How to Level a Sloped Platform

Here’s the basic instructions from our video on Alan Thrall’s YouTube channel. We decided on this method because it’s inexpensive, requires only a few simple tools, and doesn’t need master craftsmanship to construct. Anyone can easily adjust this design to their specific needs whether it’s for a professional facility or a home gym.



Weightlifting/Powerlifting Platform (8×8 ft)

Supplies

  • 2 (3/4-inch) particle board 8x4ft
  • Sheets of approximately ¼-inch plywood (actual number will depend on the slope of floor)
  • Liquid nails, likely between 4-6 large tubes
  • Wood screws — you’ll need some of different lengths depending on the number of layers of plywood under the particle board
  • Depending on what type of platform being built there will be another layer. Possible options include:
  1. One 8x4ft piece of hardwood (e.g., oak or redwood) and some rubber
  2. For heavy duty workout platform another layer of 8x4ft (X in) particle board can be added perpendicular to the other pieces of particle board
  3. For a competition platform, a thin layer of carpet or rubber are good options on top

Tools

  • Circular saw
  • Power drill
  • Tape measure
  • Level
  • Utility knife (optional if using carpet or rubber)

Steps

  1. Determine the slope of the floor to determine how many layers of plywood will be needed to level the platform.  Take one of the particle boards (or another 8 ft long board) and lay it along the floor where the platform will be placed.  Put the level on the board and lift the end of the board at the low end of the floor until the board is level. Measure from the bottom of that board to the floor.  The example in the video was 1.5 inches.
  2. Divide the needed measure from step 1 by ¼ to determine how many sheets of plywood will be needed at the low end of the floor. In our example it is 1.5 inches divided by ¼ inch leading to 6.
  3. Figure out the lengths of the ¼ inch pieces of plywood by dividing 96 inches (the length of the 8 foot board) by the number of sheets needed.  Note that you will use the number found in step 2, then add 1 to that number since the first section of the particle board on the high end of the floor will be directly on the floor.  So in our example we’ll divide by 7, and each board will be 13.7 inches shorter than the one before it. Note that these boards do not have to be exact and many times you will find that the shortest one and the longest one can be made from the same piece of plywood.  Then the second shortest and second longest can be made from the second piece of plywood. You will be making two layers of 8x4ft plywood stacks for the entire 8x8ft platform. 
  4. Cut the boards into the lengths needed:
    1. 13.7
    2. 27.4
    3. 41.1
    4. 54.8
    5. 68.5
    6. 82.2
  5. Glue the plywood together using liquid nails creating two wedges of plywood to go under the particle board. To make sure the liquid nails had completely dried before adding the next layer of the platform, we set weights on top of the wedges and let them sit overnight.
  6. Attach the particle board to the wedges using wood screws. Start with the perimeter of the platform. We recommend setting some screws along the seams of the wedges to help prevent them from separating.
  7. Optional: attach another layer on top of the particle board depending on what the platform is being used for (see supplies above for ideas). Most of our platforms are topped with oak hardwood in the center with rubber along the sides. This makes for a professional looking platform, but high-end hardwood and rubber aren’t cheap. Also keep in mind that every additional layer makes the platform substantially heavier thus harder to move.
  8. Start lifting!

Got a question about the design? Anything you’d do differently? Let us know in the comments below!

22 thoughts on “How to Level a Sloped Platform”

  1. Excellent article and video. I understand you have used this method many times with great success (insert Borat thumbs up). Have you ever had to make one where the slope is going in more than one direction? For example, a garage floor that has a drain in the center will have a slope constantly changing depending on where you are trying to put the platform relative to the drain. This in turn would give you different measurements during step 1 depending on which corner of the platform you would be measuring.

    1. Fortunately I only have to account for a slope in one direction. But yes, you’d have to taper the shims to one corner rather than just an entire side by running through step 1 twice.

  2. In your example did the 7 boards take care of the whole 8×8 platform or should I get 14 total boards? I have about the same slope.

    1. 7 would get the job done. The number of boards for the shim will depend on slope and the thickness of those individual sheets. if have a similar slope to us and can procure ~5mm boards, 7-8 sheets will get the job done.

  3. Hey I might be late to the party on this one, so my slope is not that severe: it’s right around 3/4 in. Therefore I would need about 3 pieces of 1/4 in. My question is is it ok for most of the top layer (3/4 in 4×8) to be off the sloped platform? Meaning, here will be 2 ft hanging off the sloped app platform underneath and will that be ok to lift on? Also, if I am screwing the two top pieces of 4×8 then exactly 1/2 my platform will be on a higher level then the other half. How do I ensure that the two top 4×8’s flush evenly so there’s not a piece sticking up? Also would it be wise to always place the top pieces perpendicular? Sorry for all the questions and thanks for making that great tutorial!

    1. Hey Gabriel, ideally the non-shimmed end of the top layer will be flush with the floor. I recommend finding thinner plywood to correct the smaller slope — you can normally find 1/8-inch plywood at big hardware stores. Go thinner if you can. That should level your platform and close the gap at the non-shimmed end.

      If you’re only using one layer of plywood plus the shim, you’ll want those 4’x8′ boards to be perpendicular to the shims. Otherwise you end up with a two-piece platform with nothing to keep those pieces connected. I think this can also be corrected by using the thinner plywood for the shims.

  4. So I’m making a platform that’s 4′ deep and 8′ wide due space in my garage to park my truck. Should I divide into 48″ instead of 96″?

  5. Hi there, not sure if this matters, but when you create the wedge, are you going from smallest to largest (with the smallest wedge being the one directly on the ground and the largest wedge is touching the bottom of the platform), or vice versa?

    Thanks!

    1. Hi Rich,
      I’ve tried both variants, and it seems to work best with the longest piece of the wedge in contact with the ground. You could definitely do it the other if that’s what you prefer!

  6. Thankyou for the guide, I have a 2cm slope in my garage that I will be using your method to fix, do you think it matters which side of the wedge you screw to the top? In the video you screw the top with the largest wedge on the ground I was thinking of doing the opposite so the largest wedge is against the top mainly because my garage floor is not smooth concrete and I figure the different levels of ply will tolerate the small bumps and textured finish better

    1. Hi JC,
      If you’re working with a surface like the one you’ve described, it might work better screw the longest part of the wedge directly to the top of the platform. That should help account for the textured concrete while still having a level platform.

  7. Thank you! Will begin this project shortly.
    Yours seems to be the most promising one given what I’m trying to do in my garage.

  8. Thanks for the tutorial. I have a slope of about 1/2 inch left to right.The smallest plywood I can find is 5mm. Do you think this will work? Any advice would be appreciated. Thanks again.

    1. Hi Adam, 5mm should be small enough to use this approach to leveling a platform. Since you have a limited slope to account for, you won’t need as many layers as shown in the demo.

  9. Excellent video! I am planning on building an 8×8 platform, but I have around a 1/2 inch slope. The smallest plywood I can find is 5mm. Do you think this will work? About how many 5mm sheets do you think will be needed? Thanks in advance.

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