Fill dirt belongs deep under a patio, never directly beneath it. Pavers and slabs want a base that compacts hard and stays put — a dense-graded blend of stone and fines, not soil that swells, shrinks, and settles with moisture.
The right layer order
- Deep low spots — fill dirt, compacted in 3–4 inch lifts
- Structural base — 4–6 inches of dense-graded base, compacted hard
- Setting bed — about an inch of sand or stone dust under the pavers
Skipping the base layer to save a step is how patios grow waves by their second spring. See Fill Dirt for deep sub-fill and Dense Pack ¾" to minus for the base, or call or text (617) 645-0987 for layer-by-layer quantities.
