Laying pavers on a concrete base is a challenging yet potentially rewarding project. Using an existing concrete base helps ensure a solid, stable foundation that can last longer than a patio built using the dry installation method, which uses sand and crushed gravel instead of mortar. The cost savings associated with laying pavers yourself can be substantial. Expect to spend at least a weekend working on the project.
Prepare a solution of trisodium phosphate and water in a bucket. The container in which the trisodium phosphate is packaged will provide mixing instructions for various uses of the product. Follow those instructions.
Using a wire brush and the solution of trisodium phosphate, scrub clean the surface of the concrete and the face of each of the pavers that will be used.
Measure the length and width of the concrete base. Construct a temporary base using the two-by-fours, making cuts as necessary so the boards fit along the outside border of the concrete slab. Set each piece of two-by-four flat along the border and attach them together using a hammer and nails.
Mix the mortar according to the package instructions. Start in any corner you choose and lay a 1-inch thick layer of mortar, enough for one row of pavers. Use a trowel to spread the mortar into a smooth, even layer.
Set the pavers one at a time on the mortar. Put 1/4-inch spacers between each of the pavers after you lay them down.
Repeat the process above. Lay down another row of mortar, spread the mortar with a trowel, lay the row of pavers and place the 1/4-inch spacers between each of the paver stones or bricks. Repeat the process until the targeted area is covered with pavers. Allow the mortar 24 hours to dry before proceeding.
Mix the grout according to the package instructions. Use a grout sponge to spread the grout into the spaces between each of the pavers. Be sure to fill each of the spaces until they are even with the top of the paver. Allow the grout 24 hours to dry before walking on the patio or proceeding.
Rinse the surface of the patio with a hose and use a sponge to wipe off the top surface of the pavers.