at night not worrying if the floor will collapse.

3. 
   peteshlagor | Jul 15, 2008 09:27pm | #18

   Now what would happen if he were able to find Frenchy's sawmill?  And he was able to get 8x8's and 4x10's - or any other size for that matter?

   Is there real savings from stepping up to these other sizes and buying green wood for the purpose?

    

9. 
   Pierre1 | Jul 15, 2008 09:43pm | #19

   Your structural components appear to be on the light side.

   For a 28' wide horse barn designed to hold hay bale feed on the second floor:

   The 14' joists were spec'd by the yard's bldg. dept. at 2x12, 12"oc, lapping over a well supported mid-line beam (14 7/8 tall). Floor: 3/4" t&g plywood. Lintels over narrow windows: 3-ply 2x12.

   Plans purchased from 'horsey' or 'back-to-the-land' publishers should be checked and/or adapted to your site conditions by a competent structural person.