Driveway Weight Limits: How Much Can Your Driveway Handle?
Understanding capacity prevents damage from delivery trucks, RVs, and heavy equipment.
Why Base and Subgrade Matter
While homeowners often focus on the visible surface of their driveway, the hidden layers beneath—the subgrade and base—are actually more critical to long-term performance. A driveway is only as good as what lies beneath it.
Inadequate base preparation is the leading cause of driveway failure. Proper subgrade and base construction ensures decades of reliable service.
The surface layer cannot compensate for poor base preparation. Investing in proper subgrade and base installation pays dividends throughout your driveway's lifespan.
Key Layers at a Glance
- Subgrade: Native soil, compacted to 90% density
- Sub-base: 4-6 inches larger aggregate (when needed)
- Base: 4-8 inches crushed stone, compacted to 95%
- Surface: Concrete, asphalt, pavers, or gravel
Understanding Driveway Layers
Subgrade (Native Soil)
The subgrade is the natural soil beneath your driveway. Proper preparation involves removing organic material, excavating to depth, compacting to 90% density, and ensuring drainage away from the area.
Sub-base Layer
4-6 inches of larger aggregate (2-4 inch stone) used when native soil has poor load-bearing capacity or frost heave potential.
Base Layer
The critical structural component: 4-8 inches of well-graded crushed stone or gravel, compacted to 95% density. Bears vehicle weight and transfers load to the subgrade.
Surface Layer
Concrete (4-8 in), asphalt (2-6 in), pavers (2-4 in bedding), or gravel (4-6 in). Cannot compensate for poor base.
Base Material Options
Crushed Stone
3/4 inch to 1-1/2 inch crushed stone is the premium base: excellent load-bearing, superior drainage, long-lasting. Best for all driveway types.
Crushed Concrete
Eco-friendly recycled option. Lower cost, good performance when properly processed. Quality varies by source.
Road Base (Class 5)
Blend of stone and fines for maximum compaction. Excellent for asphalt, cost-effective, proven performance.
Gravel
Washed gravel: good drainage, lower cost, but less load-bearing. Can shift and rut under heavy loads.
Proper Base Installation
Depth Requirements
Light residential: 4-6 inches. Standard: 6-8 inches. Heavy vehicles/RVs: 8-12+ inches.
Compaction
Compact in 2-4 inch lifts. Plate compactor for small areas, vibratory roller for large. Subgrade: 90% density. Base: 95% density.
Grade and Slope
Minimum 1% slope (1/8 in per ft), recommended 2% (1/4 in per ft). Direction: away from structures.
Signs of Base Failure
Alligator cracking, settlement, potholes, edge crumbling. Professional assessment recommended.
Frequently Asked Questions
Crushed stone (3/4 inch) is generally considered the best driveway base material due to its excellent load-bearing capacity, drainage properties, and long-term stability. Road base (Class 5) is also excellent, particularly for asphalt driveways.
For standard residential use, the base should be 6-8 inches deep. Heavy vehicles require 8-12 inches, while RVs and heavy equipment need 10-12+ inches of properly compacted base material.
Yes, virtually all driveways require a gravel or stone base beneath the surface material. The base provides essential load distribution, drainage, and frost protection. Only some specialized installations on bedrock are exceptions.
An uncompacted base will settle over time, causing the driveway surface to crack, sink, and deteriorate prematurely. Settlement can begin within months and lead to complete driveway failure within 2-5 years, requiring costly replacement.
Subgrade: 90% of maximum dry density. Base layers: 95% of maximum dry density. Use a plate compactor or vibratory roller. Each lift must be compacted before adding the next.
Expansive clay: remove and replace with 12+ inches of suitable fill, install geotextile fabric. Organic soils must be completely removed. High water table: install subsurface drainage or consider permeable materials.
When native soil has poor load-bearing capacity, frost heave potential, or wet conditions. Not all driveways need a separate sub-base—requirements depend on soil conditions and expected loads.
Crushed concrete is a viable eco-friendly option when properly processed. Quality varies by source—ensure it's free of contaminants. Generally good performance at lower cost than virgin stone.