Perlite.
Perlite is a natural material with a moderate CO₂ footprint — significantly lower than EPS and XPS. Well suited as a plastic-free alternative in moisture- and fire-exposed constructions. Read the numbers together with function, lifespan, detailing and the specific building element.
- Carbon Footprint (GWP)
- 0.48 kg CO₂-eq/kg
- Source: estimatee based on the EN 15804 average
- Density
- 50–150 kg/m³
- Expected Lifespan
- 100+ years (inorganic and does not degrade)
How to use this assessment
The assessment of perlite is a first decision basis. Carbon numbers, density and lifespan give a point of comparison, but the material must always be read together with structure, moisture, fire requirements, detailing, maintenance and the condition of the existing building. A good material choice is therefore both a data question and an architectural judgement. The useful next step is to clarify which questions should be examined further before the material is specified in a project.
What is perlite?
Perlite is expanded volcanic glass — a natural material without organic substances. It is inorganic, fireproof, and moisture-resistant. Used as loose-fill insulation under ground floors, for plinths, and in plaster formulations. Lower carbon footprint than EPS and XPS, and it does not degrade.
Carbon Footprint Compared
Negative carbon footprint (green) indicates carbon storage. Data based on EPD averages from ECO Platform and estimates per EN 15804.
Typical Applications
- check_circle Loose fill under ground floors
- check_circle Plinth insulation
- check_circle Insulating render
- check_circle Fire protection
- check_circle Roof terrace substrate
In Renovation
Perlite is used in renovation to insulate cavities and crawl spaces, and as lightweight substrate on roof terraces. It is a good alternative to plastic-based insulation in moist environments.
Questions about perlite
What is perlite made from?
Perlite is a naturally occurring volcanic mineral. It is expanded by heating to 850–900°C, whereby contained water evaporates and creates the characteristic voids. It is completely inorganic and contains no toxic substances.
Is perlite better than EPS for plinths?
Perlite is fireproof and contains no plastic chemicals. It is a genuine alternative to XPS below grade, but has lower compressive strength. For lightly loaded plinths and crawl spaces, perlite granules are a good choice.
Can perlite be used as terrace substrate?
Yes, perlite is suitable as a lightweight substrate on roof terraces — it is light, pressure-stable, draining, and supports plant growth. Often combined with lava stone and compost in extensive green roofs.
What is the insulating capacity (lambda)?
Perlite has a lambda value of approximately 0.045–0.055 W/mK, slightly worse than EPS (0.031–0.040). More thickness is needed to achieve the same insulation.
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