Wood and concrete coffee table

ash wood coffee table with concrete legs

I have just built this wood and concrete coffee table.

I started to like the idea of combining materials that are not usually used together. I saw a few pieces of furniture in combinations of concrete and wood that I liked a lot. I have decided to make this wood and concrete coffee table.

I then sketched a coffee table to build it out of these two materials. The mix between the warmth of the wood and the harsh concrete would give it a very special look. Besides the look, the large weight (over 50 kg) of the legs would make this coffee table ideal for people with small children or pets, since it would be very difficult to topple.

First of all, I built an ash wood panel for the tabletop. I won’t insist with the process of gluing up the panel. An easier way of building a panel as flat as possible is using a 4-way clamping system. We designed and built such clamps. You can download the free plans to build your own 4-way clamps to glue large panels with easy. There is also a video where you will see how this clamping system works.

We decided to secure the wooden top to the concrete legs with metal brackets. In the same time, we didn’t want them to be visible. So, I found a simple solution: I glued up a border on all the edges of the panel. This way I made the brackets less visible.

We built the panel a little bit longer then the final size. We wanted to build the end grain borders by cutting the ends of the panel and gluing it up after turning them on the other side.

So, I cut one end of the panel at 90 degrees angle. I had a 3 cm wide strip. I made the same cut at the other end of the panel. I used each wooden strip at the panel end where it has been cut from.

when building the wooden top of the concrete coffee table, we turned the cut strip so the end grain pattern to match perfectly — By turning the strip upside down the end grain pattern matched perfectly

They had to be glued under the end, upside down, to match the end grain of of the panel. This way the and grain of the coffee table top should be continuous, creating a very nice mirror effect.

we glued the border of the ash wood top of the coffee table using polyurethane adhesive — Gluing the border using polyurethane adhesive

After the glue has dried, I glued two ash wood planks on the long edges of the panel.

When the whole panel was bordered, I cut the slots for the concrete legs.

I marked the two slots I had to cut for the concrete legs of the coffee table — Marking the slots that had to be cut

First I made the long cuts with the circular saw using a straight plank clamped on to the panel as a guide.

we cutout the ash wood table top using the circular saw — Cutting the slots in the ash panel using the circular saw

I finished the cuts using the jig saw.

The jig saw was used to finish the cuts — Finishing the cuts with the jig saw

I also cut the shorter sides of the slots using the jig saw.

we made two cutouts in order to easy install the ash wood top of the coffee table — The slots in the ash table top are cut

For the molds (needed to build the concrete legs), I purchased from a local diy store some 4 cm thick kitchen countertops scraps and some white laminated panels. Before using the counter top pieces as molds for pouring the concrete I sealed them. I first filled the holes with wood putty.

I filled all the holes of the molds with putty to protect them against moisture — The holes filled with wood putty

I sanded the excess and then I painted everything with black flexible paint.

we used flexible paint to seal the edges of the molds — The edges were sealed using flexible paint

I applied the thick paint on the edges of the molds, using a paintbrush — The thick paint cannot be sprayed and has to be applied with a paintbrush

we assembled the mold for pouring the concrete legs — Assembling the mold for the concrete legs

In order to secure the metal brackets, I milled slots in the molds. I placed them so that the table top would sit flush to the ends of the concrete legs.

I drilled two slots to fix the metal brackets into the concrete legs — I milled two slots for the metal brackets

I used some scrap metal pieces to reinforce the concrete. Even though I was sure that the concrete block would be hard enough, I preferred to reinforce it.

I also built the metal reinforcement of the concrete legs — The metal reinforcement of the concrete legs and the metal brackets

So that, the metal brackets would be better secured to the concrete legs of the coffee table.

we prepared the molds for the pour, so we can build the concrete legs for the coffee table — The molds prepared for the pour

I mixed the concrete using the mixer that I have in my yard. It helped me to be sure that the concrete is thoroughly mixed.

I mixed the ingredients for the concrete with a mixer — I mixed the concrete with a mixer

I then poured the concrete into the molds, making sure the reinforcements wouldn’t not move from their places. I compacted the concrete using a hammer. I hit the mold walls with the hummer trying to compact the concrete as well as possible.

we filled the molds with concrete in order to build the two legs of the wood concrete coffee table — The concrete was poured into the molds

I removed the mold of the first leg three days after the pour, so I chipped it a little because I had to force it to remove the panel with the metal brackets going through it. For the second leg I waited 28 days until I removed the mold. The second one turned out great.

Once both molds were removed, I could finally check if all my calculations were good and if the ash wood top of the coffee table fits to the legs. I had to make minor adjustments. I did them using the jigsaw (to enlarge the cutouts of the table top) and the angle grinder (to sand the concrete legs) so that everything to fit perfectly.

I used the angle grinder to make some adjustments — Making adjustments using the angle grinder

The top ends of the concrete legs were too rough. I couldn’t let them that way. I wanted to sand the concrete. I also didn’t want to invest almost 100 USD to buy a special diamond grinding concrete disc. So I bought a tool for the angle grinder, designed to sand stone, that was a lot cheaper. Since it was designed to polish stones and the concrete is made out of stones, sand and cement, it worked.

sanding the concrete with a special disc for concrete using the angle grinder — Sanding the concrete with the angle grinder

I’m sure it took me a lot longer than with a diamond grinding concrete disc, but I did my job.

the concrete legs of the coffee table exceed the level of the ash wood top — The legs protrude a little through the ash wood table

While grinding, I noticed that applying water makes the concrete much easier to flatten. So I kept on applying water from time to time, using a paintbrush.

we applied water on the top of the concrete legs to sand them easily — Applying water helps ease sanding the concrete

Because I was almost sure that the angle grinder might slip on the wooden table top, I put adhesive tape on the wooden panel, right next to the concrete legs. The tape did it’s job by protecting the wood 3 – 4 times when the angle grinder slipped towards the wood.

painter tape was used to protect the ash table top panel — I protected the wood panel with painter tape

When I was satisfied with the look of the coffee table, I started to finish all the pieces of the wood and concrete coffee table.

Using a paintbrush, I applied a special resin to the concrete legs.

I applied to the concrete legs of the coffee table the sealing resin using a paintbrush — The sealing resin is applied with a paintbrush

After the first coat was dry, I applied the second one, to make sure that all the concrete pores are sealed.

we finished the concrete legs of the coffee table by applying sealant for concrete — The legs finished with sealant for concrete

I followed the usual steps to finish the wooden table top: I stained it using a sponge. After the stain has dried, I noticed that the ash wood table top looks very similar to a wood that is very expensive around here: the zebrano.

the way the end grain edge of the table top looks like — The end grain edge of the ash coffee table

I then applied the water based primer and two coats of matte water based varnish. The matte varnish protects the wood but also keeps the look much closer to the natural wood.

the way the stained ash wood top of the coffee table looks — The ash wood panel looks beautiful

When I assembled the parts, I noticed that the resin gave the concrete a beautiful shine, which didn’t match at all with the matte varnish applied to the table top. So I sanded lightly the top ends of the legs and I applied a coat of matte varnish to them, too. The difference was huge and I am very glad I did that.

Since I had to move the concrete legs around a lot ( I polished them outside, for obvious reasons). I was curious to weight them: around 25 kg each. So, the whole table have around 55 kg. There was absolutely no chance that the coffee table might be moved by a child or a dog.

When I placed the coffee table in front of the couch, I realized that this small coffee table changed the look of the entire room.