I am on a job cleaning up a grain elevator and distribution piping that was downed by a windstorm. It looks like somebody dumped a plate of spaghetti on the floor, but only one of the grain bins was damaged. It is asmall bin, about 20' in dia. and 20' high. It is a regular bin, made of bolted together panels. About 4 roof panels are damaged, and then something like 2 panels in the top ring, and 1 in the 2nd and 3rd will have to be replaced. I'll try to remember to get some pics monday. I remembered the camera today, but, not the batteries. Okay, here's what I need help with: I think it should be practical to unbolt the damaged panels and bolt in new ones. I have a 25 ton truck crane, a manlift, and a forklift on site. The owner was told by the bin company that it is impossible, the whole bin has to come down and then be rebuilt from the bottom up like they do new ones. Have any of you ever tried this?
I agree with the bin company, from the extent of the damage i would take it down to ground level. Redo the roof then build it back putting new panels in where necessary.
I grew up doing grain bin work in Iowa. The sheets on the top ring can be the hardest to replace, but you can use your crane to hold up the roof sheets. We would build scaffold on the inside of the bin, and then use ladders on the outside, but you've got a manlift to do the outside. I've had almost 1/3 of the sidewall sheets removed from a 36' dia bin, replacing wind damaged sheets. I've also replaced whole roofs, on up to 48' diameter bins, 1 sheet at a time. If you've got some bars and some line up punches, it takes a little work but you can replace the sheets. The biggest problem can be getting new sheets to match the old one's. A lot of the old manufacturers are out of business, and most of the roof sheets are different. The sidewall sheets are fairly standard to bolt pattern, but there is some old oddball stuff out there. Make sure to use new bolts, or replace the neoprene washers, and put new rope sealant in between the sheets, otherwise it will leak. If the bin is old, oddball stuff, and you have to fit a new roof and some sidewall sheets, no bigger than that bin is, it may be quicker to tear it down. But it is possible to change them in place.
If you have a crane onsite, it can be done to replace the sheets, but talk to the owner and lay out a few simple things first, one does he want the bin the exact same size, second, how much does he want to spend on the bin, and lastly, how much time do you personally want to send on the bin, most owners want something bigger anyhow and to do the repair in place, no offense intended, but if you have no experience doing that kind of work, it might be faster to tear it down and put it back up again, for one thing, then the roof is at ground level, not 20 feet or more up in the air and depending on how old the bin is, like has already been stated, replacement parts might be a bit tough to get, if even possilbe to get at all. If it were me, I'd take it down and start over and put it back up again with new sheets and roof components in place, maybe even add some more layers to make it taller and hold more, if its possilbe to do with the existing leg operation your replacing. If components can't be gotten to do the repairs, I'd tear it down and try to sell it as is and install a new bin back in its place, or go bigger on some other spot in the existing operation. Now that said, I'm sure there's a drying floor in the bin already, if so, I"ve seen it done with scaffolding inside the bin to go up to the last good layer and unbolt the whole bin and use the crane to set the rest aside and tear it down and rebuild it and then set it back on the remainder of the good base sheets level IF there is even room to do that in the grain setup. Take some pictures of not only the bin but also the whole setup, so we can see just what your looking at and how the bin sits in the setup. The roof is the hardest part to replace and I want that as close to the ground as I can get it to do the repairs, but I don't like ladders and scaffolding much and depending on the extent of the damage will determine how much I'd tear it down to work on as well, along with how the bin sits in the grain setup. For a smaller bin, it takes about an hour per ring height to remove and put back up and its way faster to do the replacement sheets on the ground and eliminate the scaffolding completley, not to mention fighting the roof sheets to repair, with the time involved I'd take it down and put it back up again for a bin that size and never give it a moments thought, now if the bin were bigger say 36 foot plus, that might be more feasable to try to replace things in place, but not for one that size, escpcailly if you have a crane onsite. That also gives a chance to reseal the bin install new bolts and washers. Just my two cents