Our Rip Rap (RSP) Rock is a durable, angular stone designed for erosion control, slope stabilization, drainage channels, and heavy-duty landscaping applications across Marin, Napa, Sonoma, and Solano counties. Produced to Caltrans and local specifications, Rip Rap provides long-lasting protection against water flow, soil movement, and washouts.
 
Rip Rap (RSP) is available in multiple sizes to suit residential, commercial, and municipal projects:
2"–3" Small-scale decorative drainage swales and erosion barriers
3"–6" Light erosion control, driveways, and culvert outfalls
4"–9" General slope protection, stream banks, and construction pads
9"–18"  (#1 Backing Rock) Heavy-duty shoreline, levee, and hillside stabilization
Oversized boulders – Available upon request for custom orders
 
Common Applications
Drainage channels & culverts
Slope protection & levees
Shoreline & streambank reinforcement
Construction site stabilization
Decorative large rock accents
 
Material Specifications
Material Name: Rip Rap Rock (RSP)
Source: Northern California quarries (meets Caltrans & ASTM standards)
Material Type: Crushed Rock / Erosion Control Stone
Color: Natural gray, with occasional tan and rust variations
Form: Angular, rough fractured faces for interlocking stability
 
Technical Properties
Density (avg): 1.6 tons per cubic yard
Unit Weight: 120–135 lbs/ft³
Absorption: ≤ 2% (typical for basalt/granite sources)
Durability: High resistance to weathering and freeze–thaw cycles
Compaction: Interlocking angular structure provides stability without compaction
 
Compliance Standards
Caltrans Section 72 – Rock Slope Protection (RSP)
ASTM D4992 – Standard Practice for Preparation of Rock Slopes
ASTM C88 – Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate
ASTM C131/C535 – Resistance to Degradation (Los Angeles Abrasion Test)
 
Packing & Delivery Information
Minimum Order: 5 tons required per delivery
Packaging: Delivered loose in bulk by dump truck
Handling: Material is heavy and angular; may cause scratching, chipping, or damage to pavement, concrete, or asphalt during dumping; take caution when ordering.
Delivery Notes:
Customer must provide clear access for dump truck delivery
Material cannot be placed over fences, walls, or other obstacles
Take precautions when selecting drop location to avoid surface damage
Additional delivery fees apply for remote or difficult-to-access locations
 
⚠️ Important: North Bay Materials or trucking company is not responsible for surface damage caused during standard dumping operations.
Sizes are nominal ranges; natural variation in rock shape and dimension occurs.
Material is sold by the ton; coverage rates are estimates only.
Consult with a licensed engineer for critical erosion control applications.
 
 
Frequently Asked Questions (FAQs) – Rip Rap (RSP)
 
Q1: What is Rip Rap (RSP) used for?
Rip Rap, also called Rock Slope Protection (RSP), is used for erosion control, slope stabilization, drainage channels, culverts, streambanks, and shoreline protection. It prevents soil loss and protects against water damage.
 
Q2: What sizes of Rip Rap are available?
We stock Rip Rap in standard Caltrans sizes:
2"–3"
3"–6"
4"–9"
9"–18"
Oversized boulders are available upon request.
 
Q3: How much Rip Rap do I need for my project?
Coverage depends on the size of Rip Rap and project conditions. For example, one cubic yard (about 1.6 tons) of 4"–9" Rip Rap typically covers 30–40 sq. ft. at a 10" depth. We recommend consulting with your contractor or engineer for exact quantities.
 
Q4: How is Rip Rap RSP delivered?
Rip Rap is delivered in bulk (loose) by dump truck. A minimum order of 5 tons is required. Due to the weight and angular shape of the rock, it can cause surface damage when dumped—so select your drop area carefully.
 
Q5: Does Rip Rap RSP rock meet Caltrans or engineering specifications?
Yes. Our Rip Rap RSP rocks meets Caltrans Section 72 (Rock Slope Protection) requirements and ASTM durability standards, making it suitable for residential, commercial, and municipal projects.