Installing Perimeter Edging & Setting Slope

Before compacting your final base, you must secure the boundary and define the drainage grade:

• Drainage Slope Rate: Maintain a precise 1% to 2% slope (a 1- to 2-inch drop for every 10 feet of length) angled away from home foundations, retaining walls, or low-lying fence lines. This aligns with standard ASLA residential drainage guides for outdoor living spaces.
• Border Retention (Edging): Without a rigid edge, compacted crushed stone will gradually erode outward into adjacent dirt beds, causing perimeter slumping. Install plastic bender board, concrete edging, or pressure-treated timber around the entire perimeter before spreading your aggregate. The top of your edging should sit 0.5 inches below paved surfaces so the turf pile finishes flush with surrounding hardscapes.

Spreading & Compacting Crushed Sub-Base

A sturdy crushed aggregate sub-base provides structural support while maintaining an open matrix for water percolation. Spread a granular aggregate (such as Class 2 road base or decomposed granite) evenly over the geotextile fabric to a depth of 3 to 4 inches.

• Compaction Technique: Never compact a 4-inch layer all at once. Spread and compact the aggregate in thin 2-inch layers (lifts). Lightly spray a fine mist of water over each lift, then run a heavy plate compactor over the area 3 to 4 times in overlapping passes.
• Quality Check: A properly compacted base should feel rock-hard underfoot. If a heavy boot heel leaves a visible indentation, apply moisture and run the plate compactor again.