Can I use pre cast concrete blocks footings, to build..??

Discussion in 'The Garage' started by Ricardo Kuhn, Oct 27, 2013.

  1. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    A wood platform for a 15' x 8' plastic shed or do I need to cast them my self for stronger results..

    Something like this, I'm guessing I will need six of them, but maybe I'm also wrong..
    [​IMG]
    #1
  2. ktm360mx

    ktm360mx Stone Cold Puppy Pa

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    That's very similar to what our shed rests on. We have a 10X20 shed with a side door. Blocks like that about every 3-4 feet. It's been on them for the past 10 years or so.

    We received A LOT of rain this spring and the blocks sank into the ground an inch or two in various places. Now the floor is a bit wavy, but the entrance door is still square.

    You may consider digging down a 6 inches below each footing and placing gravel or road base, then the block on top of that.

    Good luck- it's worked well for us for a long time.
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  3. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Yes also get a ton of rain and snow around here, so that was my biggest concern..

    Yeah I was thinking of installing flat concrete stone squares under the pyramids to increase the load capabilities but the stone is also a great idea..
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  4. Cogswell

    Cogswell Spudly Adventurer

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    I would opt to go with something that has a larger "foorprint". Maybe a 4" thick solid cap block. How much weight are you planning to put in the shed ?

    Mike
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  5. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Yes that is the idea...
    1200 pounds at the most on really hard dirt..
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  6. Cogswell

    Cogswell Spudly Adventurer

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    Use as many support points as you can, or just do a full perimeter support to help spread out the load. You could make a rectangle out of the cap blocks and lay a 4x4 or 6x6 lengthwise below the front, rear, and side walls.


    Mike
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  7. Dustodust

    Dustodust Long timer

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    overkill for a plastic shed :
    [​IMG]

    underkill for a high rise :

    [​IMG]

    if its not in threat of standing water I would think 2" of sand and 6mil plastic sheeting would be more than sufficient
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  8. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    I was thinking 6 blocks holding 4x4 vertically and beams every 16" on center, just to make things easier..

    Sorry Mike I did not get that Lengthwise you mean another "ring" on the inside of the main structure to help hold the plywood in place or what...??
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  9. Cogswell

    Cogswell Spudly Adventurer

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    Yes this would work, what size beams ?


    You could do it directly below the perimeter framing and one down the center. Again depends on the dimension of lumber being used.

    Mike
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  10. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    I was 2x8 for the perimeter and 2x6 for the internal beams, cover on 3/8 OSB, but then again I'm here to learn and follow sound advice..
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  11. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Very clear concept, I hope nobody die when that building collapse
    Since I'm doing all the work my self and by my self, I think a little overkill is necessary just in case I miscalculate something.. :deal
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  12. troidus

    troidus Long timer

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    Home Depot has a worksheet for calculating deck materials for supporting a shed. If I used it correctly, they said to use 36 pier blocks for a 10x12 footprint. That seems excessive, but I bet it wouldn't sink.
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  13. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Oh man 36 is a little much don't you think..

    I go and check the store tomorrow to get a better idea of what I need..
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  14. walkingbear

    walkingbear Long timer

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    how are you going to deal with the water under the shed?
    Myself, I would build a drainage system to get the water away
    from the piers.
    #14
  15. slackmeyer

    slackmeyer Don't mean sheeit. .

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    Do you have a truck you can use to get some gravel or crushed rock? Actually you could just load up some cheap rubbermaid tubs or buckets in a car. anyway, what I would do:

    clear your spot down to flat bare ground, try not to overdig- you ideally want to go onto undisturbed soil.

    Spread out a few inches of gravel

    Build your shed on skids: 6x6 or 6x8 or 8x8 pressure treated fir. You'll want them running the 15' direction. If you bevel the bottoms of the ends, it would make your shed easier to relocate later by pulling it with tractor or truck or come along.

    Then run your 2x6 in the 8' direction, with 2x6 rimjoists sitting on the outside of the skids, then ply that over with a 3/4 ply (osb is ok for the sidewalls, but either use cdx ply or something like advantech osb for the floor, where water might sit).

    Around here, if I made something like that I would use pressure treated 2x6 for the floor framing. SLC is probably a cold/dry climate where you could get quite a long life out of standard framing lumber, especially with the gravel to keep things drained.

    I think the big pressure treated timbers might cost a little more than the precast blocks, but it eliminates having to use any of the posts and beams, and the building will go much, much faster.
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  16. Laconic

    Laconic Anodyne

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    36 of those blocks? It should be a lot of fun getting all of those level with each other.
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  17. troidus

    troidus Long timer

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    Oh, if I follow through on moving my shed I'm using only 20 blocks, not 36. I think 36 is a stupid number.

    Fortunately the blocks don't have to be level with each other. That's where the 4x4 posts come in. And I figure on leveling the platform on the four corners, then put the rest of the uprights in. Then I'll set the shed on top of the platform. (I'm trying to figure out a way to move and lift the shed without spending $300 on a roadable forklift.)
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  18. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    That sounds very simple to do, except I forgot to mention the patio is on a incline (about 1 1/2' drop in 8') so it needs to be mounted solid since every inch is different and the whole thing can slide downwards if I'm not careful..
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  19. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Yeah I know may as well make it 72 and cover the little gaps in concrete..:huh
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  20. troidus

    troidus Long timer

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    You may be better served by getting out the posthole digger and casting wire-reinforced cylindrical piers. You'll have to get past the frost line once you start digging, though.
    #20