ABC / Road Base
Aggregate base course (ABC), often called road base, is a compactable base material used under driveways, access roads, hardscape, and structural elements. It is part of the core material set Trade Master delivers for Metro Phoenix contractors.
ABC is typically a graded mix of rock and fines designed to compact into a firm, stable base when installed correctly.
Typical Uses
Contractors in the Phoenix area commonly use ABC / road base for:
- Driveway and access-road base layers.
- Base under pavers, slabs, and other hardscape where structural support is needed.
- Pads for sheds, equipment, or small structures where a compacted base is required.
For engineered work or code-driven projects, always follow the design spec and Confirm with dispatch if you need specific ABC gradations (e.g., spec vs non-spec) or documentation.
Spec Highlights & Behavior
From a behavior standpoint:
- ABC is designed to compact well, forming a firm, load-bearing surface.
- Because it contains fines, ABC behaves more like a structural base than a free-draining rock.
- It is generally not used where open drainage voids are the primary goal; in those cases, a cleaner, washed drainage rock may be more appropriate.
Competitor FAQs and resources in the market often distinguish between ABC and decomposed granite / quarter minus, and between structural base materials and decorative or drainage rock. Trade Master respects those distinctions and encourages contractors to align material choice with the job’s goals.
Wrong-Rock Prevention Checklist
To reduce mistakes and disputes on ABC orders, Trade Master uses a wrong-rock prevention checklist consistent with the rest of the site:
- I understand that ABC / road base is a compactable base material, not a decorative finish.
- I understand that ABC contains fines and is designed for compaction and structural support.
- I understand that if I need drainage or decorative rock, a different material may be more appropriate, and I will Confirm with dispatch if unsure.
- I understand that rock and gravel are natural products and can vary in color and appearance from samples and photos.
- I have considered site access and dump location and will review the Delivery Prep Checklist and confirm any special access constraints with dispatch.
On-page confirmation is reinforced visually via:
Wrong-rock prevention checklist
- I understand how this material can look different when wet vs dry.
- I understand the fines / minus / gradation and how it behaves on site.
- I confirm the site has access for the truck (clear approach, dump location, and safety considerations).
On estimate forms, these confirmations must be acknowledged before submitting a request to Trade Master dispatch.
What Dispatch Confirms for ABC / Road Base
When you request ABC / road base, dispatch will:
- Confirm the type of ABC you are requesting (for example, whether you need a particular gradation or spec vs non-spec product).
- Confirm the delivered estimate structure for your job-site address (material, delivery, tax/fuel notes) as an estimate.
- Confirm the delivery window as a time window rather than an exact clock time.
- Confirm access constraints (driveway strength, gates, overhead clearance, slope, potential street-dump needs) before the truck is loaded.
Estimate only — final pricing and delivery window are confirmed by Trade Master dispatch.
If you need documentation such as tickets or photos for your records, mention this when you speak with dispatch so they can align with your requirements.
Frequently Asked Questions
Is this ABC "spec" or "non-spec"?
Some competitors distinguish between engineered/specified ABC and non-spec base. Trade Master can help you understand options but does not set engineering standards. For code- or plan-driven work, always follow the engineer’s or jurisdiction’s requirements and Confirm with dispatch about material options.
Can I use ABC under pavers or concrete?
ABC is commonly used as a base under pavers and concrete. Exact depth and compaction requirements depend on the design; always follow the project spec and Confirm with dispatch if you have questions about material suitability.
What if I need cleaner drainage instead of a compacted base?
If drainage is the priority, you may want a washed or drainage-specific rock instead of ABC. Share your use case with dispatch, and they can help you avoid choosing a base material where drainage rock is more appropriate.