For landscape architects & specifiers · CSI Division 32 · LEED
Permeable pavement specification, LEED credit mapping, and submittal-ready documentation
Flexus is engineered to drop directly into your project manual. CSI three-part format specification under Division 32, full LEED v4 / v4.1 credit contribution mapping, ASTM and EPA test reports, and editable cross-section details — packaged as a single submittal-ready spec pack.
CSI Division 32 — drop-in specification
Flexus is specified under CSI Division 32 — Exterior Improvements. The Flexus specification is delivered in editable CSI three-part format so it can be adapted to project-specific requirements without rewriting the document.
| Specification element | Flexus reference |
|---|---|
| CSI division | Division 32 — Exterior Improvements |
| Primary section | 32 14 13 — Permeable Unit Paving (or 32 14 16 — Permeable Surfacing, per project manual conventions) |
| Format | CSI three-part (Part 1 General, Part 2 Products, Part 3 Execution), editable |
| Related sections | 31 23 23 (Fill), 32 13 13 (Concrete Paving — for edge restraints), 32 17 23 (Pavement Markings — where applicable) |
| Performance requirements | Permeability per ASTM F1551, slip resistance per ASTM E303, abrasion resistance per ASTM C501 |
| Product data | Series (CP or AP), lift thickness (1.5″ / 2.0″ / 2.5″), aggregate blend, binder type, base specification |
| Submittals | Manufacturer's data, mix design, ASTM/EPA test reports, installer qualifications, mock-up |
| Quality assurance | Manufacturer-installed by Flexus in-house crews, mock-up panel, in-process permeability verification (optional) |
Specification language is available on request as part of the full spec pack. Request spec pack →
LEED v4 / v4.1 credit contribution
Flexus can contribute to multiple LEED v4 and v4.1 credits depending on project scope, design integration, and documentation. The table below shows credits where Flexus has direct or supporting contribution potential. Actual credit award is determined by USGBC during certification review.
| LEED credit category | Credit | Flexus contribution |
|---|---|---|
| Sustainable Sites | SS Credit: Rainwater Management | Direct — Flexus functions as a permeable surface, reducing effective impervious area and supporting on-site stormwater management to the 95th percentile event or local equivalent |
| Sustainable Sites | SS Credit: Heat Island Reduction (Non-roof) | Supporting — surface solar reflectance (SR) varies by aggregate blend. AP series light-tone blends and CP-150 neutral blend can contribute toward non-roof SR requirements; SR documentation available on request |
| Sustainable Sites | SS Credit: Open Space | Supporting — Flexus paths within open-space areas can support open-space credit calculations where local definitions accept permeable surfaces |
| Sustainable Sites | SS Credit: Site Development — Protect or Restore Habitat | Supporting — replacing impervious cover with Flexus reduces hardscape impact in restoration zones |
| Materials & Resources | MR Credit: Building Product Disclosure & Optimization — Sourcing of Raw Materials | Supporting — the SBR rubber component is post-consumer recycled content (sourced from end-of-life tire rubber); documentation provided in spec pack |
| Materials & Resources | MR Credit: Building Product Disclosure & Optimization — Material Ingredients | Supporting — material ingredient documentation available on request to assist with credit pursuit |
| Innovation | Innovation Credit (ID) | Potential — projects integrating Flexus into a stormwater treatment train that exceeds Rainwater Management prerequisites may pursue an ID credit for exemplary performance |
LEED credit contribution is project-specific. Flexus does not award credits — credit attainment is determined by USGBC based on the complete project submission. The information above is provided to support credit pursuit and is documented in the spec pack with applicable test data and material disclosures.
Submittal package contents
Everything required for a complete Division 32 submittal — packaged as a single spec pack and available on request.
01 — Specification
CSI Division 32
Three-part format specification, editable. Section 32 14 13 / 32 14 16 — Permeable Pavement.
02 — Test reports
7 reports
ASTM C501, F1551, E303, D2859, G154; EPA 1311, 1312; RCRA metals. PDFs included.
03 — Drawings
Cross-sections
Typical cross-section detail. Edge restraint detail options. Base preparation detail.
04 — Installation
Field guidelines
Installer qualifications, base prep tolerances, mix proportioning, pour sequencing, cure conditions.
05 — Maintenance
Protocol
Owner-handoff maintenance protocol. Debris management, surface rinsing intervals, repair procedures.
06 — Sustainability
LEED docs
Recycled content documentation, solar reflectance data by blend, rainwater management contribution narrative.
Specifier FAQ
Questions from landscape architects, civil engineers, and specifiers preparing a Flexus permeable pavement section.
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Flexus is specified under CSI Division 32 — Exterior Improvements. The most applicable section numbers are 32 14 13 (Permeable Unit Paving) for the permeable pavement category, or 32 14 16 (Permeable Surfacing) where the project manual uses that designation. The Flexus specification is provided as editable Division 32 language in the spec pack and can be adapted to project-specific lift, base, and edge restraint conditions.
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Flexus can contribute to LEED v4 / v4.1 credits including Sustainable Sites (Rainwater Management for permeable surface, Heat Island Reduction for non-roof SR value, Open Space contributions), Materials & Resources (Building Product Disclosure and Optimization for recycled content from the SBR component), and Innovation in Design where stormwater treatment trains exceed prerequisites. Actual credit contribution depends on project design, scope, and documentation submitted to the certifying body. The spec pack includes documentation to support credit pursuit.
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Yes. A CSI three-part format specification for Flexus permeable pavement is available as part of the submittal-ready spec pack. The specification is formatted for Division 32 and is provided in editable form so it can be adapted to project-specific requirements including series (CP or AP), lift thickness, aggregate blend, base specification, and edge restraint conditions. Sealed copies tied to a live project can be requested through the Resources page or by contacting us directly.
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Flexus is a proprietary permeable pavement system within the broader category of resin-bound permeable pavements. The closest industry standards reference for permeable pavement system design is ASCE 68-18 (Permeable Interlocking Concrete Pavement) — which addresses PICP specifically but provides relevant context for permeable pavement site suitability, subbase design, and hydrologic sizing principles that apply to Flexus installations. Individual ASTM standards (C501, F1551, E303, D2859, G154) and EPA methods (1311, 1312, RCRA) are referenced directly in the Flexus spec pack.
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The Flexus submittal package — referred to as the spec pack — includes the product overview, CSI Division 32 specification language, installation guidelines, typical cross-section details, edge restraint detail options, ASTM test reports (C501 abrasion, F1551 permeability, E303 slip resistance, D2859 water absorption, G154 UV exposure), EPA leaching test reports (1311 TCLP, 1312 SPLP, RCRA metals), maintenance protocol, and LEED credit documentation. The complete package is available on request.
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Flexus is designed to meet the ADA surface requirements of firm, stable, and slip-resistant when properly installed. Slip resistance is documented via ASTM E303 in the spec pack. Cross-slope must not exceed 2% and running slope must comply with applicable accessibility standards — these are field conditions controlled by the design and installation, not by the material itself. The specifier and contractor are responsible for confirming that the installed route meets local accessibility requirements.
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Yes. The Flexus Division 32 specification is provided in editable format. Project-specific edits typically include selecting between CP and AP series, lift thickness (1.5″ / 2.0″ / 2.5″), aggregate blend (standard CP or curated AP blends), base aggregate gradation, base depth (driven by stormwater storage and structural requirements), edge restraint type, and accessibility scope. We can review draft specifications on request before they are issued.
Specify with confidence
Pull the complete spec pack to draft your Division 32 section. Request a physical sample to verify surface character before specifying. Both are one step away.