40×48 pole building

  • 40×48 pole building

    Posted by BiggKidd on December 5, 2022 at 1:30 am

    I’m considering building a pole building of several levels and I need some help. I will be using lumber cut on site and the roof pitch will be somewhere around 7:12. I’m trying to figure out what size floor trusses I need to make to span 40 feet and have serious weight carrying capacity. Tag you mentioned in the live stream the other day that framing was your area of expertise. I will also need to take a staircase or staircases through the floor(s).
    The plan here is to start off with a basic shell and building the top floor first because the living quarters will be up there or partially up there. While leaving the bottom open for now. Think of it as a 1000-1200 sqft bonus room which will be a living area with a nearly 2000 sqft work space under it. I want to see how the first part goes getting the basic pole building framed and roofed. That way I can work under cover. Once I have covered space I may or may not decide to dig a full basement under it. Then put a first floor level in with the work space now regulated to the basement area. Which will be possible due to the open design.

    I have the roofing material (metal) in hand along with some hardware IE: nuts bolts screws nails.

    BiggKidd replied 2 years ago 4 Members · 8 Replies
  • 8 Replies
  • Hippocrates_Garden

    Member
    December 5, 2022 at 1:42 am

    Interested in the replies from knowledgeable folk. BiggKidd, are you expecting the trusses to carry anything other than the weight of the roofing materials, insulation, possible snow (what is your area’s snow load), perhaps a bit of wire and piping, or will it be structural for the living space?

    I’m kinda considering something similar, but of course different dimensions due to my property, likey a fairly custom build as it will likely be somewhat triangular, with a single sloping roof @ about 30 degrees for solar water and power panels etc.

    I did find this, for those like me that are like, “what do you mean there are different kinds of trusses?”

    Roof truss design – Myrooff.com

  • BiggKidd

    Member
    December 5, 2022 at 2:20 am

    Sorry I forgot to specify floor trusses in the first post, I went back and did. The rafters will likely be 2x material. But I want to floors stiff as concrete! I also want them to be able to carry HEAVY LOADS!

  • TagNBee

    Community Leader
    December 5, 2022 at 3:38 am

    40 foot is a big span exspecially because you want it to hold real weight. I am assuming that you want them clear spanning. You will probably be forced to use a floor truss. If your willing to put a wall down the center of the bottom floor you could use TGI beams or something simular. I have a very good friend who designs trusses for a living. If you would like to visit with him , let me know. Tag

  • TagNBee

    Community Leader
    December 5, 2022 at 3:40 am

    Hey, one more thing. I would stay away from a 7/12 pitch roof. I would use a 6 /12 . Reason is the 6/12 is a common pitch and most things are availible for it ( stove pipe flashing, for example)

  • BiggKidd

    Member
    December 5, 2022 at 4:01 am

    Thanks Tag I might get you to put me together with him later but a whole lot needs to happen first. The roof pitch is going to fall where it falls working with material on hand but 7:12 is close could end up 6 or 8 and the standard pipe adapters and such generally work fine since they have rubber lips. When I do this I will be building every piece I can onsite since I have a MAJOR lack of funds. The only way I will get away with this is since we live in an area that allows agricultural pole buildings to be built without permits or inspections and what they don’t know won’t hurt them. lmao! As slow as this project will happen I highly doubt anyone will even notice when it slowly changes from a barn type pole building in to an enclosed space. Since I will be working alone for the majority it will take 3 to 5 years I would guess!

    BTW I live a good ways from anyone else and on a private road so not to many people will even know it’s here. Very few people even know we live here now and have for 15 years.

    • This reply was modified 2 years ago by  BiggKidd.
  • BiggKidd

    Member
    December 11, 2022 at 5:35 pm

    So I’ve been spending a lot of time thinking on the pole building design. Now that I know I can span the entire 40 feet I’m wondering if I should or not? One big problem for me is the lack of substantial footings. If the building 40×48 is just sitting on 10 posts that would mean the weight is going to be sitting on about 10 sqft and that just doesn’t feel like enough. What do you guys think? I have a 12 inch auger to drill the post holes with. I could possibly open the holes a little larger and maybe get 16 inches at the bottom. I am planning to set the posts on a poured concrete plug to spread the load a little larger than the bottom of the posts. This building is probably going to end up carrying some weight!

    Does anyone know where I can get some poster board size 1/4 inch ruled graph paper for drawing plans?

    • Private_Cluck

      Member
      December 11, 2022 at 7:10 pm

      Conservative loading bearing capacity for soil is about 2,000 lbs per sq ft (Source: Table 401.4.1; CABO One- and Two- Family Dwelling Code; 1995). So, if you have about 10 sq ft of load area, then you could support about 20,000 lbs.

      • BiggKidd

        Member
        December 11, 2022 at 7:33 pm

        Yeah and I’m afraid that just isn’t going to be enough. I think I’ll increase the size of the pads the posts sit on. The end walls posts will also carry a small part of the load but I want to be absolutly sure I have a good solid foundation.

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