Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums

  • If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement Module
No announcement yet.

Steel tube in/on concrete for fabricated roof on block shed, corrosion?

Page Title Module
Move Remove Collapse
Conversation Detail Module
  • Filter
  • Time
  • Show
Clear All
new posts

  • Steel tube in/on concrete for fabricated roof on block shed, corrosion?

    I'm building a 12x24 concrete block shed. I would like to build my own 6:12 pitch trusses from 2x3x14ga steel. I know this sounds like a lot of work vs wood but I want something simple that will last forever with no maintenance, so that means no exposed wood eves, i can keep these trusses completely sealed up inside the building and deck over with metal roofing. There is lots of moisture in florida that rots wood over time. The trusses will get concreted into the top lentil blocks of the walls when the cells are filled, and i will weld the trusses to the vertical rebar. Is there any potential for detrimental corrosion over time due to concrete's alkalinity. I know rebar holds up because it forms an oxide layer and is sealed inside the concrete, but this will only be partially sealed since it is at the top.

  • #2
    In Australia you would have to have council approval to do this kind of work. The council would require an engineer to design & certify said structure. Here we would cast a hot dipped galz threaded rod into the lintel blocks if the structure was more than 1 kilometre from the sea and a stainless steel threaded hook rod if closer than 1 kilometre.



    • #3
      Steel tube in/on concrete for fabricated roof on block shed, corrosion?

      I don think I would surround the truss with concrete. Even if it were galvanized. If I were doing a block wall with metal truss I would;
      A: make sure the top of the two load bearing walls were poured solid and rebar plus at least a 4" cap block as the last course.
      B:have two pieces of angle sandwiching the trusses together held in with tapcons. Two per angle.
      C: crib the shart outta it and metal roof.
      D: have at least a 16" overhang and make some cool soffit for it(keeps the critters out).

      Just my $.2! Hope it turns out well for ya whatever you decide to do. Keep us posted though.


      • #4
        Steel tube in/on concrete for fabricated roof on block shed, corrosion?

        Don't surround the metal with concrete. Just use some pieces of angle and tapcon them ontop of the last course of cap block. Walls should be filled with rebar and concrete on
        the load bearing walls at least if not all of them. Make sure you use vented soffit so to keep critters out and let the roof vent. Just my $.2.


        • #5
          The block wall buildings I worked in have 1/2'' thick, 6'' X 8'' , plates for the trusses. The plates have a rebar ''J'' hook about 18 '' long welded to the plate. The plates are set at truss centers and rest on top of wall with the ''J'' hook mortared in.


          Special Offers: See the latest Miller deals and promotions.