In tall buildings the structure's own dead weight is the greater part of what reaches the foundation. Replacing normal-weight aggregate reduces that load on every floor, and the effect accumulates all the way down.

In practice: smaller beam and column sections, less reinforcement, and — in refurbishment — the option of adding a storey without strengthening the existing foundation.

Mix design must be set out by volume rather than by weight, and the aggregate pre-soaked before batching.

A conventional pumice or site-mixed lightweight screed weighs 800–1,200 kg/m³. The same build-up in expanded clay weighs around 400.

Over a large roof that difference amounts to tens of tonnes of dead load removed, while producing a continuous layer of thermal insulation — no joints, no thermal bridges — across the slab.

On soft ground, adding embankment means adding settlement. At a fifth of the weight of soil, expanded clay builds the same height for a fifth of the load.

Behind a retaining wall it does two things at once: less lateral pressure because it weighs less, and no pore water pressure because it drains freely. Both feed straight back into wall thickness and reinforcement.

What limits any green roof is the slab's capacity when everything is saturated. A gravel drainage course is heavy wet; expanded clay at the same depth weighs a fraction of it.

At the same time the granule's porosity retains part of the rainfall and releases it between waterings — which cuts both irrigation demand and the peak load on urban stormwater drainage.

The granules are fired above 1,100 °C, which leaves a medium entirely free of weed seed, fungi and nematodes with no initial sterilisation.

Being chemically inert, it does not shift the EC or pH of the nutrient solution — decisive in hydroponics. At the end of a crop cycle the medium is washed, sterilised and used again.

Organic insulants lose performance with time and moisture, and add fire load in a blaze. Expanded clay does neither: fully mineral, Euroclass A1 reaction to fire, stable to about 1,150 °C.

Typical uses: filling cavity walls, insulating ground-bearing floors, packing around buried heating pipes, and lining industrial kilns and flues.

The granule's porous internal surface gives biofilm somewhere to establish, which is why it is used in trickling filters and constructed wetlands.

Being chemically inert and resistant to attrition, the bed lasts without the periodic replacement other media need.