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Rip Rap Slope Protection and Department of Transportation Projects
Generally this involves rock materials from large landscape rubble to 2 ton angular boulders. This rock is chosen as a result of lab tests showing the strength of the rock as opposed to landscape rip rap which is chosen by color. Engineering grade rip rap ranges from decorative slope rock blanket material of 4 inches or greater to stabilization material 1/4 ton to 2 tons per boulder.

Slope Protection Rock Should Demonstrate
Stability: Angular shapes may be used on any planed slope
Durability: Resist degradation and have a durability of 52 minimum (Caltrans)
Consistency: Product is the same load after load.
Meets Specification: No rejections due to inferior material, complies with all project specific specifications, or to Caltrans or Army Corps specifications.
Availability: Product is locally available when needed.

Angular vs Rounded Cobbles
Angular or crushed rock is used in most applications due to its interlocking qualities. Rounded or cobble rock is not specified by Caltrans for projects with a slope greater than 1:2 (vertical: horizontal)
Most Public Agencies in Central California specify that Stone Protection (Rip Rap) meet Section 72 of the Caltrans Standard Specifications. Caltrans standards set limits for Gradation or Size, Apparent Specific Gravity, Absorption, and Durability Index. Suitable Slope Protection (Rip Rap) materials demonstrate test results that consistently meet these standards. Caltrans identifies eleven different sizes and two placement methods.
The sizes as specified by Caltrans are: 8 ton, 4 ton, 2 ton, 1 ton, ½ ton, ¼ ton, Light, and No. 1, No. 2 or No. 3 Backing.

The Placement Methods Designated By CalTrans
Method A Placement
Method B Placement
The principal differences in the two placement methods are the size range of the rock specified and actual placement mechanism. Method A requires placement of individual stones, while Method B allows placement by dumping or dozing. Refer to the project special provisions for Placement Method and additional direction.
Both private and public work projects can use either the Caltrans Standard Specifications or specify by average size of Rip Rap i.e. 2 foot or 3 foot rock, additionally a size range can be specified, such as 15 to 24 . Please keep in mind that material specifications can be modified in the Project Special Provisions Documents
  • Make certain of the Product Required Project Service Requirements
  • Product Name
  • Product Maximum / Minimum Size
  • Specifying Agency (Caltrans, Green Book, Army Corp or Other)
  • Special Provisions addressing additional specifications
  • Certification Required (Submittals) Caltrans, Army Corps, other agency or engineer
  • Quantity Required (Specific Gravity—Conversion Tons to Cubic Yards)
  • Product Availability (Available when required, can handle Daily Shipping Requirements)
  • Technical Support Required (Lab Work)
When ordering use the Purchase Order function at checkout and enter ROCK as your payment method. This will allow you to create an order for a firm transportation quote without having to pay for it at this time. While we have posted transport rates, in many circumstances we are able to ship the order to you for less. You will be given a firm cost on the whole order within a few minutes to a few hours.
Engineering grade rip rap