#8 Trap Rock (3/8")

#8 Trap Rock (3/8") Crushed Stone - Product Overview

#8 Trap Rock (3/8"), also known as #8 Crushed Trap Rock, 3/8" Trap Rock, #8 Aggregate (Trap Rock), 3/8" Clean Stone (Trap Rock), or ASTM #8 Trap Rock, is a hard, durable crushed igneous rock. It is typically produced from basalt or diabase, resulting in angular particles that promote interlocking within the aggregate. The stone is dark gray to black, washed to remove fines, and non-reactive, making it stable and resistant to weathering and abrasion. The nominal particle size is 3/8 inch (approximately 9.5 mm), with material passing a 1/2" sieve and retained on a No. 4 sieve, in compliance with ASTM C33 and AASHTO M43 #8 gradation standards.

Main Characteristics

• Crushed, angular shape for strong interlock
• Nominal size: 3/8" (approx. 9.5 mm)
• Hard, dense, durable igneous rock (usually basalt or diabase)
• Washed/cleaned to remove fines; low in organic material
• High resistance to abrasion and weathering
• Bulk density: approx. 100-120 lbs/ft³
• Specific gravity: approx. 2.6-3.0
• Absorption: typically less than 2%

Functional Uses and Performance

#8 Trap Rock is valued for its ability to create a stable, well-draining surface. Its angular shape allows the material to interlock, making it ideal as a finer top layer on pathways and patios, or as a top base under pavers. Water drains efficiently through the gaps between particles, reducing pooling and promoting longevity in pedestrian and light-traffic areas. The uniform size and hardness of the stone help maintain surface integrity and resist displacement under load. This aggregate is also used in drainage systems, such as French drains and pipe bedding, where its clean, non-compactable nature allows for effective water flow and soil filtration.

Typical Applications

• Top layer for pathways and patios
• Top base layer under pavers and slabs
• Drainage systems (French drains, pipe bedding)
• Backfill for retaining walls
• Decorative landscaping stone
• Road surface treatments and erosion control
• Filter stone in construction
• Roofing ballast (in some cases)

Installation and Handling Guidelines

Proper performance of #8 Trap Rock depends on correct site preparation and installation. The subgrade should be well-compacted and free of organic debris to avoid settling and maintain drainage. Install the stone in layers no thicker than 3 inches, compacting each layer to optimize stability. Edge restraints help keep the material in place, preserving the structure of pathways or patios. The surface may be finished with a finer material or stabilized with binders as needed for the project.

Limitations and Incorrect Applications

#8 Trap Rock is not suitable for every use. It should not be used where fine grading or tight compaction is required, such as a base for driveways or roads that need a compacted subbase. This product is not appropriate as a sand or fine aggregate in concrete, nor is it recommended for playground surfaces or other areas requiring cushioning. It is not suitable where a smooth, rounded aggregate is needed, and may not be appropriate for high-alkali environments unless tested for reactivity. Always check project requirements and specifications before selecting this material.

Technical Specifications

Material Comparison

#8 Trap Rock differs from other aggregates in several key ways. Compared to limestone #8, trap rock is generally harder and more durable. Unlike rounded pea gravel, trap rock is angular, which provides better interlock and stability. Granite #8 is also hard and durable, but differs in color and mineral composition. Trap rock is a virgin, non-recycled material, offering greater consistency than recycled concrete aggregate. It is coarser than sand, making it unsuitable as a fine aggregate.

Pricing and Delivery Examples

Pricing for #8 Trap Rock varies by location due to sourcing and delivery logistics. All prices shown include delivery to your specified address. Enter your ZIP code on our website to see exact pricing for your area. Below are sample prices for selected cities across the US.

Ordering and Delivery with Gravelshop

At Gravelshop, you can order #8 Trap Rock online in less than a minute. All prices shown include delivery, with no hidden fees. Our system provides instant, location-matched pricing from local suppliers based on your ZIP code. You can select your preferred delivery date and time during checkout. Gravelshop supplies aggregates in 31 U.S. states, with delivery carried out by independent trucking companies. Minimum order quantities vary by location. We do not offer material spreading services, but tail-gated dumping may be available at the driver's discretion.

After placing your order, you will receive a confirmation email with payment and shipping details. Our customer care team is available by phone, email, or SMS to answer questions and provide support. All transactions are governed by US law and practices, and payment can be made online using major credit cards and payment platforms. Please review our terms and conditions for full details on delivery and returns.

Quick Reference: When to Use and Not Use #8 Trap Rock

Summary

#8 Trap Rock (3/8") is a washed, angular, hard, and durable crushed stone, ideal as a finer top layer for pathways, patios, and as a top base under pavers. The material interlocks for stability and allows efficient drainage, making it suitable for a variety of construction and landscaping applications. It is not intended for compacted sub-base, sand replacement, or cushioning uses. Gravelshop offers easy online ordering, all-inclusive pricing, and reliable delivery across much of the United States. For more information or to order, visit our website or contact our customer care team.