How to Make a Concrete Coffee Table
Concrete tables will transform your home and add a high end look to any room. In this article I will show you the process of creating a concrete table with an old world look. To get this effect, I use a trowel finish technique and acid stains to color the concrete.
In this tutorial I will explain how the concrete top is made. The wood base for the top is made out of pine and I made it similar to the coffee table tutorial on the site. The big difference is that 4×4's are used in this project and the size is much larger.
Orbital Sander – Dewalt makes a great orbital sander for around $50.
Drill – I use a Dewalt Drill
Table Saw – Optional (can use a circular saw instead)
Flathead screwdriver or chisel
Sanding Block with 100 Grit sandpaper (or a diamond pad).
Small Shovel (To mix Concrete)
Bolt Cutters (To cut wire re-enforcement)
- 3 to 4 bags of concrete (depending on size of table) – I use a 5000 PSI mix made by Quikrete which is commonly available at Lowes ($5/bag).
- Portland cement – You may have to buy a full bag for $10.00. It will last for a long time as you only need a pint or so per table.
- Wire Mesh – Pictured to right of concrete (Available in 4×8 Sheets) – $8.00 – You can also use Diamond Mesh
- Melamine wood or plywood – (Cut to the size you want your table. You'll cut strips to use on the sides of the mold as well. Available in 4×8 Sheets or smaller project size pieces.
- Concrete Bonder – Optional for using to mix with the portland cement slurry (can also use water)
- Rubber gloves
- A couple plastic cups to mix cement paste
- Tub to Mix Concrete in – (You can also use a big 5 gallon bucket)
- 1 5/8″ Drywall Screws to attach sides of mold
- 120 and 220 grit sandpaper for orbital sander
Let's get started!
1. Determine the size of table you'd like to make.
The table top Dustin and I made was 48 inches by 36 inches. The concrete thickness is 1.5 inches and the overall height of the table with the base is 18 inches.
2. Cut the bottom of the mold out of melamine or plywood.
This piece should be the exact width and length you'd like the concrete table to be. After cutting the base you'll need to cut the strips. For a 1.5 inch thick top the strips will need to be 2 1/4 inches tall. This accommodates for the 3/4 inch base.
3. Assemble the sidewalls to the mold
Attach the sidewalls using 1 5/8 inch drywall screws. Pre-drill to ensure the wood does not split. Use screws about every 6-8 inches.
I used 3/4 inch melamine for the base and 3/4 inch plywood for the sidewalls. You can use any type of 3/4 inch plywood when doing a trowel finish on the concrete top. I'd recommend using all melamine when building a concrete top using the reverse cast technique. Check out my reverse cast table top video here.
Use a bolt cutters to cut the re-enforcement down to size. You can buy 4×8 sheets of re-enforcement at Home Depot for about $9. Cut the re-enforcement about 2 inches shorter than the overall dimensions of the mold. Since my concrete mold is 48 x 36 I cut the re-enforcment to 46 x 34. This ensures you will not have metal sticking out of your finished piece.
Mix your concrete in a large plastic tub. Mix the concrete to about a peanut butter consistency. Simply add water to the mix as noted in the manufacturers instructions. If the mix gets to runny you can always add more concrete to dry it out. I mix a max of two bags at a time.
*If you are wanting to integrally color the concrete, now is the time. Quikrete stocks a few standard colors at the box stores. You can also find many more colors available from Cheng Concrete. I used acid stains to color the concrete after the table cured. (Instructions below)
Add concrete to the mold. An ice cream bucket works great for this process.
When creating a concrete table using the “pour in place” / right side up technique you'll want to fill it up about half way full or a little less than halfway full before adding the re-enforcement. Pack the concrete into all corners using your hands.
Place the re-enforcement in the mold. Make sure it is centered and flat so metal does not stick out of your finished piece. You'll also want to place it in the concrete when the mold is half filled to prevent shadowing from occurring.
Continue packing concrete into the mold until it is about level with the top. Then use a 2×4 to level off or screed the concrete. Move it back and forth in a saw like motion. Do this multiple times until the concrete is perfectly level. Fill in low spots as needed.
Vibrating the concrete will release many of the air bubbles. One method of doing so is to shake the table rapidly for a few minutes. I'd also recommend using a rubber mallet to tap the sides of the mold. The tapping action will remove additional air pockets. You could run an orbital sander around the perimeter as well and use the vibration in the tool to knock air bubbles out.
Use a trowel to smooth out the concrete. You could also use a float to help bring more of the concrete cream (portland cement) to the top.
Let the concrete cure for an hour or so before you start troweling. The time really varies depending on the temperature and humidity. You'll know the concrete is firm enough to do your first round of troweling when you can touch the concrete and no concrete stays on your finger. I typically trowel the concrete at this time.
Use a steel trowel to “hard trowel the concrete.” I wanted to have a lot of texture and trowel marks and so I simply troweled it the one time. If you want it to be really smooth you can do 2 to 4 rounds of troweling. Getting really good at hard troweling does take a lot of practice. The technique I used is much simpler because you only need to trowel once and we are not going for a super smooth top. I simply wanted a trowel texture.
Let the concrete cure for at least 48 hours. You can then remove the concrete from the mold. My buddy Dustin is removing the screws from the mold to release the sidewalls. They will pop off pretty easily. If they are a little tough to get off you can always use a chisel or flathead screwdriver to help out. Make sure to never pry against the concrete though. Pry against the wood.
Use 120 or 220 grit sandpaper to remove the rough edges from the table. I also lightly sanded the top surface using 220 grit sandpaper to smooth the table out a bit.
Find someone to help you remove the base of the mold. Put some padding on the ground (a couple towels will work) and slowly rotate the counter to a vertical position. The mold will pop off. Slowly lower the concrete back to the ground. Provide plenty of support by evenly dispersing the weight between you and the helper when lowering back to the ground. After lowering, sand any rough edges you have not gotten yet.
Mix portland cement with either water or a bonding adhesive to a putty like consistency.
Use an orbital sander to sand and smooth out the edges. It will smooth out the slurry you added.
The acid stain I used for this project is from Quikrete. I'd like to thank Chad from Quikrete for supplying all the acid staining products for this project. I used their English Red and Coffee etching stains. Quikrete stains can be found in select Lowe's and Home Depots across the country. However, many do not stock it and I couldn't find a link online. So, one other option is to order a brand from Home Depot online. Stains are available on Amazon as well. Local concrete supply and decorative concrete stores also usually carry acid/reactive stains.
Pour some water over the entire surface prior to staining. The entire surface should be damp but not have puddles. The water will help the stain disperse more evenly and be forgiving in case you get drip marks etc on the concrete.
Fill acid resistant plastic spray bottles with the stain. You may want to dilute the stain with water according to the manufacturers directions. I put english red stain in one bottle and a coffee colored stain in the other. It is a good idea to do this in a well ventilated area and to wear gloves and a respirator during the process. I was trying to run the cameras which is why I a was not wearing the protective gear temporarily. I'd also recommend placing a tarp under the concrete to protect your grass or driveway. I had a nice brown ring in my grass for the next few weeks because I did not use a tarp 🙂 Woops!!
Apply stain until you get the desired look you are going for. To highlight areas with a certain color simply spray more of a color. The acid stain reacts with the limestone in the concrete and slowly turns the color of the concrete top.
After applying the stain you'll want to let the stain set for 8 hours or more. This allows it to penetrate into the surface about an 1/8 of an inch. The photo below shows what the stain looked like after completely drying.
Fill a bucket with water and either baking soda or ammonia. Pour the neutralizing mixture on the concrete. This will stop all reactions from continuing.
We used an acrylic based concrete sealer from Quikrete to protect and enhance the colors of the acid stained concrete table. It goes on looking somewhat milky, but will dry clear and look great. Dustin applied 3 thin coats of the concrete sealer.
I've built a number of bases out of wood and or steel. Dustin and I built this base out of pine and then stained it using provincial colored stain from MinWax. He based the table base off one of Ana Whites coffee table plans. However, the table base is beefed up with 4×4's for the legs and is much larger. I have a video and tutorial showing how I made a similar coffee table using Ana's plans here.
There are a few different methods you can use to attach the concrete to your table. The concrete does weigh about 12 to 15 pounds per square foot so it is heavy and comparable in weight to granite. I do not like to permanently attach concrete tops in case you need to move the furniture. Having the ability to easily remove the top and handle the base and top separately is convenient.
You could use construction adhesive to secure the top to the base, but it is a more permanent option and is hard to remove. Silicon will keep the concrete in place and is simple to pull up to remove. However, it will all have to be scraped off if you remove the top and then decide to re-attach it.
I like to attach wood blocks to the underside. I attach the blocks using construction adhesive.
Next, place the blocks inside the perimeter of the base. The photo below is of a metal base I made, but the same block process can be used on a wood base as well. The blocks will prevent the concrete from sliding around. I commonly rest my legs on the table when relaxing or watching tv. With the blocks in place the concrete will not move around. The blocks also allow the top to be removed easily for moving the furniture.
Thanks so much for checking out this tutorial. I hope it inspires you to build your own concrete table! If you are interested in learning about the reverse cast technique please check out my other concrete table tutorial. I also have a video and tutorial showing how to embed a metal logo in concrete which can be found here.
In a future post I will talk about other finishing methods. Below is a photo of what a table looks like if you grind it using a wet polisher and exposing the aggregate (rocks/sand). It can be a neat effect as well, but requires a special polisher found here.