What is open-graded base for pavers?

Open-graded base is a paver foundation built from single-size clean stone with no fine material — typically 6–12" of #57 stone (3/4" clean), topped with 4" of #4 clean stone (1.5"), topped with 2" of #8 stone (3/8" chip) as the setting layer. The gaps between stones let water flow through freely — vs traditional ABC base which is compacted crushed aggregate with fines that sheds water. Non-woven geotextile separates the base from the subgrade below.

When should I use open-graded base instead of ABC?

Use open-graded when: (1) the paver system is permeable (Belgard Aqualine, Pavestone Eco-Priora, Turfstone), (2) the site has drainage or pooling problems that would otherwise require French drains, (3) the project needs to claim stormwater credit for HOA or city approval, (4) the subgrade is expansive clay and needs a decoupled base. Use traditional ABC when: standard non-permeable pavers, well-drained decomposed-granite subgrade, no drainage issue, and no stormwater requirement. Most residential Valley patios still spec ABC — open-graded is a right-tool-for-the-job upgrade, not a universal replacement.

Why is open-graded base 'catching on'?

Three reasons pushing adoption: (1) ICPI (Interlocking Concrete Pavement Institute) has emphasized open-graded systems in updated commercial specs, (2) municipal stormwater rules across the Southwest now credit permeable pavers against impervious-area limits, (3) install crews have found open-graded bases are faster to place (no compaction cycles) and more forgiving to level. For homeowners: better drainage, real stormwater performance, and increasingly the same install cost as premium ABC once the compaction labor is factored.

Is open-graded base more expensive than ABC?

Material-only, open-graded is 15–30% more expensive than ABC — clean stone costs more than crushed aggregate. Installed cost is closer to break-even because open-graded skips the multi-pass compaction cycle ABC requires. For most Valley projects: expect $2–$5/sq ft premium over standard ABC install. On permeable paver systems the premium is required and priced into the paver-specific bid.

Can I use open-graded base under standard (non-permeable) pavers?

Yes, and it's increasingly common for drainage-sensitive sites. The open-graded stone base still supports the pavers correctly, and any water that gets past the joint sand percolates through the base instead of pooling. The tradeoff: joint polymeric sand is critical (it stops joint water from washing base fines that shouldn't be there in the first place), and edge restraint must be robust because the base doesn't lock together the way compacted ABC does. AE will recommend open-graded under standard pavers when the site drainage justifies it.

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Guides · Base Science

Open-graded base for pavers — what it is, when it wins, and why it's catching on.

Name: AE Outdoor Living — Peoria Showroom
Address: 9715 W Peoria Ave, Peoria, AZ, 85345, US
Telephone: (623) 300-2589
Price range: $$$

The new-school paver base spec — single-size clean stone that lets water percolate through instead of shed off. Here's what open-graded is, the exact three-layer stack, and the decision framework for when it beats traditional ABC.

The honest version: Open-graded base is a right-tool-for-the-job upgrade, not a universal replacement for ABC. Most Valley patios and walkways still get standard ABC. But for permeable paver systems, drainage-problem sites, and stormwater-credit projects, open-graded is the correct spec — and getting cheaper to install as crews learn it.

(623) 300-2589 support@aeoutdoorliving.com

What open-graded base is

Single-size clean stone with no fines (no dust, no fill).
3-layer stack: 6–12" #57 stone base → 4" #4 stone leveling → 2" #8 setting layer.
Non-woven geotextile between subgrade and base.
Gaps between stones = free water flow (percolation).
No compaction cycles required — stones lock mechanically.

When open-graded wins

Permeable paver systems (Aqualine, Eco-Priora, Turfstone).
Sites with existing drainage or pooling problems.
Stormwater-credit projects (HOA or municipal).
Expansive-clay subgrade needing decoupled base.
Projects targeting LEED or Green Build credit.

When traditional ABC still wins

Standard non-permeable pavers on well-drained sites.
Decomposed-granite subgrade with natural drainage.
Cost-sensitive projects with no drainage concern.
Tight-budget driveways where fine-graded compaction is proven adequate.

Why open-graded is gaining share

ICPI updated commercial paver specs emphasize open-graded systems.
Municipal stormwater rules credit permeable pavers against impervious-area limits.
Install crews report faster placement (no compaction cycles) and easier leveling.
Homeowner benefit: real drainage performance, no monsoon pooling.

AE's open-graded install spec

Non-woven geotextile over stabilized subgrade.
6–12" #57 clean stone base (depth per traffic load).
4" #4 clean stone leveling layer.
2" #8 chip setting layer, screeded flat.
Pavers set directly on #8 layer.
Joint fill: #8 clean stone for permeable systems, polymeric sand for standard pavers on open-graded base.
Robust edge restraint (spiked aluminum or concrete curb).
3-year AE workmanship warranty.

FAQ

Common questions.

Considering open-graded base for a drainage-critical project?

AE will assess your site drainage, subgrade, and stormwater requirements — and quote both open-graded and traditional ABC options head-to-head so you can decide.

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(623) 300-2589 support@aeoutdoorliving.com

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Why this is an investment, not a cost.

An AE backyard is engineered to add daily livability and long-term home value. We publish honest ranges and build to code with a licensed and bonded Arizona crew. AE provides project-specific workmanship and manufacturer-warranty information in the signed agreement. Website summaries are for planning only.

Licensed, bonded & insured in Arizona. ROC 340966 (R-62) · ROC 341002 (R-3) · ROC 347738 (KA-5) · ROC 211530 (CR-21). Most Arizona contracting work valued at $1,000 or more — or requiring a permit — must be performed by a properly licensed contractor, subject to statutory exemptions. Verify the legal entity, license status, and classification with the Arizona Registrar of Contractors.
Real ranges, itemized scope. You see materials, finishes, equipment models, and a line-item budget before you sign — not a one-line "pool — $90,000."

Open-graded base for pavers — what it is, when it wins, and why it's catching on.

What open-graded base is

When open-graded wins

When traditional ABC still wins

Why open-graded is gaining share

AE's open-graded install spec

Common questions.

Considering open-graded base for a drainage-critical project?

Why this is an investment, not a cost.

Related base-science reading

More open-graded questions?

Keep learning before you build.

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