In honor of election day, I’m re-using a bunch of political yard signs to build a small outdoor shed. The Coroplast used for high-end campaign signs is far too good to be tossed out just because somebody lost an election.
I’ve decided on the following method of construction:
- Coroplast campaign yard signs
- Stapled to furring strips
It’s every bit as complex as it sounds.
Below are two pictures of a small prototype. The left hand view is the panel with the back still open. The right hand view is the finished panel holding up a 15-pound barbell.
From an engineering standpoint, this is a “box beam”. The rigid Coroplast skins, separated by and firmly attached to the wood furring strips, create a lightweight, stiff panel. Just the same way that two thin wooden veneers, glued to a rectangle of wood, create a strong hollow-core door.
Note that there’s no joinery. The only woodworking involved is in sawing the pieces of wood to length. So this is a great project for the low-skill DIYer, or maybe for kids.
The bottom line is that this method of construction:
- Takes almost no skill.
- Is cheap, sturdy, and reasonably fast.
- Uses up many yard signs
- Provides some insulation as well.
That last bullet comes from the two sheets of Coroplast with an air gap between them. I’m guessing that these panels should have an insulation value of roughly R-5, in U.S. units, or about the same as inch-thick foam board insulation.
The biggest downside? Ugly. I thought this would have a sort of cute, crazy-quilt appearance. But the pieces (the signs) are too big. So, instead of crazy-quilt, the look of it is straight-up shanty-town. Particularly when this is just a big rectangular solid. I’m probably going to have to paint this shed, to have it blend in with my suburban neighborhood.
Details on building the panels follow.
I’m now about halfway through with the build. My plan is to keep adding to this post until I get to the final (for now) shed.
Composter shed: Dimension, tools, materials.
Construct five flat panels
The shed consists of four side walls and a flat top. Dimensions are:
- 3.5′ tall
- 3′ wide
- 2.5′ deep
That means building the following:
- 2 panels, 3.5′ x 3′ (front and back)
- 2 panels, 3.5′ x 2.5′ (sides)
- 1 panel, 3′ x 2.5′ (top).
For the first part of the build — making the walls and top — you will need these tools:
- Tape measure and marker.
- Hand saw (or table saw)
- Staple gun (manual is fine)
- Utility (Skil) knife.
By “staple gun” and “staples”, I mean the kind you find in a hardware store (e.g., Home Depot reference). The only caution is that compact staple guns can’t use the larger staple sizes. I wanted larger (1/2″ staples) so I’m using a full-sized (Arrow T50) staple gun.
The bill of materials for the shed walls and top is:
- 12 eight-foot 1″x3″ furring strips…., $24
- 1 box of 1/2″ stainless steel staples, $13
- 1 tube of caulk ………………………………….$3
- 40 1.5′ x 2′ Coroplast yard signs ………$0
The cash outlay so far is $40. But I could have gotten by for about $20 with no loss of functionality.
(I used 1 x 3 furring strips only because my local Home Depot didn’t have the cheaper 1 x 2 strips in stock. Using 1 x 2s would bring the $24 down to about $16. I used expensive stainless steel staples so that I’d have the option NOT to paint this when its done. In hindsight, given how it looks, I’m clearly going to have to paint it, so I could have gotten by with a $2.50 box of generic half-inch galvanized staples. Those two changes would have brought the cash outlay below $20.)
The amount of wood framing required depends, to some degree, on the size of the yard signs you are able to collect. Large signs can span longer distances and require less wood. The 12 8′ furring strips should be just barely adequate for using only 1.5′ x 2′ yard signs, for this shed.
I’m probably going to spend another $20 in hardware before this is done. I want to put this up in the fall, and take it down in the spring. And that will be a lot easier if I buy proper “drop-in hinges” instead of just screwing the panels together and resting the lid on top.
In theory, you could substitute a hammer and short roofing nails for the staple gun and staples. But stapling is fast, and you don’t risk splitting the thin (and crappy) furring strips.
A brief sign-harvesting interlude
The whole point of this project is to make use of a lot of Coroplast yard signs that would otherwise end up in the trash. This little composter shed requires about 40 standard (1.5′ x 2′) yard signs.
Turns out, I didn’t have enough, so my wife and I went out harvesting campaign signs. We went driving around looking for campaign signs that had been left on public property. Around here, those signs are basically a nuisance and a trash generator. Almost a week after the election, at almost every polling place we checked, there were still some stray political signs sitting on public property, either forgotten or discarded.
In addition, the Town of Vienna, VA maintains a permanent, rotating stock of such signs. We have an ordinance here that bars private signs in the public right-of-way. Town work crews remove any such signs that they see. My wife reminded me that (per rumor) these are always tossed into the dumpster behind Town Hall.
So that, if you live or work in the TOV, and you ever wonder where your signs have gone, and want to get them back, that’s where you look first. We went there last, just to round out the collection.
Construction just sort of happens
The only way I can describe the process of construction is that you just kind of mosey through it, using the square-cut corners of the yard signs to guide the assembly of the panels.
Start by cutting the longest length of furring strip. Here, that’s a 3.5′ piece that will form the vertical edge of one side or front/back panel.
Square up a yard sign to that piece of wood, and staple it on. Measure how long the next piece of furring strip needs to be. Cut that. Staple it to the yard sign. Make sure there’s some wood under every seam between two signs. Cut off any excess sign with a utility knife.
Flip the panel over and repeat.
The back side goes much faster than the front, because there’s no new wood placement involved. (In theory, to make this stronger, I should have “staggered the joints” so that the joints between signs appear in different places, front and back. In practice, these panels are far more than stiff enough without going to that trouble.)
All told, these took between 30 and 45 minutes per panel, depending on the size of the signs used.
Eventually, you end up with a panel that’s the correct size, covered front and back with Coroplast yard signs. And you’re done with that panel and move on to the next.
Here are the first three panels, destined to be the back and two sides of the finished composter shed.
Looking ahead
Well, this clearly works just fine. The Coroplast is firmly stuck to the wood, and the panels are light, stiff, and strong.
In addition to finishing the final two panels (front and top), I need to think about:
Caulk and paintFoam board insulation (maybe).Radiant barrier (maybe)Lift-off hinges (for connecting panels).
Paint. I’m going to leave this unpainted at first, just to see how it looks. But so far, it looks ugly rather than cute. So I’m likely going to paint the whole thing a solid, neutral color.
Insulation. It’s possible that the R-5 insulation of the existing panels will be adequate. But to achieve that, I really need to caulk the ends of the flutes (channels) in the plastic sheet, to keep the air inside from convecting.
And it’s possible that R-5 insulation won’t cut it. (I’ll go through some calculations in a later version of this post, but the only real-world test is whether or not the composter continues to function.) If not, I can always tack some foam board and/or radiant barrier to the inside of the composter shed.
Hinges. I could just screw the four panels together, and let the lid sit on top. But I’d like to make this so it’s easy to set up and take down. I’ve bought five pairs of “lift-off” stainless steel hinges, and I’m going to use those to connect the four sides and the top together.
Dedicated solar heater. Finally, if my composter continues to freeze up, despite this insulated box, I’m going to use the same construction techniques (plus a scrap of plexiglass) to add a small indirect solar heater. Just enough to inject a few hundred watt-hours of heat energy into the box, per day. Hoping to keep the compost active, instead of being frozen.
In the end, my wife pointed out a big sheet of double-pane glass that I’d had sitting around the garage for some years now. It was just the right size to form the front of the cabinet. That, some Gorilla tape, and a sheet of foam board for the top, and … it’s done. I’ll install the hinges when they arrive — because I don’t expect the Gorilla duct tape to hold in the long run — but that’s about it.
The composter is fully enclosed by insulating walls and top. The glass front faces south. I figure, if this doesn’t do it, then I’m giving up on the notion of composting my kitchen scraps through the winter.
