Landscape boulders are embedded to a depth of one-third their total height into ninety-five percent compacted subgrade or crushed surfacing. Expansion material and sealant topped with sand matching the rock color are installed at interface joints. Pavement or compacted gravel rests on the compacted subgrade adjacent to the rock. Concrete curbs or walls abut the boulder with a minimum two-inch clearance. All boulders require landscape architect approval, field-located placement and orientation, and must be set prior to constructing concrete walks and curbs.
1/3 H MIN. 12" H 1/3 H 2" MIN 1. BOULDER 2. EXPANSION MATERIAL/SEALANT, TOPPED WITH SAND TO MATCH ROCK COLOR 3. PAVEMENT OR COMPACTED GRAVEL 4. 95% COMPACTED SUBGRADE (SEC 312000) OR 4" CRUSHED SURFACING PER WSDOT 9-03.9(3) COMPACTED 95% 5. PLANTING AREA 6. CONC. CURB OR WALL NOTE A. ALL BOULDERS TO BE APPROVED BY LANDSCAPE ARCHITECT. FINAL ORIENTATION AND PLACEMENT TO BE FIELD LOCATED BY LANDSCAPE ARCHITECT. PLACE BOULDERS PRIOR TO BUILDING CONCRETE WALKS AND CURBS. 1 2 6 4 3 2 1 5 5 4 H VARIES 28"MIN.
Members view this detail in full resolution, download the CAD files (SVG, PDF), and can adapt it in the built-in CAD editor — export DXF, DWG, or PDF.
Start membership