How to Construct a Grill Island From Concrete Blocks

Build your block island up around the grill. Place the grill in the area where you want it and outline its space on the floor of the deck or patio with a pencil. Use these pencil lines, as a reference, when building the block structures on either side of the grill itself. Remove the grill to leave the empty space behind so you don’t get concrete on the grill.

Mount the first row of blocks onto the patio or deck planking with brackets. Screw directly into the deck planking with a drill and the self-tapping screws provided with the brackets. Use the pencil line as a guide and install the first horizontal row according to the dimensions of your island. Leave roughly 1/4-inch to 3/8-inch between each block to serve as a joint.

Mix up some concrete in a wheelbarrow with a shovel. Add just enough water to create a thick, creamy mixture. Don’t mix the whole bag unless you are comfortable working quickly as you only have an hour or so before the concrete will harden beyond a workable point. Use a mason's trowel to fill the gaps between the first row of blocks with mortar and apply at least 3/4-inch of mud on top of the first row of blocks.

Place the second row of blocks on top of the first row. Stagger this second row so that the vertical joints of the first row line up with the center of the blocks on the second row. Place them loosely on top of the mud and apply about a 1/2-inch of mud in between each block. Tap them into place against each other with a rubber mallet. Place a level on top of the second row and tap the blocks gently down into the concrete to level it against the first row.

Repeat the mud process on top of the second row but mirror the joints of the first row. Alternate accordingly as you work your way up the island until you achieve your finished height. Check for level at each row until you are finished. Cut the excess concrete away from the face of the block wall with the trowel to leave a flat, smooth finish.

Make any necessary cuts to end blocks with a masonry wet saw. Mark the pieces with a tape measure and pencil. Place a block on the saw's tray. Turn on the saw and push the tray with the block on it into the blade. Push it through the blade to cut the piece.