For outdoor driveways, car parks, garage ramps and other areas subject to vehicular traffic, 3/4" thick porcelain pavers should normally be laid over a reinforced concrete base using mortar or an appropriate exterior adhesive.
The reinforced concrete base must always be installed in accordance with relevant codes and standards with expansion joints provided as required. If the concrete slab is not sufficiently large to require expansion joints, a minimum 1/8” grout joint between pavers is acceptable, but for larger concrete slabs that require expansion joints, the grout joint should be 3/8”. Pavers must not be installed across expansion joints.
Verify the concrete substrate is in good condition, is installed in accordance with relevant building codes, reinforced with steel mesh and is constructed with a 2° slope pitched away from any building.
Clean the surface of the concrete to ensure good adhesion of the pavers. Spread an approved exterior grade thinset mortar over the concrete using the correct sized notched trowel.
Lay the pavers on the thinset with minimum 1/8” to 3/16“ joint spacing where the area is not large enough to require expansion joints, or with 3/8” spacing where expansion joints are present. All expansion joints must be located along the joint line of the installed pavers to avoid cracking of the pavers.
After the thinset has dried, grout the pavers with an approved exterior grade grout.
Wash the pavers carefully after grouting to remove excess grout.
A final buffered acid wash will also be required to remove any invisible grout residue.
If a polymeric sand is preferred over grout, we recommend Gator Tile Sand which is specifically made for porcelain pavers.