Applications

Environmental

Engineered Media for
Environmental Performance.

Stalite Environmental delivers engineered lightweight media solutions for green infrastructure and environmental systems where load reduction, drainage, and long-term stability are essential. By combining expanded slate lightweight aggregate with select natural materials, Stalite Environmental supports predictable hydraulic performance, plant health, and structural efficiency across green roofs, bioretention systems, planters, and specialty environmental applications.

Lightweight aggregate used across environmental applications including green infrastructure, planting systems, and drainage layers
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Green infrastructure walkway featuring planted stormwater media and lightweight aggregate for drainage and stability

Environmental Applications
using Lightweight Aggregate

Stalite Environmental provides engineered media designed to meet the performance demands of modern green infrastructure and environmental construction. Lightweight aggregate blends are developed to balance drainage, moisture retention, aeration, and structural load reduction, supporting successful installation and long-term function across a wide range of environmental applications.

These engineered media systems help designers and engineers meet stormwater management goals, reduce dead loads on structures, and maintain stable growing environments without the degradation, compaction, or variability associated with conventional organic materials.

Each application includes specifications, test data, and research available for download. Stalite’s technical team regularly assists with mix development, submittal review, and performance guidance to ensure media selections meet hydraulic, horticultural, and structural criteria.

Key Benefits

  • Reduced Structural Loading
    Lightweight aggregate lowers dead load on roofs, structures, and site systems without compromising performance.

  • Long-term Media Stability
    Expanded slate does not break down, compact, or decompose over time.

  • Improved Plant Performance
    Balanced air and water retention supports root development and nutrient availability.

  • Durable and Inert Material
    Maintains performance under wet-dry cycles, freeze-thaw conditions, and continuous exposure.

  • Sustainable Material Attributes
    Manufactured from natural shale and qualifies as a pre-consumer recycled product.

Common Uses

  • Green roofs (extensive, intensive, and rooftop stormwater systems)
  • Bioretention systems and rain gardens
  • Planters and living walls
  • Media filters and infiltration basins
  • Lightweight structural and environmental fills
  • Specialty horticultural and filtration applications

Environmental Applications

Discovery Place green roof in Charlotte, NC using engineered lightweight media to support vegetation, drainage, and reduced structural loadGreen Roof Media

Stalite has supplied lightweight green roof media for more than 20 years, supporting over 600 projects and more than two million square feet of vegetated roof area. Expanded slate blends provide consistent drainage, moisture retention, aeration, and long-term stability for extensive, intensive, lawn, and rooftop stormwater systems.

Benefits include high permeability, deep root aeration, balanced pH, and excellent cation exchange capacity for nutrient retention. Media meets FLL guidelines, is available in bulk or super sacks, can be blown into place, and supports efficient rooftop installation.

Turf grass roots penetrating engineered filtration media, illustrating improved drainage and root developmentFiltration & Bioretention Media

Stalite expanded slate sands and blends are used in bioretention systems and media filters to support effective stormwater treatment and infiltration. Angular, porous particles maintain consistent hydraulic conductivity, reduce clogging risk, and support healthy microbial and root activity essential for long-term system performance.

Research demonstrates improved pollutant removal compared to many conventional and proprietary media mixes, supporting reliable stormwater management outcomes.

Flower bulbs planted in soil conditioned with lightweight aggregate to improve drainage, aeration, and long-term soil structure

PermaTill® Horticultural Media & Soil Conditioning

PermaTill improves aeration, drainage, and long-term structure in planting soils and container mixes. Unlike perlite or bark, PermaTill does not degrade over time, helping prevent compaction and maintain consistent air and water movement.

Applications include potting mixes, landscape beds, vegetable gardens, succulents, bulbs, and specialty planting systems where long-term media stability is critical.

Planting bed using lightweight aggregate–amended media to improve drainage, aeration, and long-term soil structureAquaculture & Aquaponics Media

In aquaponic systems, Stalite serves as a clean, durable substrate that supports root anchoring, microbial activity, and nutrient cycling. Porous particles provide surface area for beneficial bacteria while allowing efficient water circulation between tanks and planting cells.

Lightweight aggregate used for root and bulb protection while improving drainage and soil aerationPermaTill® VoleBloc Root & Bulb Protection

PermaTill VoleBloc provides a permanent, non-toxic physical barrier that protects bulbs, roots, and plantings from vole damage. Coarse, angular particles prevent burrowing while simultaneously improving soil aeration, drainage, and nutrient storage.

Related Case Studies

Atlanta City Hall Green Roof

Atlanta City Hall green roof terrace featuring engineered planting media made with Stalite’s PermaTill expanded slate aggregate.

3,300 sq. ft. green roof at Atlanta City Hall highlighting sustainable rooftop design and engineered green roof systems.

Hospice of Wake County

Stormwater filtration demonstration at Hospice of Wake County showing runoff water clarified after passing through Stalite Lightweight Aggregate filtration media.

Stormwater harvesting system in Raleigh using lightweight expanded slate filtration media to capture, treat, and reuse rainwater for landscape irrigation.

Gateway Village

Gateway Village rooftop garden courtyard in Charlotte constructed with lightweight structural soil using Stalite Lightweight Aggregate.

Urban rooftop garden at Gateway Village in Charlotte built with lightweight structural soil for rooftop landscaping.

Supporting Documents

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Frequently Asked Questions

Stalite is commonly used in green roofs, bioretention media, stormwater filters, planters, and lightweight structural fills to reduce dead load and improve drainage and infiltration.

Yes. Stalite is frequently blended into engineered green roof mixes because it is lightweight, stable, and provides good water retention and drainage.

Stalite offers high infiltration rates, low fines, and stable long-term performance, making it useful in bioretention, media filters, and infiltration systems where consistent hydraulic conductivity is required.

Expanded slate is lighter, more durable, and more consistent than natural soils. It supports drainage, doesn’t compact as quickly, and maintains performance over time.

Yes. Because Stalite weighs significantly less than traditional aggregates, it helps reduce dead load for rooftop planters, green roofs, and elevated landscape systems.

Yes. Stalite can be blended with sand, organics, and other materials to meet specific hydraulic, structural, or horticultural requirements.

Yes. Stalite is inert, stable, and supports root development in rooftop planters, urban trees, and engineered soils.

Yes. Stalite can be pneumatically blown or placed via conveyors, making it practical for projects with limited access or height constraints.

Infiltration rates vary based on mix design, but Stalite-based media generally meet or exceed typical bioretention specifications for hydraulic conductivity.

Yes. Stalite blends can be designed to comply with common municipal, state, and LEED-related environmental performance standards.