I’ve been working slowly, but surely on adding a bit of curb appeal to Mom and Pop’s front yard. The beautifying started with laying this stamped concrete tiled driveway…
The driveway was followed by installing a new elegant (and really cool) locking mailbox…
…along with planting some perdy flowers for some more curb appeal.
I’m pretty proud of my little mailbox garden. Although, if you’re a gardening person you’re probably laughing your petunias off at it. But what can I say? I’m a city girl here (which probably explains my love of concrete) and anyone else who’s grown up in NYC will tell you that green only grows in fairytales.
But I’m doing my best to green up these brown thumbs, and that’s led me to my latest project: a brand spankin’ new, drop dead gorgeous (if I do say so myself) concrete planter.
It’s another small step toward fairytale green, while incorporating some concrete love. And I do mean love cause it turned out better than I could have imagined. So I’ll take you through the steps to get your own green on with a gorgeous DIY concrete planter.
Building A Concrete Form
The process starts by building a form. Basically, you’re making two box forms. The larger/outside form gives shape to the outside of the planter and the inside form gives shape to the inside of the planter and the concrete is poured in between the two.
Generally, when building a form for concrete you use melamine board, which I did use for the outside form. But for the inside form, the parental units had this old laminate cabinet thingy that was going to be trashed…
So I figured, why not recycle it and use it for the inside form. I would have used it for the entire form, except that the width was just a little short for the dimensions I wanted.
Now, let’s get into the steps.
1) To build your forms, cut your boards to the following dimensions:
Four Sides: 15″x18″ each
Four Sides: 12″x15″ each
Cut Two: 14″x14″ with 3″ corner cut-outs (instructions below)
For safety, be sure to always wear goggles when cutting and to always clamp down the pieces to be cut.
Here’s the cut pieces for the inside form…
2) I filled in the little holes with wood filler and then used a brad nailer (1-1/4 nails) to put together the inside box form.
If you don’t have a brad nail (I just got mine. Yay!), you can screw the pieces together instead.
Here’s my inside form…
3) Repeat the process, with the appropriate dimensions, for the outside form. (I used the melamine for the outside form.)
Once the two box forms are complete, you can choose to stop there or you can add legs to your planter. I chose to add legs.
4) To create your legs, cut two 14″x14″ squares and then remove 3″x3″ squares off the corners.
The removed 3″ corners will create the shape for the legs and the rest of the board will be negative space. (You’ll see what I mean below.)
It’s a good idea to clamp both 14″x14″ squares together when cutting so that the two boards are cut completely flush.
5) Once you’ve cut out the 3″ corners, nail (or adhere) the two boards together and cover the cut out corners with some PVC tape so that the finished corners will turn out nice and smooth.
The leg cut-outs will get dropped into the larger outside form. You can visualize here how the corner cut-outs create the space for the legs…
6) Before attaching your leg pieces to the outside form, caulk all interior joints on the form to prevent the wet concrete from seeping through your form joints. To do so, run a bead of caulk down each joint…
Then use your finger to smooth out the line.
I recommend using a colored caulk (I used black) so you can better see and ensure that you have smooth caulk lines. Any lumpiness to your caulk lines will show on the final product, so do your best to make the lines nice and smooth. It can sometimes take a little practice to get the best caulk lines, so if you’re not completely happy with your lines, while the caulk is still moist you can dab a little mineral spirits on a paper towel to help smooth out your lines.
TIP: Use colored caulk for easier visual.
In the above image, you can see some dark areas on the melamine along the left side lines. Those are where I used my mineral spirits trick.
Somehow I managed to do much better on the right side of my form and didn’t need any additional smoothing after using my finger.
TIP: Use mineral spirits to help smooth a caulk line.
7) Attach your leg forms to the bottom of the melamine box and caulk all the joints…
8) On the inside form, caulk all the outside joints….
And smooth the caulk with your finger.
It’s not as imperative to get perfectly smooth caulk lines on the inside form because no one will ever see the inside of the planter since it will be filled with soil/plants. So don’t sweat it.
9) This step is optional, but I chose to add decorative boarders to my planter.
The boarder is simply a textured paintable wallpaper boarder. But anything that will leave an impression will work, so the sky’s the limit.
There are all kinds of textured wallpapers available online, but I found this particular one at Lowes.
To add the boarder, moisten the back of the wallpaper with water…
…and adhere to the inside of the exterior form…
TIP: Wait several hours for your boarder to dry.
Silly me only gave it about 20 minutes drying time, so when I started pouring my concrete, the boarder, which was not completely dried and adhered started to slip. I tried to tape it down to get it to stay in place. (You’ll see the black tape in the pictures below.) But it was a really big pain, so don’t do what this impatient girl did. Wait for the wall paper to dry.
10) Adhere a 1½” x 1½” x 2″ block of wood to the bottom form. (I used my brad nailer to adhere.) This will act as a spacer between the interior and exterior forms and after removal it will also be your drainage hole.
Mixing Your Concrete
Now, you’re all ready to get a’pourin’ your concrete. This is the fun part!!
11) First, get your work flow ready by gathering everything you’ll need.
Here are the needed items:
– Inside and outside forms
– Rapid Set® Cement All® (Two 55lb. bags) – Available at Home Depot
– Rapid Set® Set Control® (2 packets) to lengthen the time you have to work with your mix before it sets. – Available at Home Depot
– Rapid Set® Flow Control® (1 packet) to give your mix more flowability. – Available at Home Depot
– Water (3 gallons)
– Large bucket for mixing your concrete (I used an old planter container and duct taped over the drain holes. It was the perfect size.)
– Drill with mixing attachment. Make sure you use a high torque drill. Concrete is super heavy so there’s a very good possibility that you’ll burn out your beautiful high speed drill if you try using it to mix the concrete. You can mix manually, too, but I don’t recommend it.
I found an inexpensive high torque/low speed drill at Harbor Freight for $40 that I use specifically for mixing concrete.
– Bucket with water for cleaning drill/mixing attachment
– Smaller container for pouring the concrete. This is optional. I started my pour using a small container, but then quickly moved to using my hands.
– Utility knife or scissor to cut open Rapid Set Cement All bags
– Concrete color (optional) – The color I used is called Miami Buff (basically, it’s brown)
– Mallet to tap the forms to help settle the concrete and remove air pockets. Using a concrete vibrator table or rod would be optimal, but I don’t have either. You can also use an electric ander (without the sanding paper) to vibrate and settle the concrete. But the mallet worked well for my needs.
There are other items pictured that I had ready, but ended up not needing.
12) Mix your concrete.
The Rapid Set instructions call for 4-5 quarts of water per 55lb. bag. I used 5 quarts per bag (total of 2.5 gallons), but I found the mix still a little thick for pouring into the small space between the forms. So, since you’re not building a structural item where high strength is crucial, I recommend thinning the mix further and using 3 gallons instead of 2.5.
Tip: Add extra water to your mix for easier flow and settling.
To mix your concrete:
– Add the water (3 gallons) to your mixing container
– Add the Flow Control and Set Control
– Add optional color
– Add the concrete a little at a time while continuously mixing with your drill (or manually).
Tip: Do not pour all your concrete in at one time. It will be much too hard to mix, even with your high torque drill.
– After a few minutes when the concrete is mixed smooth, immediately dunk your drill mixer into the prepared bucket of water and run the drill. This will clean off your mixer.
Pouring Your Concrete
13) Pour the mixed concrete a little at a time into the bottom of the outside form until the concrete is level with the spacer you previously attached to the bottom of the outside form.
14) Insert and center the inside form.
15) Pour concrete down the sides, in between the two forms.
This part can get a little messy. You can see in the above image how thick my mix was, so in order to get my concrete down the sides, I had to push it through with a board of wood….
That’s why I recommended above to mix your concrete thinner than the indicated package instructions so that it’s easier to pour.
Also, notice the black tape on the sides of the form. I added that because I didn’t wait for my boarder to dry and firmly adhere to the form, so it started to slip a little.
16) If you have a helper, which I did, have them continuously tap the sides of your form with a mallet while you’re filling the form to help the concrete settle. If you have an electric sander, you can use that too to help vibrate the concrete down.
17) Once your form is filled, smooth out the top.
You’ll notice that my inside form is not perfectly centered. It moved a little while pouring, but the mix was too heavy for me to push it back into place. It’s not really noticeable on the finished product, but if you want to avoid this, before pouring you can insert an appropriate sized small block of wood on each side of the form in the space between the forms and close to the top. Then as your concrete fill gets close to the top for the forms, remove the wood spacers. This will keep your forms in place while pouring.
Tip: Insert removable spacers in between each side of the form while filling to keep the sides of your planter evenly proportioned.
Finishing & Sealing Your Planter
18) Once the concrete dries, use a chisel and hammer to gently remove the outside form. Rapid Set® dries quickly compared to traditional portland concrete products. So no need to wait several days to remove your form. I only waited three hours.
Once the form is removed, be aware that what you see will not look anything like the finished product. Adding the sealer is what will bring out the beautiful color of your mix, even if you simply stuck with the concrete grey color.
19) Very carefully use the chisel to remove the inside form.
I actually chose to leave my inside form in place because I had a square tupperware container that fit perfectly into the opening. So I decided to plant directly into the tupperware and insert that into the planter so that I can easily change out the plants at anytime.
20) There were some small voids/pits in my planter where the concrete had not completely settled. To fill them in, I mixed up a very small (about 8 oz or so), fluid batch of Rapid Set. I wanted the planter just a tad bit darker too, so I added a larger proportion of color to this mix, smeared the thin mix over the entire surface, focussing mostly on filling in any voids or pits.
Give your planter at least an hour to dry.
21) Seal your planter.
I used Ashby Super Seal. Mix according to instructions and simply brush it on. The sealer will go on white, but dry clear.
22) Don’t forget to remove the spacer/drain hole block that you attached to the bottom of the outer form.
I had a little trouble getting it out with the chisel, so I drilled it out instead.
And viola! Here’s my beautiful new DIY concrete planter!!!
The lighter variations in color on the planter comes from areas that received less of the second, thin, darker coat of concrete that I mentioned in step 20. I’m really diggin’ that look so on my next planter the plan is to be more purposeful in applying thinner areas of the darker coat.
Next, I harvested some plants from mom’s yard for the planter.
If you do thin out your mix (as recommended in step 12), you will get a smoother finish to your surface because it’ll be easier for your concrete to settle and you’ll have less air holes/voids. However, I really like the “imperfections.” It gives the planter a look of aged character. It was a accidental win, but I’ll take it.
I’ll be making a second, matching planter for the other end of the driveway soon. So one down and one to go.
And for more fun concrete projects…