Concrete slabs provide an ideal base for installing a fire pit; they are stable, fireproof and typically already level. If you have a concrete patio, or have laid a concrete slab specifically for the fire pit, you will be creating an outdoor feature that can provide both warmth, light and if occasion calls for it, food. Fire pits can easily be turned into a makeshift barbecue grill by simply putting a grill plate over the opening.
Draw the dimensions of the fire pit onto the concrete slab, using chalk. Most fire pits are round, but you can make a square, rectangular, octagon or any other shape you want. If you're using a fire pit insert, use the size of the insert as a guide to the pit dimensions.
Dry-lay the bricks around the chalked-in lines. Build up the walls of the bricks to around 2 feet high, staggering the joints to add strength.
Mix the surface bonding cement according to the manufacturer's directions. Apply the cement to the entire brick structure. Use the trowel to smooth on the cement, creating a layer all over around ½ inch thick. Extend the cement out at the base around 5 inches, then graduate it to the level of the concrete slab. Allow the pit to cure for at least three days.