Rip Rap 6"-12"

Rip Rap 6"–12" — Heavy Erosion Control & Drainage Armor Stone

Rip Rap 6"–12" is the bulky, angular armor stone contractors use when a project calls for slowing water down, holding soil in place, or armoring a shoreline against wave action. It is the muscle behind erosion-control projects, drainage swales that have to handle big flow, and the kind of major-grade civil and landscape work where smaller stone simply gets washed away.

At a glance

What it's good for

• Slope erosion control and steep-bank stabilization
• Drainage swales and culvert outlets that handle high flow
• Pond and shoreline armoring against wave erosion
• Heavy-duty foundation drainage and dry well construction
• Driveway sub-base in soft, wet, or unstable soil where a heavy keyed-in foundation is required before crushed stone goes down

How much do I need?

For a 100' shoreline armoring run 4' wide at 12" thick, plan on about 14.8 cubic yards. A drainage swale 50' long × 6' wide at 12" needs about 11 yards. For driveway sub-base over soft ground, plan a 12" lift across the failing area, then cap with 4–6" of Gray Granite 1.5". Always lay rip rap on filter fabric to prevent soil migration up through the stone.

How Rip Rap compares

• vs. Gray Granite 1.5": 1.5" is the transition stone between Rip Rap and fine drainage. Rip Rap is the armor; 1.5" sits on top as the secondary layer.
• vs. Creek Stone 2"–3": Creek Stone is decorative tumbled river stone (smooth). Rip Rap is angular crushed stone for functional armor.
• vs. Boulders: Boulders are placed individually as focal points (12"+ each). Rip Rap is bulk material spread across an area for armor coverage.
• vs. #4 Stone: #4 is 1.5" clean drainage stone — the layer below Rip Rap when both are used together in heavy drainage installs.

Frequently asked questions

What is Rip Rap 6"–12" used for?
Erosion control on slopes, shorelines, and drainage outfalls. Heavy-duty drainage where smaller stone would wash away. Driveway sub-base over very soft or wet soils that need a heavy keyed-in foundation.

Do I need filter fabric under Rip Rap?
Strongly recommended. Non-woven geotextile fabric under Rip Rap prevents soil from migrating up between the stones (which compromises the install). Fabric doubles the lifespan of erosion-control work.

What spec class is this Rip Rap?
Our 6"–12" Rip Rap aligns with MassDOT M2.02.3 Class A2 Stone for Slope Protection / Class B Rip Rap in civil specs. Confirm with your engineer for permit-specified installations.

How thick does Rip Rap need to be?
12" minimum for proper erosion armor. Lighter applications fail under flow. For thicker shoreline applications, 18–24" depending on wave energy.

How much does a cubic yard weigh?
About 2,800–3,000 lbs per cubic yard, or roughly 1.4–1.5 tons.

Do you deliver in the Boston area?
Yes — same-day and next-day bulk delivery across Suffolk, Middlesex, Norfolk, and Plymouth Counties.

Same-day and next-day bulk delivery, no minimum order. We deliver Rip Rap 6"–12" across Plymouth, Middlesex, Norfolk, and Suffolk County.

Pair with our Gray Granite 1.5" or Dense Pack ¾" to minus as the secondary drainage and base layer above the rip rap, or our Coarse Sand for filter-bedding applications.

Order today — the heavy 6"–12" rip rap for erosion control, driveway sub-base, and drainage projects that demand serious stone.

• Same-day & next-day delivery available — weekends fill fast, order early.
• Curbside or on-property drop — let us know at checkout.
• Up to 6 yds per load for dense materials (gravel, soil, rock, sand) — mulch loads carry up to 10 yds. $100 flat rate, no minimum order.
• Job site delivery available — live load tickets and signed BOLs on request.
• Questions? Call (617) 645-0987 or see full delivery info →