Let me start by saying that if you are not at risk for eviction from noise complaints, you should stop reading and deadlift on a floor without these pads.
That said, these work really well to dampen sound from percussion and translation as the bar is set down after a deadlift.
Here’s the before and after:
Materials required per pair of pads:
-18”X24” plywood (4)
-2” thick - 17”X23” high density ethylene foam (2)
-1” thick - 18”X24” high density ethylene foam (2)
-Vinyl of any color 24”X48” (2)
-4.5” 1/4-20 bolts with the heads cut off (8) or 1/4” rod that you can cut to size and thread
You can get the foam and vinyl at Joann Fabrics. Make sure you check on your phone for coupons while you wait in the checkout line. They always have coupons online and the checkout at Joann’s always takes 5-15 minutes.
You need two pieces of plywood per pad. The base is shown below as a draft. The second plywood layer is the same as the first layer, but with 3/8” holes instead of 3/16” holes.
After you have the pins ready, thread them into the base plywood. Do not over-tighten them or the threads created by the pins (threaded rod) will strip.
Align the 2” foam over the pins and press each one into the pin until the foam is pierced. Do not try to do all four at once. Do one at a time and take your time.
Set the second layer of plywood on top to check for fit. The pins should fit into the holes on the second layer of plywood without clearing the top of the hole.
At this point, you should check to make sure you’re happy with how it works. I dropped 135lb on it from standing and that was a good enough test for me. Keep in mind your load conditions. Someone deadlifting 700lbs is going to need thicker or wider foam than someone only deadlifting 200lb.
Round over the edges of the second layer of plywood to make sure the edges don’t tear the vinyl in the next step.
Place the top foam pad (1” thick in this case) face down with the second layer of plywood facedown on top of it with the vinyl on the bottom. Cut the vinyl oversized then staple it to the back. Don’t pull it too tight. It’s better to have too much vinyl than too little - you can always cut it away after you staple it.
Now just flip the top section over and put it over the pins on the bottom section. You’ll notice that the top part just sits there. It’s not actually attached. It’s important that they are not attached vertically.
Finally, use a utility blade to score the four corners of the vinyl. This will allow the air to escape from the foam when it is compressed, instead of it breaking at other parts of the vinyl.
Final notes and considerations
Make sure you consider the load you are using. You may need thicker foam for heavier loads or thinner foam for lighter loads. I have anecdotally noticed that this foam has two part elastic properties; the foam is relatively stiff until a load threshold (about 100lb in the build above). Once that threshold is exceeded, it seems to deform linearly until it bottoms out.
For a more robust build, change the second layer of plywood to 1/4” steel plate or 3/4” solidwood.
You’ll notice that this creates a height change on the deadlift and essentially makes it’s a pull from blocks. This is why, if you can deadlift without them without being evicted, you should. However, in order to counteract this, measure the resting height of the system (in this case 4.5”) and get enough plywood layers to stand on (in this case, 6 layers = 4.5'“).