LiGrA as a Sustainable Replacement for Expanded Perlite in Construction

Introduction

Expanded perlite is widely used in roof insulation screeds, lightweight plaster, and horticulture because of its porous structure and thermal properties. But perlite is mined from volcanic rock, then heated above 800–1,000°C to expand, making it energy-intensive, imported, and costly in regions without natural deposits.

LiGrA (Lightweight Green Aggregates), manufactured from recycled glass fines and industrial ash through controlled foaming and sintering, offers a local, low-carbon, and circular alternative. Unlike perlite, LiGrA also encapsulates heavy metals from industrial ash into a vitrified structure, preventing leaching and making construction materials safer.

The Challenge with Perlite

• Costly Imports: In Southeast Asia, perlite is fully imported at ~USD $200/m³.
  

• Energy & Environment: Mining and high-temperature expansion release significant CO₂.
  

• Brittle: Perlite breaks down into dust, reducing durability in screeds and handling.
  

• No Waste Value: Perlite does not address industrial waste streams or recycling goals.
  
  

Real-World Precedent

Expanded perlite has been used successfully for decades in insulation:

• Singapore HDB flats (1970s–90s): perlite screeds specified for lightweight insulation on flat concrete roofs.
  

• Malaysia & Thailand (2000s–present): imported perlite used in lightweight plaster and mortars for green-certified buildings.

• Europe: perlite widely used in roof insulation systems (e.g., Knauf Insulation perlite screeds).
  
  

These projects validate perlite’s value as an insulator — but also highlight its dependence on mining and imports.

The LiGrA Solution

LiGrA replicates perlite’s thermal and lightweight performance, while improving sustainability and safety:

• Lightweight density: 300–600 kg/m³ (vs. perlite ~100–150 kg/m³, but more durable).
  

• Thermal conductivity: 0.04–0.06 W/mK.
  

• Sintering + encapsulation: Heavy metals in ash (e.g., Pb, Cr, Cd) locked into a glass matrix.
  

• No leaching: Rainwater tests show negligible release, ensuring safe long-term use in screeds and plasters.
  

• Circular economy: Diverts glass and ash waste into building-grade material.
  
  

Hypothetical Project: Kuala Lumpur Apartment Block

Scenario: A 10-storey, 100-unit housing block requires a 100 mm insulation screed over its 2,000 m² flat roof.

• Volume required: 200 m³ lightweight aggregate.
  
  

1) Cost Comparison

• Imported perlite: $200/m³ × 200 m³ = $40,000
  

• LiGrA: $150/m³ × 200 m³ = $30,000
  

• Direct saving = $10,000 upfront
  
  

2) Energy Savings for Residents

• LiGrA screed improves roof insulation → 10% less cooling load.
  

• Average AC bill = $50/month/unit.
  

• Savings per unit = $5/month.
  

• 100 units × $5 × 12 = $6,000/year saved on electricity.
  
  

3) Environmental Impact

• Each m³ of LiGrA uses ~800 kg of waste (glass + ash).
  

• 200 m³ = 160 tons of waste diverted from landfill.
  

• Encapsulation locks in ~32 kg of toxic lead equivalent, preventing future leaching.
  

• Perlite expansion typically emits ~1.2 t CO₂ per 100 m³.
  

• Switching to LiGrA saves ~1 t CO₂ per project.
  
  

Before vs After 

👉 “From $10,000 upfront savings to $6,000 less on AC bills every year, plus 160 tons of waste recycled — LiGrA makes every roof screed a win for cost, comfort, and the environment.”

Conclusion

Perlite has proven its value in insulation for decades — from Singapore’s HDB flats to global green buildings. But it comes with import dependency, mining impacts, and high costs. LiGrA provides the next step forward: a locally produced, circular, and safer replacement. By combining insulation performance with waste detoxification, LiGrA is not just a building material — it’s a sustainability solution for modern construction.