Oil tank roof structure

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I am going to be building a steel roof structure over a 14'x37'sq 8' high diesel holding tank. I was wondering if anyone has ever done this before and could give me any details how they did it... or how i should. It doesnt need to be very heavy material roofing, but its still quite a big roof. I am no architect by any means and we are not looking to hire one either..(unfortunatly),also the tank is sitting on a concrete pad. any help would be apreciated. -Thanks"My fingernails are melting"
Reply:if you are going for permits then there are deffinate structural plans to folow and most probably they want an architect to make drawings, if no permits are you using the tank as part of the supporting structure, like welding brackets onto the tank? ( probably not a good idea as the tank was not designed or those loads..albany gets lottsa snow..
Reply:yeah, I will be running a 4 corner support system, with beams fastened op the concrete... There will be no permit issued. just looking for truss suggestions, pictures of something like thi, or to make it pitched or flat...  etc"My fingernails are melting"
Reply:A 14' span is relatively minor, if you can run the joists that way. You could cut that to about 8' IF you can run a ridge beam the 37' length.A "shed" roof with a 14' span on 16" centers is doable with 2x12" lumber on 16" centers and the beam supports on each side would be simple in wood, You just break the 37' span down into say <10' chunks.I'm sure it's easily doable with channel or small I beams, exact sizes would need to be determined by expected load, pitch, span etc.I bar joists would be another option. I have a text that lists loads and lengths to spans of up to 60'. I would just check with the suplier to see what they would suggest and then size the support beams acordingly.You need a lot more info to get any sort of idea. Will it be a "shed" type roof or a "gable" with a ridge beam? Can you just span the 14' dist or do you need to span the 37' length? If you do a "gable" can you break it the long way into 2 19' spans with a ridge spaning the 14' or does the ridge have to run the full 37'? Can you do intermediate posts on the exterior or does it still need to span the full 37' on the out side?Edit: In NY I would definately have a pitched roof of some sort. A true flat roof will require signifigantly more support to handle snow loads compared to a pitched roof. The more pitch you can get, the lower the snow load will be, but it complicated the design construction a bit.Last edited by DSW; 07-06-2009 at 04:38 PM.
Reply:I can span the 14', what exactly do you mean by running a ridge beam to cut it to 8'?? also, i can have as many supports as i need on the exterior between the 4 corners. this is something that encon is making us do."My fingernails are melting"
Reply:Originally Posted by copperpotI can span the 14', what exactly do you mean by running a ridge beam to cut it to 8'?? also, i can have as many supports as i need on the exterior between the 4 corners. this is something that encon is making us do.
Reply:I am confident I can do it, I will need to build this out of metal (fireproof) I understand that I may not be a carpenter but i can build it if i see it.Im just trying to get a mental image before i put it on paper."My fingernails are melting"
Reply:A very simple sketch, maybe this makes sense.The sketch shows a basic shed spaning the 14' width, and gables spaning both directions. the real crappy 3d views shows both the shed spaning 14' and the gable spaning 14' with the 37' ridge marked. I would not try to make the ridge run 37' if I could find a better way, but as said there isn't enough info to make any solid suggestions.In lumber this isn't that hard. There are tables that list loads for spans for the beams and the roof joists. BUT you still need to understand the basics to put it together. In steel I'm sure it's doable, but I don't have enough info on steel spans and costs to make educated guesses.EDIT: Wood structures often have better fire ratings than steel structures. Steel to be "fireproof" needs to be coated. Wood because of it's insulating nature is frequently used in "fire rated" construction.Last edited by DSW; 07-06-2009 at 06:06 PM.
Reply:Originally Posted by copperpotI am confident I can do it, I will need to build this out of metal (fireproof) I understand that I may not be a carpenter but i can build it if i see it.Im just trying to get a mental image before i put it on paper.
Reply:Originally Posted by 7A749Always nice to have your input DSW. Listen to this guy, he knows what he's talking about!
Reply:Remember Albany NY gets alot of snow.  Up in our area 3foot snot capacity is typical for construction.  I'm sure your oil company will be even less happy if the roof you put up crushes the tank and causes a leak than if you don't put it up."...More average snow may weigh 15 pounds per cubic foot..." (click to see reference)Using this estimate, your roof would have to hold 14'x37'x15lb/ft = 7770lb per foot of snow.  At three feet deep you are talking 11.6 Tons of snow!!  If that makes you a little nervous (it should) then maybe you'll be convinced to seek some professional help.  I'm an engineer by training, but don't do structural stuff for a living, and wouldn't venture to design this structure.At the very least, make sure the roof has a steep pitch so it can't collect much snow.YMMV.  Caveat Emptor. Etc. Etc.
Reply:Maybe I'm wrong here, but, being "fireproof" is pointless. Any structure built over 30,000 gal of diesel will burn, melt, or crumble, no matter what you make it from.Last edited by fortyonethirty; 07-06-2009 at 08:17 PM.
Reply:Originally Posted by nes_mattUsing this estimate, your roof would have to hold 14'x37'x15lb/ft = 7770lb per foot of snow.  At three feet deep you are talking 11.6 Tons of snow!!  If that makes you a little nervous (it should) then maybe you'll be convinced to seek some professional help.  I'm an engineer by training, but don't do structural stuff for a living, and wouldn't venture to design this structure..
Reply:[quote]A single joist on 16" centers spaning 14' would carry... 1.33' (16" centers) X 14' (total span length ) X 3' (depth of snow) X 15lbs (weight of snow given) =840lbs that you would split between the 2 supporting beams, so 420lbs per 16" of beam. Thats assuming a flat "floor" and not a sloped surface.[quote]Correct, this good way to look at it.  This is the fraction of load each joist needs to carry.  Using the 840lb/1.33ft gives the same total load result I stated.
Reply:Originally Posted by DSWEDIT: Wood structures often have better fire ratings than steel structures. Steel to be "fireproof" needs to be coated. Wood because of it's insulating nature is frequently used in "fire rated" construction.
Reply:Hard to collapse an arch with an evenly distributed load.Last edited by joethemechanic; 07-06-2009 at 10:08 PM.Joewww.CummingsHauling.com
Reply:thanks for all the input guys i will take all this into consideration when i start to build. I will post some drawings up soon and tell me what you guys think..  Thanks ALOT!!"My fingernails are melting"
Reply:You should really probably be following plans drawn by an architech.  Some thing that is thought through and easily followed.  Just my .02 though.
Reply:you know guys there are more than one book out there with pre drawn blue prints it may be as easy as looking for it online or even going and ordering it from your local book store. My father has a book of award wining desings for houses has over 200 desings.Last edited by Teljkon; 07-07-2009 at 07:12 PM.
Reply:I am able to do research and i should be able to use formulas as stated to decipher the proper load vs.said structuring, I will be making my own drawings this week then i will figure out pricing on the material i am going to need. Ill keep you guys posted on this quest I was put on.  Also, my boss told me today that he just wants a cheezy roof put over it nothing special!.... to this i simply replied "There is not a cheezy way of doing it, If its not done right then it will fail especially under heavy snow load" To that he replied.... Well do it however you gotta.  So you see the pickle im in. I have to do it, because i was instructed to. H wants me to run support off the tank structure itself... which i wont do. Once again, THANK YOU  for all the help. I love this forum!!!"My fingernails are melting"
Reply:Originally Posted by DSWActually you're equation is calculating the entire roof load not the sq ft load.A single joist on 16" centers spaning 14' would carry... 1.33' (16" centers) X 14' (total span length ) X 3' (depth of snow) X 15lbs (weight of snow given) =840lbs that you would split between the 2 supporting beams, so 420lbs per 16" of beam. Thats assuming a flat "floor" and not a sloped surface.Still your point is well made. The roof needs to be designed to take that weight plus the weight of the structure itself. Local codes call out the required loads for roofs XX lbs/sqft snow load + XX lbs per sq ft dead load (structure weight). As said its best to get this designed if posible. Some suppliers will help with in house calcs if you supply basic data.