Perlite
Perlite is sodium potassium aluminosilicate, it is a naturally occurring mineral, and therefore non-renewable. It a dark grey type of volcanic glass which formed when volcanic obsidian glass is saturated in water over a long period.
In its natural raw state it has a density of around 1100 kg/m3 and solid, it is generally more commonly known in its expanded or processed state. When heated to temperatures of up to 980-C it softens and the entrapped water is released as steam which causes particles in their plastic state to expand up to 20 times their original size.
The expanded form of perlite has a density of between 30–150 kg/m3, a neutral pH level, efficient at absorbing small amounts of water, and draining water as it is spherical and with some insulating qualities due to its inherent air gaps.
It has been used in agriculture for many centuries, partly because the volcanic areas where it is found are also fertile soils. Today it is used in common gardening, hydroponics and in construction as a lightweight aggregate in concrete, as filling material, acoustic or insulation application and in fireproofing.
The global reserves of perlite are estimated to be around 700 million tonnes, with around 500,00 tonnes produced each year primarily from Greece, the US, Turkey, and Japan. Vermiculite is a very similar material to perlite with similar uses but some slightly different characteristics.
[edit] Related articles on Designing Buildings
- Composites.
- Deleterious materials in construction.
- Insulating plaster.
- Materials.
- Metal in construction.
- Phase change materials..
- Sustainable materials for construction.
- Types of biobased materials.
- Types of materials.
- Use of ceramics in construction.
- Vermiculite.
[edit] External links
Featured articles and news
C20 Society; Buildings at Risk List 2025
10 more buildings published with updates on the past decade of buildings featured.
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation, closing 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.