Basically I've constructed a raised shed foundation using piers concreted into the ground, however they are out of square by 2 inches in opposite corners, so the shape is a slight rhombus. See below circled in red, the same has happened in the opposite corner.

joist overhang

The parallel piece on top is square, so I could either continue building on top of this and leave the overhanging piece visible (how could I hide/cover it?) or potentially add sistered joints on the shorter joists to bring the structure square (best way to do this?).

Repositioning the piers at this point isn't really going to be possible.

Please suggest anything else I haven't considered.


  • What's the actual problem, as you see it? As long as your beams have full bearing, the only issue is aesthetic.
    – isherwood
    Sep 30, 2019 at 15:59
  • By the way, you might post your floor framing plans for evaluation (in a new question). As it is it seems that you're using a single 2x4 as a beam in the most load-intensive portion of your floor. You'll want to isolate the lumber from the concrete, too. (I always frame shed floors with treated lumber.)
    – isherwood
    Sep 30, 2019 at 16:00

2 Answers 2


It rather depends on your shed construction, but can't you just have the wall overhang the beam by 2" (or even 3")? That way the overhang will cover the error up completely.

  • Thanks for the suggestion! I can’t quite imagine the best way to achieve this, would I need additional timber on the side of the wall to push the final layer of timber out?
    – George
    Sep 30, 2019 at 18:38
  • @George That's one way - or just have the joists projecting out beyond the posts a few inches. Oct 1, 2019 at 7:07

The easiest way to get a square floor is to replace the joists that are currently running left to right in the picture. Cut them longer so they cantilever a few inches at both "short" corners of the rhombus. If the size of the shed is constrained by lumber dimensions like plywood sheet size, you can cover the little ends of the joists with extra siding or aluminum flashing.

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