Drainage Materials

Septic Rock

Septic rock is clean, washed stone that surrounds the perforated pipes in a septic drain field. Pieces usually run 3/4 inch to 1 1/2 inch, though some counties allow stone up to 2 1/2 inch. The dust and fines get washed out so effluent moves through fast and the pipes stay clear. Most loads look a lot like #57 or #4 stone once they hit the ground.

"Septic rock" names the job the stone does, so the exact spec depends on where you live. Any washed stone that meets your local health code for a leach field qualifies, which is why the same load might get called drain rock or leach rock in the next town over. Check your permit before you order. Some inspectors want a specific gradation, and swapping in the wrong stone can fail an inspection and cost you the whole install.

named grade in this family

What people use it for

Bedding around perforated pipe in a septic drain fieldBackfill over drain field pipe up to the required cover depthBottom stone in a seepage pit or dry well tied to a septic systemCurtain drains and interceptor drains that keep groundwater off a leach fieldBedding under a septic tank on soft or wet sites

How to choose within septic rock

French drain

Washed 3/4" to 1" stone. Angular so it locks around the pipe, washed so it doesn't clog with fines.

Foundation perimeter

Larger clean stone — river rock or #57 — moves water away without holding it.

Downspout dispersion

Cover the splash zone with clean rock so runoff spreads instead of digging a hole.

All septic rock grades

Septic Rock

Drainage systemsSeptic tank leach fieldsFrench drains

Other drainage materials families

Drainage Materials Drain Rock

Reference

Drain rock is washed, clean stone with the fines rinsed out and the pieces sized close to the same.

35 grades→

Drainage Materials Sand

Reference

Drainage sand is a clean, washed sand with the fines rinsed out so water moves through it instead of pooling.

7 grades→

Drainage Materials Rip Rap

Reference

Rip rap is big, angular broken stone placed along creek banks, ponds, and drainage channels to stop water from cutting into the ground.

3 grades→

Drainage Materials Bedding

Reference

Drainage bedding is clean, angular crushed stone that you place under and around a pipe in a trench.

1 grade→

Drainage Materials Fill Material

Reference

Any stone sold as drainage fill has been washed and screened so no dust or sand rides along with it.

1 grade→

Browse all drainage materials families →