Another bin question...

What are the concrete requirements for a grain bin? Looking at charts of sizes this weekend and wondering. I look at what I want to do with it and assess my needs and it looks like about 5000 bushel would be a good jump off point. Charts seem to put these at 18' diameter but correct me if I am wrong. What are we talking in terms of concrete thickness, reinforcing, footings, etc? Any general guidelines out there for this? Like up to "x" bushels you need "y" thickness?

Just running my numbers. Doing a little cost/benefit analysis.

I used to dig the foundations by hand and use 3/8 plywood for the forms. We usually dug down three feet. Then formed up a foot above the ground at the edge. We threw the dirt into the middle of the foundation. So the outside is thick and the inside floor thickness is only 3-4 inches thick at the middle. The footers where usually about 12 inches wide at the base. Then they would taper to wider as you shaped the top. So you end up with about a two foot wide heavy section at the top of the trench. Then you fill the middle to where the floor is only 4-5 inches at the side tapering to less in the middle.

I always started by driving a four foot long 1/2 pipe in the center of where I wanted to build the bin. Put the top of this pipe at the height you want the center of the floor to be. I usually made the center 1-2 inches higher then the outside so any water would run away from the center of the bin. One inch is enough for bins smaller than 28 foot. Go up towards the two inch mark as they go bigger. So if your building a 18 foot bin I would make the foundation 20 foot. So you would need a straight 2x6 longer than 10 foot. On this 2x6 I would fasten a 1/2 rod that would drop into the 1/2 pipe making a center pivot for the board. So with just a level on top of the 2x6 you can set your outside forms and the level of your gravel under the center concrete. You also use this board to screed off the concrete. With a mark on the board you make your circle for the dug foundation and the shape of the outside form. IF you have the dimensions of your bin then you know where the anchor bolts need to go. Put another mark on the 2x6 and you can set them as you screed the concrete off.

I have moved and built 15-20 bins in my life. We usually could dig and set the forms in one day with three men working. This was all by hand. The smaller excavators where not known back then. We would pour then the next day.

It will vary depending upon the size of bin- not just bushels, but height of grain- and you might find multiple combinations of height and diameter to meet your bushel requirements. Tall and narrow might mean less total concrete, but short and wide is generally easier to move air through and dry stuff with.

The last bin we built was relatively small (30' x 9 rings, not quite 15,000 bu) to use for cooling out of the dryer. The pad was 2 foot thick around the outside, and I think 6" or 8" in the center. You can set them lower to the ground, without the wall, but there can be drainage issues in locations with those (you don't want a flood to enter the bin!) and it limits the options for unloading augers.

I'd talk to a dealer. It won't cost you anything to dream big. And before I bought a used bin, I'd want to know what a new one cost. The dealer can give you specs for the floor, and will have a good idea how much re-bar you need.

As far as cost benefit goes, I think you will find it won't be free, but has a much greater return than anything with rubber tires.

A wise grain market one said, "You are either going to pay for your bin, or someone else's." It might as well be yours, and not the elevator's.

JD Seller's ideas are all good. One thing that I would add is to use #9 wire (maybe 3 of them) around the outside of your forms so they wont pull apart.

I did that for my 24 footer, used 3 fence stretchers to tension each strand (left them in place during the pour) and fence staples to hold the wire in position while I tensioned it up. You can't get far enough up out of the ground for the unload auger....just saying...

Dave,

I have built several bins and used a similar approach as to what J.D. suggested except. First I bulldozed off a flat area where I wanted the bin and then I used a ring of the bin for the form plus a three foot additional section so the cement will have a greater circumference than the bin. This extra section will be where you want the discharge auger to extend through the cement. Wipe it with drain oil so the cement does not stick to it and you are home free. In the center I always used a fifty five gallon drum and cut the top out and weld in a six inch piece of channel iron with the 1/2 inch pipe in the center like was suggested. This gives the sweep auger a pit to empty into and a pivot point. Next I would cut an opening in the side near the bottom of the barrel and cement the discharge auger in at a slight angle. Fill in with sand till you get the depth of cement you want, pour the cement and it will be a neat job that will last the rest of your life. Also don't forget to put a little door that you can control from the outside of the bin just inside the walk door down to the auger so that when the grain stops flowing you can unload the grain that is still piled next to the walk door. Hope some of these ideas help. Tom

Dave, We did the ground work for a bin a few years ago. No picture but tapered gravel in bin center. Drove a piece of rerod in center and painted a circle and then built gravel up and tamped in 4inch lifts. The concrete contractor said it was one of the nicest jobs he'd seen.

You are doing the right thing putting up a bin. I never met anyone who regretted putting one up. If you need 5000 capacity consider putting up two 3000 bushel instead. Really gives you some flexibility. Yes they cost more per bushel but you can get them for nothing, around hear in so. Mn. anyway. Drive around the neighborhood. Every other farm has one of those 3250 govt. bins sitting there not being used. Just pull in and tell them you will get it out of their way. Govt. put them up with a tin floor. One of the three I moved in still had the tin in it. That really makes for a cheap move. All you need is a load of sand. All my bins have the unload tube coming out at ground level and I just shove the flighting in and u-joint it to the 1 " stub on end of my truck auger. Works good except in winter with snow and ice build up. 9 times out of 10 I don't start hauling out until April so no big deal.

Dave, I have a set of three bin jacks that I have used to take down a few 3500 bu Gov. Bins. If it would help you, you are more than welcome to use them if you decide to move a used one yourself. I don't think I live that far from you. I am in Mason county. Good luck,,, Al

I hope you are not afraid of heights, an 18' bin that will hold 5000 bu. will give you a nose bleed climbing to the top! As stated, the taller the bin, the harder it will be to push air thru the grain when full, read bigger fan. Taller bin, longer auger. For 5000 bu., I would look at either a 21' or a 24' bin or 2 18' bins. Are there soybeans raised in your area? With 2 bins, if you decide to raise some beans then you will have a bin for corn and a bin for beans. Something to think about. Chris

With heavy test weight corn and filling an 18 foot bin well into the cone of the roof you can get close to 5000 bushel. That would be a 7 ring bin (narrow rib bin sheets). I know it shouldn't be filled into the roof, but if the corn is dried outside of the bin to 14% I have never had problems. Cold weather easily penetrates an 18 foot bin freezing the corn. I have taken corn out of the bin in late June and it is still very cold.

I have put four 18' bins up in the last 8 years or so. Doing the concrete yourself probably cuts the bill by 1/2. The concrete delivered from town for the one I did this summer was around $800. Somewhere around 8 yards. The foundation for an 18 foot bin generally is a floating monolithic slab. That means there really isn't a footing, but rather a rat barrier. The slab on top is 6" thick. Under the outside one foot circumference the concrete generally is another foot thick under the top 6" slab. The entire slab/rat barrier is poured at one time. The overall diameter of concrete for an eighteen foot bin generally is around 19 feet allowing for 4", 6", or even 8" extra outside of the first ring. In that outside foot circumference where the concrete is 1 1/2 feet thick generally 2 - 5/8" or 3/4" re-rods are "circled" and located about 2" off of the bottom of the trench. I put little stones under the re-rod to hold it up 2" in the concrete and drive 1/2" re-rod stakes to hold one rod 3" inches from the outside and one rod 3" from the inside. In the top 6" slab I use 1/2" re-rod every 2 feet. One set of re-rod go perpendicular to another set of re-rod - looks like a checker board when you are done. Again these re-rod are all wire tied together and held up in the concrete 1/2 way by placing small stones or broken up concrete chunks under the re-rod. I generally put another re-rod around the top outside edge also - generally one 1/2". I have been putting plastic under the floor concrete to eliminate moisture migration. This is very important when there isn't an air floor, even with a floor I have covered the fill before putting the reinforcement in and pouring the concrete. To hold the bin down to the concrete I have been drilling holes into the concrete and using wedgelock bolts after the bin is built and centered on the foundation. To set up the foundation I drive a 1 1/2" pipe into the ground with exactly 1' sticking out. Tie a heavy cord (mason line) on to it making sure it will rotate around the pipe. I tie another rod or similar marking device to the cord 18' 8" out from the center rod. Walk backwards, keeping the cord tight, while scratching the soil. You can use your screed board to do this rather than the string. Drive 2" by 6" stakes every 18" or so on the outside of this line. Buy some 12" house lap siding (somewhat like Masonite)and attach it to the inside of the 2" by 6" stakes with drywall screws using a drill. To level the 12" lap siding as you attach it, I put a screed board on the center pipe and extend it over the lap siding. A couple big nails into the screed board pointed down into the center pipe helps to hold it. Put a level on top of the screed board. If you are doing this by yourself you can use clamps to temporary hold the lap siding while you adjust it up and down and attach it. After it is all formed up I run a 1/2" cable around the outside of the form. Each end of the cable has connecting points so I can snug it up with a ratchet puller (come along/fence stretcher). There is a lot of pressure and the cable holds everything together well. Then I dig the 1' wide trench around the outside 6" deep. The last thing to do is fill the center with 6" of fill - something like waste lime or gravel fines. Dirt will work if you can get it to settle or pack in a timely fashion. At times I have even formed the inside to hold the center fill with a 6" wide piece of lap siding. When done I generally put 6" of gravel against the concrete leaving 6" exposed. There are a lot of variations when doing the forming with the lap siding. One bin the entire 1 1/2' concrete thickness was above ground with deeper fill inside and then backfilled outside. On farm storage offers greater marketing opportunities. Lastly I wouldn't build a bin without an air floor and at least a 3/4 to 1 hp fan. Good luck.

Appreciate the info! Some pretty clever stuff there. So...pardon my ignorance...the unloading is obviously done from the bottom so there is an auger in the slab?

I am going to talk to a dealer. I don't want to buy someones old bin and find that a new one was only a little more. If I go used, what I end up with will be what comes down the pike. I'm trying to learn as much as possible before I pull the trigger on one. Thanks for the help!

I have the wire and stretchers on hand. Sounds like a good idea.

Thanks Tom! I understand most of that, not all. But I save all this to a Word file and study it as I gather more info. It will all make sense in the end. By the time I am ready to start digging, I will have it down.

Truck still running like a top, it is indispensable around here!

Nice! Can't imagine needing a bin that large. Not sure my old tractors, old combine and a middle aged guy could handle the work load.

I have a line on a 3000 bushel. It's sure not free or even close, but looks nice. I would rather have a couple smaller bins. Just makes more sense for me and for just the reason you mentioned.

I would go with more capacity than you think needed now as if you expand some you still have room. Alos as has been said the shallower the grain the easier it will be to move air through it. If you decide to go with 2 bins have them the same size so sweep augers and such are interchangeable. Check out how much electric service you have as if you decide to go with a dryer it will add up fast for amperage requirements. If you have a place with 3 phase it would be better to put the bins there as the motors are cheaper and will be easier for the dryer you should choose. 8 inch load out augers for the bottom will also not be regretted. We changed ours to that. If you have somebody come in to load in the winter or other time they will start with detention time for longer loading times with the 6 inch. Most like to load in about an hour or less.
I would not get a bin again without an air floor in it. If you get the air floor do not get that chisel or hawk cut floor it sucks to sweep when finishing cleaning out. Get a preferated floor that is smooth. We have one from Golden Grain that is smooth and has been nice to clean. it is in an old butler bin. You can shop for floors different than the bin manufacturer. Get the walkin door not that little square crawl in door. You will regret it the older you get if you don't. I am looking for a walkin door for one of our bins.
And you are welcome to come look at our bins if it will help with your decision. I'm in Shiawassee county only about an hour from you and a mile and a half east of M-52

Thanks Al! That's about 3 hrs but not sure where else I would find jacks. I would gladly make the drive. I sent you an email. Mine is open here also.

I am afraid of heights, but I get used to them after a while. I had to hide that pretty good on the fire department. They made us do stuff that could make your hair turn white. I am looking at maybe doing two bins. There are a lot of reasons it makes sense for me.

Dave not if you have an air floor. All of my bins do. The air floor is bolted about 12-18 inches above the bottom of the first side sheet of the bin. The auger goes under the air floor and has a hopper up through the air floor. Look at the picture and you can see how they are done. The sweep auger can be of two types some of the more modern one stay in the bin until you have it emptied down to the cone. All of mine the sweep auger comes out and is installed after you have the grain down to the cone.

If you do not have a full air floor then the unloading auger can be in the base concrete. I do not like those type of bins you just about always have spoilage against the concrete. Even the ones with air troughs in the floor still have spoilage.

It sounds like you want to be able to dry corn in the bin. So you will want a full air floor. Whether you have a fan with heat or not you still want a full air floor.

Second picture shows an air floor part way installed. There are many types of floor supports. The one in the picture has straight runs. I have never seen those type in person. The older bins used concrete blocks stacks. The newer bins use a steel stamped floor brace that are set in alternating rows under the air floor ( 3rd pic).

More good info, thanks! I'll add it to my private archive so I have it to reference down the road. That's how I get all this stuff done. I ask a lot of questions and then print the replies into a manual of sorts. I do all my own masonry and have for years. Flat work, block, stone...I like working with the stuff. Thanks for taking the time to help me out...that goes for everybody!

(quoted from post at 19:36:43 12/04/16) I am going to talk to a dealer. I don't want to buy someones old bin and find that a new one was only a little more. If I go used, what I end up with will be what comes down the pike. I'm trying to learn as much as possible before I pull the trigger on one. Thanks for the help!

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Dave,

If contacting a dealer for a bin, look up Just Right.. I think he still advertises in the farm trader, but I'm not sure. He lives around the corner from me (I'm about a hour from your area in Michigan) and he's been known to buy and resell used bins also. He's been trying to buy the ones on my grandad's farm for the last few years.

If you can't find his info, email me (should be open) and I will get you his contact info.

Brad

I have no idea how many acres you have or can have. I also would go with multiple bins. You might want to put part of it to beans at some time as well and multiple would give you an option a single will not do. I would try for 3 bins instead of 2, plan on one for beans and 2 for corn if you can do an every other year rotation. But if you would decide to go with corn only you would have that option. Remember the bigger you go the heavier it has to be built and heavier means more cost. I would try to find the smaller used bins that are no longer being use by the big farmers, even if you would have to put up eventually 4 smaller bins you will be ahead as you will have options. I wish I had bins when I was farming but I only had cribs. I think you are one that would rather haul your own crop than have a semi come in to pick it up. And the smaller cheaper setups would work as good for that. I would try to find a seperate dryer and not depend on a bin dryer for each bin, only a fan per bin. And you said you do not like heights, it only gets worse as you get older, I know from first hand about that, I always had the height problems and any more at 73 8 foot high is too much for me. If you set then right you can make like a fire excape stairs that could work for several bins and be a lot safer than a ladder and if planed for ahead you could do that down the years. You might even find one in good shape from a building being torn down. And at say 500 bu per load you have a better chance at getting a higher average price than if you send it all at 5000 bu in at once.

I have been around long enough to remember when the drying bins came out and at that time a 12 foot sidewall was tall and they were having spoilage problems with themm to control that it was then said do not put more than 6 feet of graon in no mater how tall the bin is. Dry that down and move the grain to a different bin and d ry that not over 6 foot as a second and third and 4th batch, So that is why the seperate dryers became popular. They did not have the stirers then that the bins have now that I would think cost a lot to get and maintain. Just air only to maintain depth is not as important as drying without being able to move the grain in the bin while drying. I wanted the 350 bu size batch dryer as it would have handled the corn as fast as the old JD 45 combine could harvest it.

I appreciate the info and the offer! It may help to look at someones setup to get a better idea of how this works. Time is going to be an issue for me right now and I would guess your bins are full anyway. But as we get closer to Spring I might like to look at what you have. You are not far from me. I'll shoot you an email. Thanks again!

Hey Brad, if you read this go ahead and email me the guys info. Your email is closed but mine is open. People use it all the time. Thanks!

Dave, The farm is run by twin brothers and their dad. They do over 800 acres of corn and beans and milk about 80 cows. The farm they grew up on only had about 30 head of milk cows in the town of Franklin N.Y. They jumped over the hill and rented a farm in Otego about 20 years ago and have some good river bottom soil now. They have mostly IH tractors and I think a 1460 combine, nothing new.