This modern looking concrete pillar with backlit LED house numbers will make your neighbors jealous. In the article, we will cover what you’ll need to make this project, some tips for choosing material, help with mixing the concrete and using a skim coat to make the project look good.
Below is the corresponding video to show you how to make the project and fix things when they go wrong.
The download for the Sketchup drawing I used in this project is near the end of the article.
Below are most of the items needed for this project. I didn’t list the tools you’ll need or the optional things like paint and water proofing materials.
- (4) 50lb bags of Quikrete 5000
- QT Home House Numbers
- 4’ x 4’ sheet of ¾” concrete form material (see below for Concrete Form choices)
- ½” concrete form material (see below for Void Area choices)
- 2” screws for form building
- Concrete reinforcement – either wire mesh or rebar
- At least 1” diameter steel tube (optional for post)
- Polyurethane Construction Adhesive
- Solar Strip Light
- ¼” Irrigation Tubing
Choosing Material for the Concrete Form
In the video and instruction, I’m using some hobby grade ¾” plywood I already had. Your choice of concrete form material will affect the texture on your final project. If you use plywood with a heavy grain pattern on it, there is a chance that pattern will show up in the concrete. Using something like a melamine coated particle board will produce a smooth surface.
Choosing Material for the Void Areas
I learned this this hard way. There is a really good chance the void areas will not come out cleanly when you remove the form. I used some 1/2” plywood in my first experimental pillar. The void area separated from the form and I spent a good amount of time chiseling out the plywood. I’d recommend using ½” rigid foam. Even if you have to remove it from the void, it’ll come out way easier than plywood.
LED Solar Mechanism Void
We need to create a void in the top of the pillar that the LED solar mechanism will sit in. When you measure out the void,
- You want the solar mechanism to sit snugly on the sides in the void when you’re done.
- Leave yourself between ¼ – 3/8 inch of space at the bottom where the mechanism will sit. This will give you some wiggle room for the cables.
Learn from my mistakes.
- Make your void out of rigid foam. It took a bit of time to get that wood block out of the concrete 😊
- Measure a couple of times before making your void. Although it’s a learning experience to chisel out the void to fit, you probably don’t need that question going through your head, “Am I going to mess this up?” That’s what was going through my head for sure.
If you are unfamiliar with mixing concrete, the video below is a good place to start with fundamentals.
In this project I used Quikrete 5000 mix in 50lb bags. The subsequent information is specific to that. Here are the manufacturer’s instructions and specifications.
How Much Water Should I Use?
The manufacturer’s instructions say that you should use 6 pints of water per 80lb bag of 5000 mix and not to exceed 10 pints. Why is there such a range? If you watched the video, it stated that the more water you use the weaker your concrete will be. The manufacturer is saying that 6 pints is the ideal amount of water to use but realizes that you might need more to get the concrete to the workable consistency you need for your project.
So, with a bit of simple math, this means that for the 50lb bags I used in the project video the range would be 3.75 – 6.25 pints of water. I know, who uses pint? Here’s a conversion to make it easier.
3.75 – 6.25 pints = 7.5 – 12.5 cups
If that’s still too much and you’re an eyeballing it type of person, you can use anywhere between
½ a gallon to less than ¾ of a gallon of water
Just remember to add a little bit of water at a time after that minimum recommended amount to get the concrete workable. You’ll be surprised at how it will all of a sudden come together.
How Long Should I Wait Before Taking the Concrete Out of the Form?
You might assume that by using 5000 psi concrete mix means you get 5000 psi in compressive strength as soon as you see it harden in the form. That is not the case. For any concrete mix, the rated compressive strength is after 28 days of curing.
You can see how this concrete mix cures and its compressive strength in the chart below.
When you are doing this project, the minimum time I would let the concrete sit in the form would be 3 days. This will get you to 50% of the strength. Even then, I would wait till the 7th day before removing foam out of the void areas to be safe. Better to wait and get minimal chip out on the void corners.
What if I Need to Apply a Smooth Coat to Fill Small Air Pockets?
The mix I used for my skim coat was.
- SikaLatex Concrete Bonding Adhesive and Acrylic Fortifier
- Portland Cement
The concrete bonding adhesive instructions tell you to use it like water when mixing it with a cementitious, fancy word for cement like, product. I mixed this with the Portland cement until it was the consistency of pancake batter.
You can use a drywall joint knife to spread the skim coat. There were some areas like inside the number void area that I had to apply the skim coat with my hands and scrape the area smooth.
Let the skim coat set till the next day before sanding it.
How do I Re-Connect the Wires?
There are a couple of ways to reconnect the wires after you cut them. The video below goes over a number of ways you can connect wires.
Painting in the House Number Void
When I initially set the house numbers in the void, it became quickly evident that something needed to be done to make the numbers more visible, either paint the numbers or paint behind the numbers. I liked the stainless look of the numbers, so painting behind them it was.
I decided on using a porch paint instead of masonry paint designed for vertical surfaces. I’m sure you could use either one with success, but porch paint is designed to be walked on and exposed to the elements. I’m hoping the extra durability of the porch paint will translate into a longer lasting product.
I don’t have a brand preference but wanted a paint that didn’t have a gloss finish. A high gloss paint behind the numbers would detract from the numbers.
Installing the Numbers
Here are some tips for installing the numbers
- Mark a center line as a reference.
- Use the installation spikes for the house numbers on the center reference line.
- The number 1 was an odd one. My first instinct was to center it but keeping with the tip above I think it looks better offset a little.
- Do as many test layouts as you can and get your significant other as another set of eyes.
- Use a nail to create a divot for your drill bit to go into. This will keep your drill bit from moving around.
- Start with the outside numbers and work your way to the center.
This is the Sketchup file used in making the concrete pillar for the house number project. There are 2 fronts for the form, one for 3 house numbers and one for 4 house numbers. You will need to unzip the file after downloading it.
You can view this file using the SketchUp Desktop Viewer.
This project file is licensed under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0).
Please use the following for attribution
Adventures In DIY – Make an Epic Concrete Pillar with Backlit House Numbers
This modern concrete pillar with backlit house numbers really pops in the day and night time. Last bit of advise, there are a couple of settings for the LED lights. You’ll have to select the constant on setting unless you want to mess with people and have them flash on and off every half second. Make sure you subscribe to our youtube channel and this website to make sure you get the latest content.