What is Leca and what is it made from?

Leca stands for Lightweight Expanded Clay Aggregate. It's made from natural clay fired at around 1,200°C, causing it to expand into small spherical pellets with a porous ceramic-foam interior and a hard, durable outer shell. The result is an ultra-lightweight, inert, pH-neutral aggregate used in construction for lightweight concrete, drainage and insulation, and by gardeners for hydroponics, houseplants and soil improvement.

Are Leca, clay balls, expanded clay and Argex the same thing?

Yes - these are different names for the same product. Leca is the most widely used generic term (Lightweight Expanded Clay Aggregate). Argex is a well-known European brand of expanded clay. Clay balls, clay pebbles, Hydroleca and expanded clay pellets all refer to the same lightweight ceramic aggregate.

What is Leca used for in construction?

In construction, Leca is used for lightweight concrete, lightweight screeds, insulating concrete blocks, vault tiling, precast components, green roof substrates, floor and roof insulation, drainage layers, soakaways and lightweight backfill behind retaining and basement walls. Its low weight, thermal insulation and excellent drainage make it ideal where reducing dead load and improving thermal performance are priorities.

Can I use clay balls for hydroponics?

Yes - Leca clay balls are one of the most popular hydroponic growing media available. They're clean, inert, pH-neutral, reusable and provide excellent aeration and drainage for roots. Ideal for ebb-and-flow (flood and drain) systems, deep water culture (DWC), drip systems, aquaponics and semi-hydroponic houseplant setups. They can be rinsed and reused for years without breaking down.

Are clay balls good for houseplants?

Yes - clay balls are excellent for houseplants. You can use them as a drainage layer at the bottom of pots, as a decorative top dressing to reduce fungus gnats and slow evaporation, or as a complete semi-hydro growing medium for plants like pothos, monstera, orchids, snake plants and philodendrons. Being pH-neutral and rot-proof, they won't harm roots and can be reused indefinitely.

How much Leca / expanded clay do I need?

Leca is sold by volume. Bulk density is approximately 0.3 tonnes per m³ (0/2mm grade approx. 0.55 t/m³). As a guide, 1 cubic metre fills a roughly 2m x 2m area at 250mm depth - ideal for a green roof substrate or thick insulation layer. For drainage behind a retaining wall, allow enough volume to backfill at least 300mm thickness. Call 01635 865679 and we'll help you work out exact quantities.

Is Leca a good insulation material?

Yes - Leca is an excellent loose-fill insulation. Its porous ceramic structure traps air for strong thermal insulation, while its solid ceramic shell makes it fireproof, rot-proof, pest-resistant and unaffected by moisture. Used under floors, between timber joists, in roof build-ups and as an insulating layer under lightweight screeds.

Can Leca be used on green roofs?

Yes - expanded clay is one of the most widely used substrates in green roof construction. Its low weight reduces structural loading, while its porous structure retains water for plants and drains excess away efficiently. It's used both as a drainage layer beneath the substrate and blended into the growing medium itself for extensive and intensive green roof systems.

How is Leca supplied and delivered?

We supply Leca / Expanded Clay in bulk bags, poly bags and loose tipped loads. Bulk bags are ideal for construction and landscaping projects, poly bags are convenient for smaller applications and hydroponics users, and loose tipped loads work well for larger green roof and insulation projects. We deliver across Thatcham, Newbury, Reading, Basingstoke and surrounding areas of Berkshire, North Hampshire and Southern Oxfordshire.

Does Leca meet British and European standards?

Yes - our Leca / Expanded Clay conforms to BS EN 13055, the European Standard for lightweight aggregates used in concrete, mortar, grout and geotechnical applications. This makes it suitable for specification-driven construction projects and architects' specifications where formal standard compliance is required.

Can I use Leca for drainage around foundations or retaining walls?

Yes - Leca is an excellent lightweight backfill for retaining walls, basement walls and building foundations. Its low weight reduces lateral soil pressure on the wall, its drainage properties prevent water building up behind the structure, and it eliminates the risk of soil settlement around foundations.

Argex (Leca) Clay Balls 50L

Description

What is Leca / Expanded Clay?

Leca (Lightweight Expanded Clay Aggregate), also sold as Argex, clay balls, clay pebbles or expanded clay, is a lightweight spherical aggregate made from natural clay fired at around 1,200°C. Each pellet has a ceramic foam interior with micropores and a rigid, sturdy outer shell. It conforms to BS EN 13285 and BS EN 13055 for lightweight aggregates. Bulk density is approximately 0.3 tonnes per m³, with the finer 0/2mm grade approximately 0.55 tonnes per m³.

What makes Leca special?

Leca is up to 80% lighter than traditional mineral aggregates while still offering impressive strength, thermal insulation and acoustic performance. It is pH neutral, inert, fireproof, rot-proof and completely reusable. Its porous ceramic structure provides excellent drainage and moisture regulation, making it one of the most versatile aggregates available for both construction and horticulture. All material conforms to BS EN 13055 for lightweight aggregates in concrete, mortar, grout and geotechnical applications.

Where to use Leca / Expanded Clay Balls?

Leca is ideal for lightweight concrete, lightweight screeds, floor levelling, insulating concrete blocks, flat and inclined roofs, green roof substrates, soil drainage, soakaways and geotechnical backfill behind retaining and basement walls. In horticulture, clay balls are the go-to medium for hydroponics, aquaponics, semi-hydro houseplants, orchid growing, pot drainage and decorative top dressing. Engineers specify it to reduce soil pressure around foundations and avoid settlement around structures.

Extra Information

Leca is quick drying and easy to apply - it can be poured, raked and levelled without specialist equipment. It is non-combustible, chemically inert and will not rot, harbour pests or support mould growth. Clay balls can be washed and reused indefinitely in hydroponic and houseplant systems. Sometimes referred to as Leca, Argex, Hydroleca, Hydro Clay, clay pebbles or expanded clay pellets - all names refer to the same product.

● BS EN 13055 compliant
● Lightweight - approx. 0.3 t/m³
● Excellent drainage & insulation
● pH neutral & reusable

There is a 1 tonne minimum delivery on this product. This material is supplied loose tipped, however for smaller quantities we can offer bulk bags and poly bags, and for larger quantities we can offer 29 tonne artic loads, 8 wheeler 20 tonne loads and 4 wheeler 11 tonne loads.

We deliver our Leca / Expanded Clay and other lightweight aggregates to Thatcham, Newbury, Reading and all the surrounding towns and villages around Berkshire, North Hampshire and Southern Oxfordshire.

We have over 40 years experience as aggregate suppliers. To get a quote please call 01635 865679. If you are a commercial gardener or landscaper we do offer trade discount.