Powerlifting Platform

This page describes the process my partner and I followed to construct a platform for powerlifting and Olympic-style weightlifting in my garage. I like planning things out as much as possible, and online articles I found didn’t have sufficient detail, so I had to wing it on some things. Hopefully the below description gives other builders a bit more detail or inspiration to help them plan their own platform build, but I am not advising you to follow this procedure, and I accept no liability from injury or damage resulting from its application. This article is for documentation only.

We performed some steps out of order in our build, so you may see some steps completed in the pictures before they are covered in the text.

Platform Supplies (more details at end):

• (1) 4’x6’x0.75” horse-stall mat
• (4) Plywood 4’x8’
• (1) Hardwood plywood – 4’x8’
• (1) Hardwood plywood – 2’x4’ (cut in half to make two 2’x2’ pieces)
• (10) Simpson Strong Tie Titen HD concrete anchors 3/8” shank, 5” length
• (3+) Tapcon 1/4” concrete anchors
• (~130) Screws
• (36) Washers
• (4) Heavy Duty Liquid Nails tubes
• Stain 1 qt.

Tools (more details at end):

• Drill with drill stop
• Drill bits
• Hammer drill
• Masonry drill bit – 3/16” shank x 5-7/8” length
• Masonry drill bit – 3/8” shank x 12” length
• Chalk line
• Combination square
• Large framing square
• Calk gun
• Paint brushes
• Razor blades
• Caliper (dial or digital)
• Tape measure
• Black Sharpie
• White paint pen or silver Sharpie or gold Sharpie (something to mark on black rubber)
• Misc other things like gloves, safety glasses, wrenches, vice grips, pencil, painter’s tape, etc.

Procedure

Research and Prep

I spent a while reading about other platform builds and looking at pictures to get design ideas and plan mine out. I took some measurements and evaluated the space in garage to determine the best location and orientation of equipment. I measured the downgrade in my garage (most garages are not level) to see if shimming would be necessary. I elected not to shim since mine was only 2%.

I created what I call a “hole map” on a platform diagram that shows where seams and fasteners exist in the platform stack. This is necessary to ensure that a screw or anchor does not land on a seam or another fastener. It also allows screws to be placed more quickly and with fewer spacing errors during the build.

• My hole map was made in Excel and consists of a 1’x1’ grid. I printed this out and sketched on the fastener placement. I adjusted the layout several times, which was much easier with a pencil than with a drill. The template is included at the bottom of this guide.
• The bottom two pieces of plywood are laid on the ground longitudinally (long edges are up/down on sheet). The bottom seam is in the middle of the hole map, labeled as “BOT SEAM”.
• The middle two pieces are laid transverse (long edges are left/right on sheet), perpendicular to the bottom two. The middle seam is shown with a bold line across the middle of the hole map left/right.
• The top large hardwood piece is laid longitudinally (perpendicular to the middle pieces), centered in the transverse direction. Each longitudinal edge is noted on the hole map, labeled as “TOP SEAM”.
• The small hardwood pieces are put in the upper (relative to sheet) corners.
• The rubber stall mat is cut (roughly) in half, and each half is laid alongside the center hardwood piece in the remaining top-layer space. These pieces are shown in black on the hole map.
• On my hole map, I used this key:
  • “X” indicates a screw fastening the middle layer to the bottom layer.
  • “O” indicates a screw fastening the top layer to the middle layer.
  • “Δ” (triangle) indicates a large concrete anchor passing through the rack mounting flange, the full platform thickness, and into the floor.
  • “*” (asterisk) indicates a small concrete anchor passing through the bottom two platform layers and into the floor.
• Each screw is at least 1” away from the next screw or seam. If two screws are shown directly next to each other on the map, they are 1” apart on the platform. If there is a seam shown between two fasteners, each fastener is 1” away from the seam and thus 2” away from each other.
• The large concrete anchors (“Δ”) are not precisely located on this map. I only placed them roughly then locked them down after physically mocking up the rack in the garage. See below.
• A hole-map template and my filled-out example are at the bottom of this page for reference.

After finishing initial research and planning, we purchased equipment, tools, and mat’ls. We had Lowe’s cut the 2’x4’ hardwood-veneer plywood to create two 2’x2’ pieces.

We then finalized the platform and rack positioning, following these steps:

1. Mock up bottom two pieces of plywood in position on floor to evaluate location.
2. Assemble rack loosely.
3. Position rack on platform for mock-up.
4. Install any peripherals on rack, incl. plate storage
5. Check clearance around rack:
   • Consider room for spotter behind bench if benching inside rack.
   • Account for ~1.5” (two plywood sheets) of extra rack ht that will be added when platform fully assembled under rack.
   • Consider where bar and plates end up at top of overhead press (inside and/or outside rack).
   • Consider sight line for each lift. I didn’t want to wall too close to my face when squatting inside the rack, for instance.
   • Make sure there is enough space outside rack for deadlifting, olympic lifts, etc.
   • Check everything with garage door both up and down.

6. Mark corners of platform on garage floor with painter’s tape when location is decided.
7. Measure on platform where rack will sit. Take note of final rack positioning. Mark rack-anchor measurements on hole map and ensure no interference with seams or other fasteners. I only aligned and measured one rack upright, using the nominal rack width to define the upright-to-upright hole spacing. The rack is only loosely assembled now, so that spacing won’t be right, and the rack is flexible enough to conform to this nominal spacing. Note on my hole map that only the left side has measurements.
8. Note also on my hole map that I have more dimensions than necessary to constrain the rack anchors. Several of these are calculated values from the nominal spacing and are for reference only.
9. Remove equipment off bottom plywood layer when this step is complete.

Platform Assembly

Then we started platform assembly and followed the below steps:

1. Evaluate which plywood pieces work best for bottom layer, in what arrangement and orientation. We tried a few different combinations before arriving at the final layout. The reason for this is that the garage surface is not uniform, and the plywood is not flat either, so certain pieces of plywood conform to the parts of the garage floor and each other better than others (targeting no gaps).
2. Repeat above process for middle two boards (decide orientations).
3. Double check positioning and seams:
   • Make sure bottom layer still lines up with tape marks on garage floor
   • Make sure bottom boards are butted against each other with no gap.
   • Make sure middle boards are butted against each other with no gap.
   • I found a rubber dead-blow hammer to be helpful here in making small positioning adjustments, and a small crow bar helps in tight spaces, like moving pieces away from the wall.
4. Place match marks (middle to bottom). This way any subsequent shifting can be detected and corrected. Vertical Sharpie marks at periodic locations around the perimeter will do the job.
5. Mark hole positions (corresponding to each “X” on the hole map)
   • Review hole map to evaluate where chalk lines should be placed to help mark hole positions.
   • Move around the perimeter, taking the necessary measurements with a combination square to indicate where screws must be positioned relative to edges. Mark just enough holes with the square to allow a chalk line to be drawn across in the right places. For example, we marked the bottom-left corner hole then the top-left corner hole, and snapped the chalk line across them so we could easily mark the holes in between.
   • Don’t mark any interior hole locations yet.
   • Use the chalk line to lay down a grid on the middle layer, based on the screw positions indicated in the previous step. This makes the interior screw positions much easier to locate and mark. It also creates a much more consistent hole pattern. It’s important that the middle-layer screws are precisely located so they do not interfere with the top-layer screws. We were obviously not be able to see the middle-layer screws once the top layer is on.
   • Review the hole map to ensure all interior holes are on chalk lines. We had to add a few more lines. Measure and make pencil marks on the perimeter to locate these additional chalk lines.
   • For all holes located on a chalk line, pull a tape measure along the line to indicate where those should be marked. This is where the prep work paid off because it’s much faster just measuring in one direction instead of two. In many cases, the holes even ended up at intersections of chalk lines, making things even easier.
6. Put weights on the platform to reduce risk of the plywood shifting out of position.

7. Double check positioning and seams (refer to match marks and garage-floor tape).
8. Drill pilot holes at each “X” marked (5/32” diam, 7/8” depth). Use a drill stop to keep from over-penetrating and dulling bit on concrete floor. Drilling pilot holes is optional, but I found it reduces the chance of splitting the wood or pushing apart the platform layers when driving the screws. It also makes screw-driving much faster, and the screw is more likely to stay straight.
9. Move one middle board off the stack.
10. Apply Liquid Nails adhesive on the bottom layer where the middle board will mate.

11. Put first middle board back in place.
12. Double check positioning and seams (refer to match marks).
13. Replace weights on middle board, starting from middle and working out to perimeter.
14. Install screws, working from middle and working out to perimeter. These should be installed while adhesive is still wet. The weights should be left on the platform as much as possible, working around them to place the screws. Set the drill’s torque-limiting clutch (if equipped) low enough to prevent sinking the screw heads. Start at low torque and increase slowly to dial it in.
15. Repeat process for second middle board (remove it, apply adhesive underneath, replace, realign, replace weights, install screws while adhesive still wet).
16. Allow adhesive to set overnight (weights still on top).

17. Mark locations of middle-layer concrete anchors (corresponding to each “*” on the hole map)
18. Pilot drill for concrete anchors:
    • Use regular drill with 3/16” regular bit to drill through wood only. Stop at 1-1/4” deep (use drill stop).
    • Use hammer drill w/ 3/16” masonry bit to drill 3” deep (total including existing platform thickness)
    • It can help to countersink these holes so the anchor head sits flush. I undersized it so that the anchor still had the full plywood thickness in grip though.
19. Install the middle layer’s concrete anchors.

20. Remove weights from the platform.
21. Position top boards on middle layer in proper alignment.

22. Place match marks between top and middle layers. Also, mark outline of top boards on middle boards.
23. Put weights on top layer.
24. Mark hole positions (corresponding to each “O” on the hole map). I did not use chalk lines here since it’s the top (visible) layer, and the stain was yet to be applied.
25. Double check positioning and seams.
26. Drill pilot holes (5/32” diam, 7/8” depth).
27. Remove one top-corner board.
28. Apply Liquid Nails adhesive for first top-corner board.
29. Put first top-corner board back in place.
30. Double check positioning and seams.
31. Put weights back on, being careful not to move board out of position.
32. Install first top-corner screws.
33. Remove top-main/center board.
34. Apply Liquid Nails adhesive for top-main board.
35. Put top-main board back in place.
36. Double check positioning and seams.
37. Put weights everywhere, starting in middle, being careful not to move board out of position.
38. Install screws.

39. Remove other top-corner board.
40. Apply Liquid Nails adhesive for second top-corner board.
41. Put second top-corner board back in place.
42. Double check positioning and seams.
43. Put weights back on, being careful not to move board out of position.
44. Install second top-corner screws.
45. I accidentally marked (and drilled) a few holes wrong on the top layer, so I used wood filler and toothpicks to fill them in.

Drill Rack-anchor Holes

Then it was time to drill holes for the rack anchors before the platform is stained. I followed this plan:

1. Position one upright of rack on platform.
2. Mark rack position on platform w/ pencil. Pick a longitudinal and transverse “datum” to measure from. I wanted to take measurements from the same two edges since the platform wasn’t perfectly aligned, despite best efforts. I picked the most-flush corner board as transverse datum and the “top” edge of the middle board as longitudinal datum.
3. Once rack upright is positioned, start 7/16” holes in platform, drilling through the rack flange’s holes.
4. For any rack holes that can’t be reached with drill through rack, mark them as precisely possible with the pencil. I traced the inside of the rack hole against the platform. Later, I located the center by drawing perpendicular diameters after upright was out of the way.
5. Move first rack upright off platform.
6. Position second rack upright.
7. Mark rack position on platform w/ pencil. Take measurements relative to the same datum references as other upright. Use nominal rack width to locate this upright in transverse direction.
8. Drill and mark holes the same way as with the first upright.
9. Move second half of rack off platform.
10. Drill all rack-anchor holes all the way through platform only w/ 1/2” bit. Stop at 2” deep. These are clearance holes. The anchors are 3/8” diameter, and I didn’t want them threading into the platform on the way down. To the extent possible, I wanted them to pass through freely and put the full platform thickness in compression. Reference Titen HD recommendations for fixture hole size (it’s 1/2”-9/16” for 3/8” anchors).
11. Use hammer drill to drill 3/8” holes into concrete.
    • Hole depth from platform surface: 5” (fastener shank) + 1/2” (recommended overdrill) – 3/8” (rack flange thickness) = 5-1/8”. I found I had to drill a bit deeper than this for the the fastener to run all the way down (most likely extra debris left in hole).
    • Follow the hammer drill’s instructions regarding duty cycle of the bit. If used too long continuously, it will heat up and wear prematurely. I was able to do each hole in less than 30 seconds total and without pushing on the drill at all. If it’s taking much longer than that or the drill bit isn’t “pulling itself” into the material, the bit is either worn out or (more likely) the drill is inadequate. A hammer drill is a jackhammer first and a drill second. It should be pulverizing the concrete and using the flutes to remove the debris. It does not “cut” the concrete like might be expected based on experience with metal and wood. Note how the tip looks like a chisel. How well it works has more to do with the drill’s hammering ability (size and price are indicators) than any sharpness of the bit.
    • Stop a few times while making each hole to remove debris, alternating sucking with a vacuum and blowing with a blow gun attached to a compressor. When the debris had climbed up the flutes enough to reach the hole surface, I took that as the indication to pause and clean out the hole. Too much debris will wear the bit out faster.
    • I used the “tail end” of my caliper to measure hole depth as I went.

12. Re-position rack on holes, check alignment. The holes lined up in my case.
13. Do not bolt rack in place yet.

Apply Stain to Top Layer of Wood

1. Mask off things that shouldn’t get stain on them.
2. Follow the stain’s instructions regarding application, dry times, number of coats, etc.
3. We stained the “inside” edges and sides of the top layer (the edges the rubber will butt up against) so that no light-colored wood showed through when the rubber was installed. We also stained the surface of the middle layer along a ~1/2” border adjacent to the top layer for the same effect.
4. Additionally, we stained the visible sides all along the perimeter of the platform – all three layers.
5. I’ve heard some people have success mixing sand in with the stain to provide better grip, but we didn’t do this.

Install Rubber Mat

1. The rubber mat must be cut in half longways to fit on each side of the platform’s top wood surface. The mat is not exactly 4’ wide, so it must be cut longways at least twice to size each piece right.
2. The mat is also slightly longer than 6’ (AND the corner hardwood boards were slightly longer than 2’, encroaching on mat space), so some length will have to be trimmed as well. I did these cuts after laying the mats into place.
3. I planned my cuts so I could put the factory edges against the platform’s top-layer wood. If there are any mistakes in the rubber cut edges, they will be much more noticeable next to the near-perfectly-straight wood edge than when positioned at the outside perimeter of the platform.
4. After trying a few less-effective techniques, here’s the best way we found to make cuts:
   • Lay the mat flat (not bent over a roll or anything) on a surface like scrap wood that is okay to hit when piercing the bottom of the rubber
   • Measure and mark the cut path with a chalk line. A small notch cut in each mat end makes a good string guide.
   • Lay the long edge of a framing square along the chalk line to help guide the cut, repositioning it as needed while working my way down the line.

• • I started each cut with a box cutter then transitioned to using a bare razor blade gripped with small vice grips (after the box cutter couldn’t reach through the groove fully).
  • Make long slices along the cut line, putting some pressure sideways against the square to maintain alignment (making sure to step on the square to prevent it shifting).
  • Do NOT peel the rubber apart while cutting. Even though this makes the cuts easier, it causes a significantly more jagged cut. By leaving the cut edges together, it guides the blade in the same groove for each successive slice. I did my first cuts w/ peeling, and they are much worse than my later ones when I used the square and kept the edges together.
  • Spraying the cut line with water makes the cuts a bit easier.
  • Once the rubber pieces are cut to the right size, lay them in place to check sizing one more time.

5. Measure and mark the hole positions on the rubber mat. I used a chalk line as before to set up distances from the edges, then I used the tape measure to indicate the holes along the line. Since a pencil or black Sharpie will not show up well here, I used a white paint pen. A silver or gold Sharpie should work, too.
6. I did not drill pilot holes in the middle platform layer to accept the rubber mat’s screws. I judged they were not necessary since the screws would not be plunging through more than one layer of wood. I did not pilot-drill the rubber mat either since it’s so soft and there’s a potential to accidentally oversize the hole.
7. I did not put adhesive under the rubber mats.
8. Check positioning and load up the mats with weights to maintain position. I also actively pushed the mats against the wood edges to minimize the gap while performing the next step.
9. Install screws in the indicated locations. I used washers under the screw heads to keep the screw head from sinking into the rubber. Again, adjust the torque setting on the drill to keep from blasting through the mat.
10. The chalk lines will disappear in a few weeks, or they can be rinsed off.

Install Rack Anchors

1. Position each rack upright and drive the anchors in with a socket wrench or other non-impact tool.
2. I could not locate a torque specification for these anchors, so I just went by feel using a 3/8”-drive socket wrench.
3. If the anchor will not drive all the way down, the hole needs to be deeper or debris needs to be removed. I had to deepen a few holes.
4. After the rack uprights are in place, position the rack’s crossmember (chin-up bar), install its hardware, and tighten everything down. I got the anchors mostly seated before tightening the crossmember hardware. Then after the crossmember was done, I fully tightened the anchors.

Install Resistance-band Anchors for Deadlifting [done 2 yrs later]

For banded deadlifts, we could set them up inside the rack, but with all the plate storage and other attachments, it’s too crowded. We lift exclusively outside the rack nowadays. Dedicated deadlift platforms often have standalone band pegs, but they present a trip hazard. I wanted something that could detach or sit flush on the platform.

A boat “hatch pull” does the trick. It is meant to lie flat into a panel and be stepped on, and it won’t get damaged by debris falling into it like some internally-threaded insert would.

1. Take measurements on back side and plan how to make cuts.
2. Use chalk line to mark cut lines.
3. Use razor blade to plunge into mat and create the recess.
4. Test fit and fine-tune opening until the hatch pull fits in.
5. Fasten hatch pull down using longer screws than elsewhere on the platform since the flange adds thickness, and the anchor has to resist pulling force. I used 2″ screws so they would get into the bottom layer of wood.

Things I Would Do Differently

• I would have used washers under the rack anchors. Proper installation should include a flat washer and something like a split lock washer. Without the split lock washer, the joint is much too stiff (allowing it to lose clamp load when disturbed – from thermal cycling, wood relaxation, etc.). I put a wrench on it every few months and can get a few more degrees of twist. Simpson Strong Tie says not to reuse the anchors, so I am leery of removing them to add washers. Even if I were to replace the anchors with new ones, I am more worried about the concrete disintegrating during removal.
• I would have gotten a good hammer drill from the start. I initially used a weak one to pilot-drill for the middle-layer concrete anchors. I originally planned to place many more middle-layer anchors but didn’t because each hole was taking 30 minutes and 3 masonry bits. I thought it was the fault of the bits or my technique, so it tried a few brands of bits with no luck. Through some internet research, I finally started to suspect the drill. I finally got a larger SDS hammer drill to do the rack-anchor pilot holes, and the difference was incredible. By then I was too far along to go back and place more middle-layer anchors. I did all the 3/8” holes with a single bit that still looks new.
• Related to the above, one edge of the platform has begun to lift from the garage floor just barely (1/16” maybe). I’m sure that wouldn’t have happened if I had used more middle-layer concrete anchors like I originally planned.
• I can sometimes hear a clicking noise under one part of the platform that I believe is adhesive failure, so we may have done something wrong there during assembly that led to the slight separation.
• I’m not sure if I regret this or not, but the use of adhesive between the layers will make relocation interesting. I’ll have to use a hole saw to access one of the middle-layer concrete anchors. The other two are easily accessed under the rubber mats.
• I would try adding sand to the stain for better bench-press leg drive. I have to put a yoga mat under the bench foot (and my feet) to get enough grip.
• I would have made every cut on the rubber mat using the technique described in the procedure above. I initially followed some videos’ advice (and my intuition) and bent the rubber while slicing along the cut line. This resulted in an ugly, jagged edge even though it was slightly faster.

Misc Research

Other builds:

• DIY Weightlifting Platform with Squat Stand Attached | Garage Gym Reviews
• Garage Gym Weightlifting Platform DIY | Leo Pando on YouTube
• How to Build a (Really Solid) Weightlifting Platform | All Things Gym
• Setting Up a Home Gym | Starting Strength
• How To Build Your Own Deadlift Platform w/ Your Logo | Alan Thrall on YouTube
• Building A Weightlifting Platform | Alan Thrall on YouTube
• How to Build a Weightlifting Platform | Art of Manliness
• How to Build a Weightlifting Platform | Catalyst Athletics
• DIY: How to Build Your Own Deadlift/Olympic Lifting Platform | BarBend
• How To Correct a Slanted Platform | Alan Thrall on YouTube
• How To Level a Sloped Platform | Kratos Strength Systems

Simpson Strong Tie specs and recommendations

Installing Tapcon concrete screws:

• Tapcon PDF
• Min 1” deep (into concrete), max 1-3/4” (so 2.5-3.25” long screw) – chose 2.75”
• 1/4” screw diam requires 3/16” pilot hole – drill 1/4” deeper

Platform Supplies

Tools

Hole Map Template

(click image to download XLSX worksheet)

Hole Map Example