Tutorial: Concrete Countertops

Concrete?  People questioned what we were doing – like a sidewalk on your  counter?  It was funny!  Yes – concrete countertops; but no, not a sidewalk – same material, different look/finish. Our concrete adventure in May took us 8 days and deprived us of some tasty home cooked food.  It was so much fun – so I highly recommend doing your own concrete countertops – the experience is rewarding, exciting, and truthfully, money saving .  Just be willing to try and you’ll be rewarded.

After

The after is so different from the before – we changed the sink, added a subway tile backsplash, and removed the wall that was behind the previous fridge location.  We also installed industrial lighting, added a new open concept cabinet, with of course, a new countertop!  We created a detailed schedule and budget, what we didn’t account for was making 15 trips to home depot over 12 days!  One day we hit up the Home Depot 4 times…and we live in the country, so that was about 2.5 hours spent resting in the car.  Believe me, it was a nice break.

The before was okay.  It was liveable, for sure, yet ugly.  The kitchen was originally painted a light yellow and had hunter green countertops.  Sir James Dunn, and old high school in my home town, had school colours that were yellow and green – I’ve never been a fan.  All the trim was mis-match and the fridge was right sung against the stove.  Certainly, not ideal for cooking and baking.  I like having room on either side of the stove to spread out, if you will.  Like when I was a student, or a teacher, papers spread out all over the table…none of this ‘cubical’ type work environment.  The idea came to us to move the fridge when we first viewed the house.  The bedroom off the kitchen had 2 closets – fairly decent size, too.  So, backing the fridge into one just seemed logical to both of us.  Let me be clear in the sense that we have never done anything like this before, yet by putting tips together from various sites, asking the people in the know at Home Depot, and by having a little faith, we got the job done, and done well.

Before

Materials you’ll need

•  Concrete (kind depends on the finish you want)
•  Cement Mixer (rental)
• Water (with a hose)
•  Melamine (wood for molds)
•  Table Saw
•  Drill
•  Screws
•  Straight Edged Towel
•  Translucent Cocking
•  Woven Wire (thicker than chicken wire)
•  Adhesive
•  Shims
•  Level
•  Orbital Sander
•  Sand Paper (80-200 grit)
•  Concrete Sealer  (roller for application)
•  Food Grade Wax (rag for application)

——————————————————————————————————————————————————————-

First Step – take off the old countertops.

We weren’t changing our cabinets, so it was important to be careful and not damage them when removing the old counters.  Hopefully we’ll be refinishing them soon, but we certainly didn’t want to add another project to this kitchen reno!

Step Two – measure and prep.

In order to give the countertops the best chance at being level – sand down the top of the cabinet frames.  Also, this is a great time to paint, or refinish the inside of the cabinets! Measure for your future concrete countertops correctly and don’t be afraid to double check (also, account for the thickness of the Melamine you got for when you assemble the molds – kind of like a seam allowance for you sewers!).  For our overhang we had a hard time deciding whether 2 inches or 4 inches was better.  In addition, we moved the fridge into the wall and build a new cabinet where the old fridge used to be – the issue?  We wanted a large enough overhang for stools on the other side, yet had nothing to compare it to (no countertop had existed there, ever).  What you want:  a design that will work for you, be functional for you, and be beautiful to you!

Third Step – make the molds.

Melamine is a finished particleboard – Home Depot has it in stock, it’s inexpensive, and it’s easy to work with.  Use the table saw to make all the cuts (a sharp blade will minimize chipping of the melamine finish).  Once you have everything cut, assemble away!  A few tips on assembling your molds: pre-drill screw holes to prevent popping a screw and ruining your concrete countertop; put the edges of the mold along the side of the base (not on top of the base) – this will help to strengthen the mold and give the top a more finished look; put the molds on a level surface before you pore the concrete.

Step Four – mixing the concrete.

This is the core of the process – too runny and it takes forever to dry and is weak – too rocky, it dries fast, is heavy to move, and creates a rough, uneven surface – a perfect balance is your goal.  Read the bag – we added more water than it first called for, yet not as much as the max limit for the kind we purchased.  Remember the ratio!  Our ratio was 2 bags to 13 litres of water – this depends on the time of year, humidity, elevation, and all that jazz.  In the end, you want all countertops to have the same ratio.  Don’t laugh, but we purchased 8 bag of concrete and had to run to Home Depot at 7 am one morning because we had run out the night before……we used a total of 14 bags!

Fifth Step – pouring the concrete.

Pour and fill about ½ the mold – then bury in the woven wire and top it off with more concrete.  Use the straight edged trowel to level it off (I levelled it off with my hands – wear gloves – then Bryce went over it with the trowel to make it perfect).  Now, with no sandpaper, use the orbital sander and sand around the outside of each mold – this will help the concrete settle into the mold and cause the air bubbles to rise to the top – creating an overall stronger, smoother countertop.  Pour then sand the edges, pour the next and sand the edges – don’t let the mold sit full for too long without getting rid of the air bubbles.

Sixth Step – wait and wait, then take off the molds.

You have to let the concrete dry.  Our smallest piece was ready in 5 days, yet our largest (more than 8 bags of concrete) took more than a week to dry.

Carefully unscrew the edges off the molds (another reason it’s the best idea to attach them to the side of the base, so it has support once the edges are off).  Now slide the countertop off, flip it, and put it in its place on top of the cabinets.  Each countertop – we did 4 – took creativity in order to get it into place.  Be sure you have lots of help, since they’re heavy!

Step Seven – secure and level.

Tilt each countertop up and lay down the adhesive.  Use the same method as you would if you were gluing wood together – don’t overlap the adhesive, this will create air pockets resulting in an unlevel surface.  Apply in an ‘S’ pattern.  Use shims to help level the counter – they will also add strength.

Eighth Step – fill and sand.

Use concrete filler (it comes in different colours, or you can dye it).  Fill in the larger holes.  Let it dry for a day – during that day, block off any part of your house with plastic sheets, since the concrete dust is yucky and you don’t really want it everywhere throughout your house (we made a mistake and didn’t do this – I was cleaning walls for weeks).  Now sand the whole countertop – use the rough grit first, working your way up to the finest grit.  Stop when you have the finish/smoothness you like.  You can go very high and get it to look almost like glass, but that’s not the look we were going for.

Step Nine – seal and polish/wax.

Be sure to seal your concrete countertop so it doesn’t absorb water and spills, which will cause weakness and cracking.  We applied ours with small sponge rollers and we were sure to seal the sides, too.  Also, seal as many times as it takes (like 14 times!) to have a drop of water completely sit on top of the counter – no absorption.  Now apply a food grade wax – as odd as this may seem, we used Carnauba Wax, which is made for cars!  Strangely enough, however, it’s also food safe!  If you’re looking for that high gloss, don’t apply the wax and use an epoxy resin instead – basically it’s a plastic that will bond to the concrete and create a high gloss.  We didn’t do this, mainly because we wanted a more industrial feel to our kitchen.

Tenth Step – cook and enjoy!!

Live, cook, and play in your new kitchen!