These guys installed cement pavers on adjustable pedestals for my apartment in Brooklyn. Before installation, they redid the new terrace roof because the developer had gotten it wrong. On the day they installed the pavers, it was sunny, humid, and over 100 degrees. The pavers were probably 40 pounds a piece. Despite all this, they took the time to adjust each pedestal and make it all perfectly level. I'm writing this review 5 years later; the work has held up great and the terrace roof has never leaked.