Building a Massive Shed by Dumpster Diving

Quite a lot of good materials can be found discarded in the large dumpsters of construction sites. So long as they don't mind you doing a bit of dumpster diving, it's a win for absolutely everyone. They have to pay to have the dumpsters emptied and returned (not that that's realistically much of a consideration for them), you get tons of great stuff to work with, and everything you take stays out of the landfills. At the end of the day, you're doing a small part to help out the environment while also ending up with an awesome shed. Wins all around, I say!

Supplies are realistically whatever you can find, but there are some crucial core pieces to look for:

• 4 long, solid boards that can be used as your foundation border
• 4 long, solid beams that can be used as your 4 posts (or long 2x4s that can be attached together as long 4x4s)
• Something that can be used to protect your roof from the elements
• Something that can be used to protect your walls from the elements
• Lots of plywood
• Lots of 2x4s
• Something you can use as a door!

It's also ideal to be on the lookout for a window so that the shed can have some natural lighting, but many sheds don't have them and it would, admittedly, be easier to build the walls without having to navigate around windows.

The more you find, the more options you have for your shed design! Plus, whatever you don't use can get stored in the shed you're making :).

You need your materials, and if you’re making a shed out of stuff from the dumpster, then you already know where to go to get the goods!  Just make sure it’s ok with whoever is in charge of the dumpster.  In my case, there were townhomes going up nearby and there were several dumpsters constantly getting filled.  I talked with the people there, including the guy in charge, and everyone was super nice.  At a couple points they even helped load some stuff directly into the car when they knew I wanted what they were otherwise going to toss in the dumpster!  Makes sense, but it’s still nice.

It makes sense to get materials first anyway, but there’s also not really a template to follow when you’re working with salvaged materials.  So, finding what you have to work with is the first step to coming up with some semblance of a plan.

The first part of the shed is the foundation border, so be on the lookout for 4 nice boards that are solid and long which can be utilized for the border.  Then, you can look to get started!

Unless you’re somehow managing to get enough to build your whole shed super quickly, be sure to store your wood somewhere that protects it from water damage.  

If you're making a smaller, more manageable shed, this won't apply to you so much. However, if you're also looking to build a massive shed, it's unrealistic to be able to plan out every aspect of the shed from the get-go, especially if you're still collecting materials. There are way more pieces of irregular lengths than any sane person designing a template would ever incorporate.  It goes without saying, though, that you can’t exactly just easily tear it all down and start over, so you want to be sure that each stage is done in a way that makes sense.

With each phase you want to be thinking ahead to whatever comes next. Having a vision of what the shed will eventually look like also helps. For instance, where do you want the water to go? In my case, I wanted the water to all run off toward the creek, so I had a roof that sloped in one direction. This meant that I needed my corner beams to be cut at an angle at certain points so that I could eventually put the roof on how I wanted it.

While dumpster-shed building is clearly something that changes wildly on a case-by-case basis, I'll make an effort not to be too vague and will break down notes on each of the sections.

Building directly on the dirt is a no no, so we've got to start with a foundation of some sort. It's also worth noting that if you can add a stable sub-surface (concrete pad, crushed stone, etc), it will extend the longevity of your shed as well. With a dumpster shed build, the classic wood foundation is what makes sense to me, since that's what you'll be finding a lot of. Use whatever you've found to be your best option for the foundation border, and that'll be what props the shed up off the ground. You do want to ensure that the shed is off the ground, but you also want to ensure that this is level and incredibly solid, so dig a bit of a trench around the border. Check that it's good and level approximately a hundred million times (possibly a slight exaggeration) to make sure it's good to go, because once you start building a shed on top of it there's no going back!

An easy way to keep tabs of where to dig your trench, you can use marking spray. Conveniently, I found some pink marking spray in the dumpsters! Just put the foundation border where you want it, spray at the base of it, and dig where you see the spray. It makes things much easier.

For the floor, I wish I had done it slightly differently. Even if it means buying a few 2x4's, it would be much easier to start with planks that can reach from one side of the border to the other. Then you have an inherently level floor and when you build your grid out of 2x4's for the plywood to eventually sit atop, it will be much easier. With that setup, you simply attach 2x4s to connect one long 2x4 to the next.

What I did was much harder, and I did it because I didn't have 2x4's that were long enough to reach from one side of the shed foundation to the other. It did/does work, however, so if you're feeling excessively frugal like I apparently was, it is a viable approach. I built out parts of the grid with smaller 2x4's and interconnected them as I went. I kept the floor level by putting pallets and boards underneath my floor grid. Eventually the floor interconnected and it all looked and felt solid. You'll also notice that I didn't fully finish the floor until much later in the project, which I did so that I could ensure that my walls and floor didn't get in each other's way since I wanted additional interior walls.

With each step, you want to think ahead to future steps, too. The way I built the floor allowed for me to more easily make the shed insulated, which requires an inner set of walls. Your shed almost definitely does not need to be insulated; I just thought it'd be fun. Just remember to consider where the 2x4's will be getting added for your walls when you're building out your floor so that you don't run into trouble!

If you're intending to also add your plywood for the flooring at this stage, just be sure to add your 4 corner pillars first!!

And now... We go up! Start with your 4 corner pillars. This is much easier with a second pair of hands, but there are always workarounds if no one is available. When you put a post in against the foundation border, ensure that it's vertically level. It's also much easier to quickly put all the pillars together when you first attach a 2x4 that's intended to connect from one pillar to the next at the top to one of the pillars. Then, you put in that pillar and as soon as the next pillar is in, you can double check the levels, and be able to immediately attach them at the top to ensure everything is connected correctly.

Just be sure to keep your roof plan in mind when adding your connective beams at the top. For instance, if we reference my design, I needed to saw my pillars down on one side in order to setup a sloping roof. If I had added connective beams across the top in the same spot all around, there would be no slope. Just remember whatever plan you have in mind and you'll be good to go!

Depending on the size of your shed, I'd recommend attaching more supportive beams across the middle as well. The extra support feels nice and you're likely working with smaller pieces of plywood than you'd normally get from Home Depot, so it helps to have additional places to attach plywood as well. For this part, just be mindful of where you intend to put a door or any windows.

Notably, it may be worth visiting step 5 (the door), before you add plywood, depending on your plan for the shed. Similarly, if you do intend to put in windows, now is the time to add the window frames (step 7).

Adding plywood helps flesh out the rest of where you'll want to put your supportive 2x4's. You'll need to have places to hammer in your plywood, so you'll end up adding a lot of supportive 2x4's across the structure, which is great. It's really 2 birds here, because you do want to have that extra support, and adding in these irregularly sized pieces of plywood just helps you define where those supportive beams go as you work.

Adding plywood is otherwise very intuitive and is one of the most satisfying parts of the project, because it's when your crazy structure starts to look like a shed. You attach the border of the plywood to the 2x4's of the shed frame and keep adding until your shed looks more and more shed-like!

Before anything else, please not that you should not use an interior door! It will deteriorate and look as sad as it will make you feel. We don't want sadness; we want a cool shed! So, you'll need to find an exterior door, or something that can be used as one. I ended up finding a sliding glass patio door, which does not have hinges. To use something like this, cut some 2x4's to be the same height. Additionally, cut a piece of wood that's the same thickness as what you're using for the door to be the same height, too. Paint the pieces of wood to match the door (or to be otherwise aesthetically appealing), if desired, before attaching them. Attach them to one side of the door with long nails. If you're using something with glass like I was, be absolutely certain not to screw through the glass or to screw in the pieces too tightly. It could break the glass.

Once your 2x4's are attached, you now have somewhere to work with for the hinges. Depending on what you're using, you may be able to skip the 2x4 step and just skip to adding hinges. Either way, add 3 hinges to your door with one directly in the middle, one toward the top, and one toward the bottom.

Ensure that whatever part of the shed you're connecting the door to is very sturdy. If it's not, go ahead and add more 2x4 supports to the frame in that section. Once you're certain you're working with something solid, screw the hinges into the shed frame and pat yourself on the back. You have a door!

Realistically, you may have to either get creative or buy some supplies here. I got incredibly, ridiculously lucky. When the construction project near me fully finished, they threw away a full roll of roofing paper and more shingles (I had already found some). I ended up only needing to buy one pack of shingles, and found it on a wild sale. Prior to this, I was looking around and mentally preparing to get creative in what I used for the roof. At the end of the day, it's all about creating a waterproof barrier such that your shed is protected from the elements. Plywood doesn't do particularly well with getting wet. Just be on the lookout for what you can use to protect your shed from the elements, and if you think you're going to have to buy supplies for this be on the lookout for good deals because shingles are typically very expensive.

Similar to the floor, use 2x4's that are long enough to go from one side to the other, but in this case you want to extend slightly past the frame. This is so that you can further protect the shed from rain and the like. Attach 2x4's across these boards to add more structural integrity. I'd also suggest adding additional boards beneath the roof just to be safe. Depending on where you are, you may need to bite the bullet and add full-fledged metal supports if you are in an area that gets a lot of snow. I live in an area that very rarely gets snow, so naturally it snowed a ton right after I finished this build. I'm happy to report that the roof stood strong, but I do think I would've added more support had I realized snow would be an issue.

If you're also going the roofing paper and shingles route, you first adhere the paper to the plywood all across the roof. Then you start at the bottom with the shingles and nail in the top of each shingle in a row across the roof. Then, for the next row, you ensure that the row of shingles overlaps with the lower row such that by the time you reach the top, you have a fluid and waterproof protective layer of shingling. Plus, it looks nice!

I put this as step 7 because this is the point at which I added the actual windows to the shed, just to be safe. However, incorporating the window frames is part of the wall building process. There's a bit of jumping around in the actual building process of the shed, so needless to say that can come across in the step-by-steps as well!

To add a window to the shed, pick where you want a window and which of the windows you've found fits best. Measure the window itself, and build a frame of 2x4's that has an opening that's just slightly larger than the window's dimensions. Double check that the window does, in fact, fit the window frame before adding it to the frame of the shed itself. I tried a couple of tactics for fitting the windows, and the easiest way to fit windows in was to cut thinner pieces of wood to fit the frame and have them on the outer section of the window frame. That way, you put the window in place by just pushing it up against those outer pieces. Then you can fit the window in place by using your best insulation option and adhesive, and you can additionally add a similar inner frame on the inside to create what's effectively a window sandwich to keep it snugly in place.

My assumption is that whatever dumpsters you're working with are associated with builds, and whatever builds are happening need to be safe from the elements. When you walk by a work-in-progress building, sometimes you'll see siding covered with this massive paper stuff. That's essentially a waterproofing layer, and I do wish they had thrown some of that in the dumpster for my project. Either way, there's something being used to protect your plywood from the elements, and you can look to do the same. Some wood also is treated such that it doesn't call for the same level of protection.

In my case, while I do wish I had an additional waterproof layer, I added a full set of siding all around the shed to create a protective barrier. Plus, it looks really nice! In my opinion, anyway.

This part varies wildly based on what you have to work with and what you want to do with it, so I'm consolidating this into one section. For mine, I went all in and added the insulation and inner walls, which I then painted. This is super unnecessary, but I'm happy with the end result. Instead of the plywood floor look, I found some cheap ($5) vinyl flooring rolls from the ReStore to put over it. I also added build-in shelving, aesthetic-only (non-functional) shutters for one of the windows, and a cheapo solar light to the front in case I need to make my way to the shed at night. I also put in some molding I found inside the shed, and prettied up the front window with some nice, white boards.

Either way, at this point the shed is basically already done, so this is just making it look and function how you want. In other words, congratulations on finishing your shed and enjoy making it extra cool! Then it's on to storing all the stuff you wanted the shed for in the first place, and probably some excess pieces you collected from your scavenging adventures.

At the end of the day, I paid for some screws, nails, the long 2x4's for the roof, plywood for the roof, the cheap vinyl flooring, one pack of on-sale shingles, and other cheap odds and ends such that I can comfortably say I spent under $100 for what is now a massive shed.

Hopefully that all helped, and good luck on your build!