Build The Ultimate Outdoor Kitchen Grill Island

Let’s build the ultimate outdoor kitchen grill island. One that can stand up to the elements, is low maintenance and looks amazing year after year. 

In this series you will learn how to build a cinder block bbq grill island. Finished with field stone and topped off with a concrete bar and counter top. If this sounds good to you… let’s get started.

This project is the perfect addition to any backyard whether you have a water feature (start your pond project her) or not. Just like your indoor kitchen is the heart of your home, this will quickly become your new favorite gathering place.

Grill island and pond with waterfall

Tools required

  • Shovel
  • Grout bag
  • Pointing tool
  • Hamer
  • Level
  • Paint brush
  • Wheel Barrow
  • String line
  • Hand tamper
  • Rake


Where To Begin

It’s important to select the right location. You don’t want to travel too far back and forth from your kitchen to your grill. It is also important to orient the entire project in such a way that it creates an inviting area for people to gather. 

If you have a water feature or garden be sure to layout your design so they can be enjoyed by everyone.

planting around a new backyard pond to make it look natural

This is where I may have made a “mistake” in a selfish way. When I did this project, it is oriented so the one doing the cooking (ME) gets the best view of the pond and waterfall. People at the bar only get to have a conversation with the grill master! But hey, what more could you want… I’m awesome!

When you plan out your project, keep these things in mind. It’s stuff like that you don’t think of until after, when it’s too late.

For our project we used a simple “L” formation. Don’t let what we do limit you. Go as big or small as you need to. You are only limited by your imagination. 

Using the “L” shape gives me an option to add on to it in the future if I want more counter space or bigger area for seating and entertaining.

Outline Your Project

Once you have decided on the location and the shape of your next masterpiece, use a can of spray paint to outline where the foundation will be. 

When you do your layout, you will need to dig out 8 inches wider than you plan the island to be. This is so the entire island is supported once you add field stone on the cinder blocks. 

For this project, my dimensions for my foundation were 16″ wide everywhere, which allows 4″ on either side of the 8″ wide blocks. The other 3 lengths being 32″ X 80″ X 88″

When doing your layout keep in mind the dimensions of the cinder blocks. The ones used were 8” x 8” x 16”. Make it easy on yourself and create a form that will accommodate these dimensions so you don’t have to cut any of the blocks.

Required Supplies

  • Cinder Block
  • Mortar Mix
  • 2 x 4's
  • Field Stone or tile
  • Conduit (optional)
  • Screws
  • Stakes
  • Gravel
  • Concrete Mix

Nothing Worthwhile Is Easy

Hopefully your hands and back have healed some since your last project. Now it’s time to break out you two best friends… your shovel, and your will and start digging again!  

Remember it is important to know there are no underground utilities before you dig.  Always check here before you dig.

You want to remove dirt until you are 12 inches from where the top of your foundation will be. In order to achieve this, you will need wooden stakes, hammer, level, and a string line. 

After you paint out your outline take one stake at the highest point of your site and pound It Into the ground. The top of this stake will be the top of your foundation.

Now pound another stake in around the perimeter. Now place your level on the first stake. Pound the second stake in the ground until the second stake is level with the first one. 

If your stakes are further apart than your level is long, rest your level on the straightest 2 X 4 you can find and use that span the gap.

Go around the entire perimeter and setting a stake every 4 feet or so. This will ensure that you reach the proper depth. Now dig down until you are 12 below the top of your stakes. 

Do not disturb the ground deeper than you plan on digging. Leaving this ground undisturbed will help stop your foundation from settling.

Using a hand tamper, compact the dirt on the bottom of your trench. If you plan on having electricity in your island, now would be the time to put conduit in place. 

Thinking ahead when doing a project like this will really pay off. Even if you don’t put electric out there immediately, at least you will have set yourself up to do it in the future.

Now That You’re Down…

Now fill the trench back up with 2” crusher run (driveway stone). As you fill in the area, level it roughly with a rake and use your tamper to compact it as you go. 

Fill the trench until the stone is 6 inches below the top of your stakes. Use the hand tamper to make sure everything is compacted well. The stone is going to be a solid base that allows proper drainage below the project.

Taking Form

Time to make your forms. A form is the shape you want the concrete to “form” into. Think of it like a negative.

The space inside the form you build will be your foundation. I used 2 x 4’s to build my form. The wood gave the foundation a clean edge above ground, and the ground acted as the lower part of the form.

Use screws when you make your form. This way you can take it apart easily after it has cured. All screws must be screwed in on the outside of your form. Once you add the concrete you will not have access to the screws beneath the concrete.

Here is an example of the form I used:

grill island concrete form

Once you have your form built, put it in place. Now pound stakes around the outside of your form. The top of your form will be the top of the foundation for your grill island. Starting next to a stake, get your form to the desired height. 

Screw your form to the stake to hold it in place. Using a level, go around the entire perimeter to make sure your form is level. once the top of the form is where you want it, screw your stake to the form to hold it all in place.

When you are done, check level from side to side as well as in line. Take your time, it’s important to get this right. The success of this project is resting on your strong, level foundation.

For this project I used bags of concrete mix. If your project is larger than this you may consider renting a cement mixer to save your back!

Of course I did it the “old school” way, using a shovel and wheelbarrow. 

We used quikrete ready concrete mix. Here is a link to their chart to calculate how many bags of concrete you will need. If you use something different check with the concrete manufacturer for estimated quantities. Always be sure to buy a couple extra just in case.

Before you begin mixing concrete, you will want to reinforce the concrete with rigid wire mesh. Cut it so that it covers the trench. 

It doesn't have to go all the way to the edges. Using pieces of cut off wire as legs, prop the mesh above the driveway stone so it is suspended above it.

Mix It Up

It’s important to mix your concrete thoroughly so it will cure properly and not have weak spots. Begin to pour the mixed concrete at one end of the trench and fill it to the top of your forms.

As you go you will need a 2 x 4 and a helping hand. Place the 2x4 on the form, spanning the freshly poured concrete and move it side to side in a sawing motion at the same time pulling it across the newly poured concrete. 

If there are any voids, add more concrete and repeat the process. It’s OK if some spills over the edge. Making a mess is all part of the fun!

Keep adding concrete and leveling off the top until the entire foundation is poured. 

Allow the concrete to set up, then using a concrete float, go and smooth out the top. This step isn’t all that necessary for this particular project because mostly all of it will be covered by the island.

Finishing concrete is an acquired skill. One in which I wish I had. For this project your finished concrete will be hidden so it’s good practice and no one will be the wiser. 

Give it a shot and let out your inner mason! Full disclosure, prior to this project I had very minimal experience with any type of masonry. If I could do it … so can you!

Let It Cure

Once you are satisfied with the finish on your concrete foundation, walk away and let it cure. I would wait a week before building on your new concrete. Check the manufacturers recommendations before going any further.

Lay The Course

Cinder blocks are the bones of the project, and when we are finished it’s going to be something custom, and high class. This thing will stand the test of time.

first course cinder block grill island

With your foundation in place, it’s time to lay your first course of cinder blocks. It’s a good idea to lay out your blocks first to be sure everything would fit properly before you start mixing any mortar. 

Before you begin place a stake in the ground where you want the edge of your blocks to be. Place another stake at the other end. Use a stringline between the two stakes to guide you as you lay your first course. The first course is the most important. The string line will keep your blocks from drifting off. Remove your dry fit blocks…. It’s time to get messy!

how to lay cinder blocks

Stay The Course

I found this whole process a bit tricky. Not to be discouraging but it does take a bit of practice to lay down just the right amount of mortar for your cinder blocks to rest in. 

You can watch video after video, but until you actually try it, you will never know how difficult it truly is.

All you need for this part of the project is patience, cinder blocks, mortar, and a good trowel.

Since I wasn’t experienced, it took me a lot longer, and I wasted a lot of mortar! The only way to learn is to try.

Only mix up as much mortar as you can use in 15 to 20 minutes. This will help to cut down on waste. You will get the hang of it once you get started.

Scoop up some mortar with your trowel and make 2 strips about 1” wide and about 1” high for either side of your block to sit on. Place the same size amount on the ends as well.

Grab your block and place it evenly on the fresh bed of mortar. Be sure not to push down on it too much, as this will squish the mortar out. Use your level and the handle of your trowel to tap the block until it is level.

One down, all the rest to go! Place a bed of mortar on the end of the block you just laid so it will connect to the next block you will lay, and another bed of mortar for it to set in. Repeat this process until you’ve laid the first course.

Laying The Next Course of Cinder Blocks

Starting on the second course, be sure to stagger your seams. If you don’t, it will create weak points in the wall and you will have issues down the road. Just keep everything straight and level as you go.

The average height of a counter top is about 4 eight-inch cinder blocks high (32 inches). If all you want is a counter top, stop there. 

For the bar seating area I went one more course. This gave a good backdrop for my grill, and also elevated the people sitting there so we could strike up conversation as the food was being prepared.

building up cinder blocks for grill island

After you’ve laid your final course, let it cure for a few days. The length of time depends on the temperature and the humidity.

Decisions, Decisions, Decisions

Your “bones” are in place. It’s time to make your decision on how you want to finish the project. Stone veneer, real stone, or even tile. The possibilities are seemingly endless.

Placing fieldstone on a grill island

I am fortunate enough to have an extremely generous neighbor who happens to be a farmer. He allowed me to take all the rock I wanted from his field down the road. 

When I say that my island is made of fieldstone, it truly is made from stone right out of the field down the road. Thanks again Big John.

Once you’ve made your decision, it’s time to get back to work. If you use tile, be sure to dry fit and plan it out before you start. You don’t want to wind up with a sliver of a tile at one end. 

flagstone grill island

In my case all the shapes were random. It took a lot of trial and error to get the stones to fit just right. If you use random shaped rocks, take your time. Make sure you are happy with the way it looks before the mortar cures. 

This thing is built like a tank and you will be looking at it for many years, so be sure you are content.

As you can see from the pictures, some rocks were quite heavy and required bracing until the mortar set. If you are using some sort of manufactured stone veneer it will probably go much quicker as they are manufactured to fit together.

holding up heavy field stone in cinder block grill island

Begin The Giant Puzzle

This took me a month to complete. Probably because I’m very picky and had to use just the right stone, in just the right place. Placing the stones just right was like doing a jigsaw puzzle.

Putting on the last stone was the best feeling! You may even want someone there to give you a drum roll when you do it (I did)!

I also used a couple of 4 x 4’s to go across the two openings you see in the picture. This is so I can easily attach doors, by screwing hinges into the wood in the future. 

fitting in the field stone on bbq grill island

I covered the wood with cement backer board, the material you would use in a shower or bathroom. I then covered it with the field stone. I used a grinder with a diamond blade to cut any rocks that were sticking up past the cinder blocks. You need a flat surface for your countertop to rest.

building a grill island outside

Inside the island I installed two wire shelves braced up on bricks. This is a great place to store all your grilling supplies and keep them out of the weather right at the point of use!

How To Grout Field Stone

Admire your work for a bit and allow everything to cure. Then it’s time to fill in the gaps between the rocks with mortar. This will bind them everything together. 

Grouting field stone in grill island

Even the heaviest of rocks will be locked in place. This is crucial during the freezing and thawing cycles of the seasons, at least where I live.

Use a grout bag (Amazon link) for this procedure. A grout bag looks like the thing used in the bakery to frost cakes. It works fairly well.

grouting field stone grill island

Mix up your mortar so it’s more runny and not as stiff as normal so you can squeeze it through the grout bag hole.

Starting at the bottom, squeeze the mortar into the gaps. Be sure to use rubber gloves as the chemicals in the mortar will eat your skin away after too much exposure.

The easiest technique I found was to squeeze in the mortar, then smooth it out with my finger (with rubber gloves on). I know there is a tool for this called a pointing tool (link to Amazon) but I felt I had more control doing it this way. 

Keep a sponge handy to remove any excess mortar that may have gotten onto the rocks before it cures. It’s a lot easier to remove the excess now, rather than after it dries. 

Do one side at a time. Once you are finished with one, go back to where you started and using a paintbrush smooth out all the cracks. The paintbrush leaves a nice texture as well and makes it all look uniform.

Conclusion

By now, you know how to start your outdoor kitchen grill island project the right way. We aren’t finished yet. Read the next section where we will be adding a polished concrete countertop. Oh yeah, and don’t forget the lights. 

custom grill island

~Jeff

About the Author Jeff

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