Holding CSLB license #845190 for C-29 Masonry since 2004, STP Masonry operates from 9435 Showplace Drive in La Mesa's Casa de Oro area, building retaining walls, custom fire pits, outdoor barbecue islands, and concrete flatwork across San Diego County. Multi-tier keystone retaining walls engineered for La Mesa's hillside lots require compacted base courses, geogrid reinforcement layers, and proper drainage aggregates behind the wall face — grading work that precedes the landscape planting installed by firms like Botanically Crafted Landscapes. Custom-built outdoor barbecue islands integrate stainless-steel grill inserts, granite or concrete countertops, and gas-line rough-in within a CMU block and stone-veneer shell. Paver installations use interlocking concrete units set on a screeded 1-inch sand bed over compacted road base, with polymeric sand joints that resist weed intrusion and ant tunneling — hardscape work that forms the foundation for the deck framing built by contractors like San Diego Deck Builders on adjacent outdoor-living projects. Structural retaining walls exceeding 4 feet in exposed height require City of La Mesa building permits with engineered drawings specifying rebar placement, footing depth, and lateral earth-pressure calculations per CBC Section 1807.