How to Build a BBQ Grill Base

Spread a 3/8- to 1-inch-thick layer of mortar on the concrete in a square formation matching the desired dimensions of the base. Make the run of mortar as wide as the blocks. Push the mortar on the inside to the edges so the perimeter of the mortar run is higher than the center.

Place the first block at one corner of the mortar square. Gently tap the top of the block with a rubber mallet to settle it into the mortar. Use a level to check and adjust the block for evenness. Scrape off the extra mortar that seeps out from under the block, using a trowel.

Apply mortar to one end of the block and tap in the second block, using the level to adjust for evenness. Keep laying blocks until the first course is completed. Check the corners with a square to ensure 90-degree angles.

Lay mortar onto the tops of the first course and set in blocks for the second course in the same manner. Stagger the blocks so the joints alternate. Continue adding courses until the desired height of the base is reached.

Wait until the mortar just starts to stiffen, then smooth down the mortar joints. Create smooth, concave joints by running the end of a jointer tool along the mortar lines.

Spread mortar on top of the last course of blocks. Set on a real or cultured stone slab. Place a level on top and tap the slab into place. Allow the mortar to stiffen and smooth down the extra that seeped out of the joint where the last course of blocks meet the slab.