#57 Stone: Clean Drainage Rock for Ledge and Frost Country

People order #57 stone when they meant 3/4 inch crushed stone, and the other way round, about equally often. The two overlap in size and do not always do the same job. Sorting that out first saves a load.

This one is 3/16 inch to 1 inch, graded to the #57 specification, and angular crushed rock. Nothing fine in it. That is the point.

Is #57 Stone the same as 3/4 inch crushed stone?

Close, not identical.

Both are washed, angular and roughly the same size on a shovel. #57 is a graded band with a stated range of 3/16 inch to 1 inch, which is what an engineer or a concrete mix is asking for when the number appears on a drawing. 3/4 inch crushed stone is sold by its size rather than by a grading number.

For a drain trench at a camp, either will move water. If the drawing says #57, order #57. If you are also batching concrete or backfilling a wall that someone engineered, the number matters.

What does it do at a downspout that pea stone cannot?

Rounded stone packs. Angular stone does not.

Pea stone at a splash area looks tidy for a season, then the rounded pieces settle together, silt fills what gaps remain, and the water starts running across the top instead of down through it. The angular faces on #57 hold each other apart, so the spaces between pieces stay connected and open.

That is the whole reason it goes in French drains, curtain drains, foundation runs and behind retaining walls. Water gets a path out rather than building pressure against the wall.

How much goes behind 40 feet of retaining wall?

A hypothetical job. A 40 foot wall standing 3 feet high, with a 12 inch chimney of stone against the back of it.

• 40 ft long x 1 ft wide = 40 sq ft in plan
• 40 x 3 ft high = 120 cu ft
• 120 / 27 = 4.44 cu yd

Two smaller jobs from the same trip:

Downspout splash area, 4 ft by 6 ft, 4 inches deep

• 4 x 6 = 24 sq ft
• 24 x 4 / 12 = 8 cu ft
• 8 / 27 = 0.30 cu yd

Pond or shoreline edge, 50 ft by 4 ft, 6 inches deep

• 50 x 4 = 200 sq ft
• 200 x 6 / 12 = 100 cu ft
• 100 / 27 = 3.70 cu yd

At the roughly 2,800 lb per cubic yard this site publishes for #57 crushed stone, near enough to 1.40 tons per yard, those volumes come out at about 6.2 tons behind the wall (4.44 x 1.40), 0.4 tons at the splash area (0.30 x 1.40) and 5.2 tons along the pond edge (3.70 x 1.40). Treat those tonnages as approximate, and run other shapes and depths through the stone calculator before you order.

Will it stay put along a pond edge in spring?

Depends what the water is doing.

On a quiet pond edge or a slow ditch line, yes. A 6 inch layer over fabric holds, and the open spaces let water pass through the bank rather than undercutting it.

On a lakeshore taking wind and boat wake, or at a culvert outlet with spring runoff coming through it, no. Water that can move a 1 inch stone will move all of them, and by June the layer is downstream. That is RipRap work, with stone measured in inches across rather than fractions of one.

The honest test: if you have watched that spot move stone before, go heavier.

Can it sit on the camp road, or does it stay in the drain?

It can surface a drive, and plenty do it. Know the trade before you commit.

A clean stone with no fines will not bind. It stays loose, it migrates to the edges under tires, and it does not hold a crown. Under a boot or a bike tire it rolls. What it gives you in return is a surface that drains hard and does not turn to mud, which on dense till with a spring problem can be worth the nuisance.

Better on most New Hampshire roads: a compacted base of crushed gravel with a surfacing course over it, and the clean stone kept for the drainage work. Mixed use is where people waste a load.

What does the truck need when the load is clean stone?

Washed stone rolls when it lands, so the pile spreads wider than a load of base material does. Allow for that when you choose the dump spot.

Firm ground, room to back, clear height for the body. Camp-road branches stop more deliveries than soft ground does.

A tarp under the drop is worth laying if the stone is landing on grass or on a finished drive. Clean stone shows every piece you leave behind, and raking washed rock out of turf is slow work.

If the drain trench is dug and open, do not have the pile tipped alongside the edge. Stone rolling into an open trench before the pipe and fabric are in will cost you an afternoon.

Set quantity and delivery date on this page. Delivery is arranged at checkout by ZIP code. If the drawing you are working from names a grade this catalogue does not carry, ask New Hampshire Rock Supply from the contact page before you order.