DIY wall-mounted weight plate storage

A few months ago, when I left Zynga, I wanted to make sure I still had a place to work out. The Zynga gym isn't very big, but it's crammed full of awesome toys that are hard to find at most regular gyms, much less corporate ones: kettlebells, clubbells, climbing rope, olympic lifting platform, bumper plates, Dynamax medicine balls, Rogue barbells, plyo boxes...oh, and a staff that's cool with me grunting and yelling my way through Fight Gone Bad and then heckling me while I'm lying on the floor afterwards. Good times.

So I set about acquiring some new equipment for my home gym. Before long I discovered that floor space is at a real premium when you're in a 12'x12' space, and weight plates take up a lot of room on the floor, especially if you want to have easy access to them. A weight tree is nice, and not terribly expensive if you get it off Craigslist, but it only solves half the problem -- the weights are easier to get to, but they're still taking up valuable floor space.

I tried searching the Intertubes for wall-mounted storage plans, but surprisingly could not find any. So I set out to build my own. Here's what I came up with.

I should mention here that I am not an architect, structural engineer, contractor, or person with very much common sense. I am not responsible for any damage, injury, or unwanted side effects that occur as a result of anyone following these instructions. Proceed at own risk. While supplies last. Limit one per customer.

First, I wanted to do some research on what I'd actually need to hold this thing up. I'm currently the proud owner of 245 pounds of plates, and I'm planning on acquiring another 160 or so in the next couple of weeks (hooray bumper plates!). That's just over 400 pounds, plus the weight of the structure itself. I decided on a safety factor of 3, so I'm looking to build something that I think will hold 1200 pounds on the wall.

I'm going to be mounting this to studs, so that means lag screws. But how many and what kind? It's surprisingly difficult to find information on lag screw holding power without wading through a bunch of really technical documents. Eventually I found a formula that was believable:

W = 1800 * G^(3/2) * D^(3/4)

where G is the specific gravity of the wood that's holding the screw, and D is the unthreaded diameter of the screw. [Source] Values of G are here; divide by 1000 to get the proper units. I'm assured by my friend and super-handy-guy Mark that the studs in my house are almost certainly Douglas fir, but just to be safe I went with a G of 0.3, since that's lower than everything in the table save bamboo and balsa, and I'm pretty sure my studs aren't made of either of those.

Based on that, if I use 1/4" lag screws, I can very conservatively expect them to hold 100 pounds apiece, as long as I get 8x penetration into the wood. This gives the withdrawal force -- how much force it will take to pull the screw out of the wood. Note that if the studs are indeed Douglas fir, with a specific gravity of .53, we get withdrawal force of 245# apiece...but like I said, very conservative. I also found this PDF, which gives the shear force -- that's the force that will cause the screw to break. Since the shear force is greater than the withdrawal force, we're good to go.

OK, armed with that data, I put together my list of materials:

• 2 3'x4'x3/4" plywood ($25)
• 8 3/4" floor flange ($2.20 apiece, ~$18)
• 8 sections of 3/4" threaded pipe ($23, see notes below)
• 12 5"x1/4" Spax lag screws ($8)
• 32 3"x1/4" Spax lag screws ($10)

Total plus tax was about $95 -- about what you'd pay for 2 weight trees, but way less than you'd pay for something like this, and most importantly it'll be wall-mounted.

A few notes about choice of material:

• You could probably save about $10 by getting a 16' length of 2"x6" and cutting a few lengths of it, using 6 lag screws per board. I prefer the look of a solid sheet of plywood, but 2x6 is cheaper and easier to mount if you have a friend to help.
• 3/4" flanges are BY FAR the cheapest diameter. Originally I had planned on using 2" flanges and pipe, since that's the diameter of the hole on olympic plates, but it turns out 2" flanges are $15 bucks apiece. Ouch. Even the 1" and 1/2" flanges are twice the price of the 3/4".
• Home Depot will sell you a 10' length of 3/4" pipe for about $15, and will cut and thread it for 95 cents per cut/thread. I had them cut 5 8" sections and 3 10" sections; these turned out to be well longer than I need for the plates I have, but I figured I'd rather have too much than too little. One thing to note here is that cutting pipe takes FOREVER. At my Home Depot it probably took about 90 minutes to get everything done, and the oil from the machine gets everywhere. Make sure you get a plastic bag to put the pipe in, and dump out all the oil/wipe the pipe sections clean when you get home.
• As an alternative, you can buy pre-threaded sections off the shelf. I'd probably go this route if I were to do it again. It's way, way faster and not nearly as messy. On the other hand, it's a bit more expensive, and all the sections are threaded on both sides. I was worried about the threading scratching up the inside of my plates. You can also get end caps to help prevent that, but that puts a bump on the end of the bar that you need to negotiate when taking the plates off.
• I used Spax lag screws instead of normal lag screws mainly because they're self-drilling, which means you don't have to drill pilot holes, which saves a ton of time, and they've got serrated threads, which are supposed to go in easier, saving wear on your drill. They're a bit more expensive, but they have washers built into the head, so you save a bit there. I also like that you can get them with T-star heads instead of hex heads, which sit flat on the wood when you're done. You could probably save about $5-10 using regular lag screws and washers.
• Also, I used 3" lags on the flanges only because they were completely sold out of 2" lags. If they had those, I would have used them -- they're a bit cheaper and just as good since the flanges are only being held by 1.5" of wood.

OK, materials done, on to the actual construction!

I bought a 4'x8' section of plywood and had Home Depot cut a 1' strip off the side, then cut the resulting 3'x8' in half to make two 3'x4'. Align the two 3'x4' together. Put the weights you plan on hanging on top of the board in the configuration you want; this will help you make sure the weights fit and that there's enough clearance around each weight to actually get your hands in there to put them on and pull them off. It helps a lot if you have a big piece of cardboard to draw on, like so:

I saved this from a large mirror that I bought for the gym. Yay foresight!

I put a few 1-1/4" screws into the two pieces of plywood to hold them together, but that isn't really necessary since you'll soon be putting the lags into both pieces. Place a section of pipe inside the hole of your plates and mark where the bottom of the pipe is, like so:

The hole should be wide enough where you can slide a pencil in and mark the bottom of the pipe.

Remove the plate and place a flange where you marked the pipe. Attach the flange to the plywood using the 3" lag screws.

Even though they say pre-drilling isn't necessary, I found it useful to put a very short 1/8" pilot hole in -- this helps the lag get into the wood to start, and makes it easier to put the screw in straight. Don't screw the lag all the way in! It's longer than the plywood is thick, and you'll damage whatever's underneath the plywood.

Once you've attached all the flanges, you're ready to hang the rack on the wall. Start by locating your studs; you'll want to make sure you put the rack into at least two studs, and you're better off with three (depending on where your studs are, this might mean having a different width of plywood). I found it a lot easier to rest the rack on a box, but if you don't have something of the right height, it shouldn't be too bad to have a friend hold it for you -- once you get the first 2-3 screws in, he can let go.

Put all the 5" lags into the wall first, then finish putting the 3" lags all the way in (the reason for this is that you want the rack as tight to the wall as you can get, and putting the 3" lags all the way in will make them stick out the back and make it harder to pull the rack flush to the wall). 

Screw in the pipe sections to the flanges. You can now test the holding power of the pipes -- just grab on to one of them and hang, and see if you feel any wiggling. Rack the weights and you're done! Go enjoy your newfound extra floor space -- I recommend some burpees.

Final result! Paint if you like.