How to Make Concrete Countertops Amazingly

As a home improvement project, learning how to make concrete countertops is a big one. If you've never mixed and poured concrete before, then you should probably not try this.

If you do have some concrete mixing experience, DIY skills and the tools, lumber, and know-how to create concrete slabs, then you might consider it. But you should treat it as at least a two person job.

Working with concrete can be backbreaking work, and the creation of anything made of concrete takes time, not only to build it, but also to let it cure properly.

It is probably wise for your first DIY concrete countertop to be small, such as a small outdoor "island" for a barbecue area, and it should be simple and require minimal finishing and coloring.

There are many reasons why concrete kitchen countertops are gaining popularity. Concrete countertops can incorporate kitchen features like back splashes, butcher blocks, and sinks, and they can be created in a huge range of colors, designs, and textures.

Concrete countertops are made with fiber reinforcement, acrylic, and silica fume pozzolan. Pozzolan is a material which is combined with calcium hydroxide to create a substance with cement-like qualities.

Silica fume is a byproduct of silicon metal production and it happens to make a really good pozzolan. Silica fume pozzolan adds strength and durability to concrete.

Professional makers of concrete countertops choose to either pre-cast the countertop in a shop, or build it on-site.

There are advantages and disadvantages to each choice.

Built in a shop, conditions are more controlled, special casting tables are available, and it can be monitored during the curing process.

On the other hand, concrete countertops built on-site can be more easily customized to take care of any last minute minor changes like curved corners.

Another advantage of building countertops in place is that very long countertops can be made without seams, and there are cases where a shop-built countertop might not fit through a doorway.

Tools and Materials Required:

A number of tools and supplies are needed for building a concrete countertop. Here is a partial list:countertop molds
casting table
concrete countertop mix
concrete mixer
reinforcing material
pigments
knockouts for sinks and other integrated features

To understand how to make concrete countertops well requires you to have a thorough understanding of properly mixing and reinforcing concrete to prevent cracks from developing.

A good understanding of countertop sealers is important too.

Many concrete countertop artisans mix their own custom sealer combinations to get the best results. This is a skill they've likely learned the hard way, by trial and error.

Some concrete countertop makers use a polisher to grind the cement to a smooth surface. Skilled countertop makers may, for example, grind off the "skin" of the concrete surface with a series of progressively finer diamond polishing stones to maximize durability and beauty.

After curing and polishing, countertops are sealed. Different people use different techniques for this.

Epoxy sealers have a good reputation, but take a week to apply properly.

Clearly there is a lot to learn when it comes to building custom concrete countertops, and fortunately there are classes offered in the U.S. and Canada where you can learn more about the process of making concrete countertops.

It would definitely be a good idea to do tons of research first step before tackling this project... I can only write so much and personally do not like to star in videos, but they are available and quite helpful for a project with so many faucets (oops, i mean facets, haha).

Countertop Planning

The first step when creating a DIY concrete countertop is planning.

You do not want to finish a countertop and then have to maneuver it around tight corners or over long distance.

Each foot of countertop space can weigh 20 lbs depending on thickness.

Your workspace must be well-ventilated and there must be plenty of room.

A final very important preparatory step is to make sure that the cabinetry under the countertop is going support the weight of a concrete countertop.

Shoot me an email if you could use some help with figuring out if your cabinets can support your counter.

Making the Template

Acquire a sheet of wood veneer, sized depending upon how big the countertop will be. You'll also need a glue gun and glue sticks. Onto the sheet of wood veneer, trace the base of the countertop.

It is important to note that you're tracing the base of the countertop - in other words the dimensions of the cabinetry that the counter top will rest upon.

Overhangs for a typical countertop are 0.5 to 0.75 inches.

Next, you'll mark the template with control joints.

Let's say your concrete counter is 10' in length. The distance between the control joints should never exceed four feet.

If we divide the 10-foot section into thirds, and place the control joints at 1/3 of the length and 2/3 of the length, we'll place them at 40" (3'4") and 80" (6'8").

These joints are less than four feet apart, so they should work fine.

Obviously, the longer the countertop, the more control joints there will be.

Control joints are a way for you to influence where concrete cracks. Control joints allow for movement due to temperature changes and shrinkage as the concrete dries.

In general, space the control joints in feet no more than two to three times the slab thickness in inches.

If your slab is 3 inches thick, control joints should be placed 6 to 8 feet apart.

Control joints are cut to 25% of the depth of the slab. So for a 3 inch thick slab, control joints should be 0.75 inches deep.

Precisely when you cut these control joints has to do with the curing of the concrete and the weather and other atmospheric conditions.

Building the Frame

The next step is to build the frame for your DIY concrete countertop using poplar or pine 1 x 3s held together with screws.

Use a 0.75 inch medium density fiber board for the bottom of the frame. Attach this with deck screws too. Seal inside edges and corners with caulk to give the countertop slightly rounded edges.

Coat the inside of the frame with paste wax. Make a rebar grid with intersections approximately every 4 inches and secure the intersections with plastic zip ties.

Suspend the grid by placing two pieces of 1 x 2s or scrap across the frame and suspend the rebar halfway up from the bottom of the frame from them using wire.

Pouring the Concrete

Finally, it's showtime.

This is when you mix, pour, and cure your DIY concrete countertop properly.

There are numerous benefits to constructing a countertop made of concrete: It is an inexpensive way to create a truly unique

and creative aspect of your home. Additionally, the counter will be maintenance is low and its durability will be much higher than that of a more traditional laminate countertop.

To maximize your odds of creating an eye-catching concrete countertop, I recommend using Quickcrete Countertop Mix

The Quickcrete countertop mix that I recommend takes alot of the guesswork out of mix preparation. If you follow the instructions provided on the bag, great results will likely follow.

Although a a concrete mix formulated specifically for counter tops will alleviate much of the need to vibrate the concrete,

you will still need to vibrate the counter top mix to get rid of air voids in order to create the smooth and "slick" finish

that will catch your guest's eyes when they come over for dinner.

It contains a superplasticizer that will create a flowable mix- without a high w/c ratio.

When your counter top mix is ready, get at least two other people to help you lift it into place for finishing.

source:  Meet Mr Concrete - Your DIY Concrete Mentor