Ballast & Hardcore
All-in ballast, hardcore and recycled sub-base — the fill and mix materials under groundworks.
Ballast and hardcore sit under everything. Ballast is a pre-blended sand-and-stone mix you add cement to; hardcore is coarse fill used to build ground up to level before the structural layers go on. They are cheap materials, and getting them right is what stops expensive things above them moving.
Sold by
Tonne, bulk bag (~850kg) or full load
All-in ballast
Typically 0–20mm blended sand and stone
Bulk density
~1.6–1.8 tonnes per m³
Concrete yield
~1 tonne ballast + 6 bags cement ≈ 0.5m³
Ballast & Hardcore on Loadbase
Delivered prices depend on the distance from the yard to your site, so they are quoted against your postcode rather than listed here.
See ballast & hardcore near youAll-in ballast
A ready-blended mix of sharp sand and gravel, usually 0–20mm, sold so you only need to add cement and water. It is the standard material for site-mixed concrete: footings, over-site slabs, shed bases, post setting and general oversite.
A common general-purpose mix is 1 part cement to 6 parts ballast by volume (roughly a C20 equivalent). For foundations and anything structural, work to a specified mix or order ready-mix instead — consistency between barrow-loads is where site-mixed concrete loses to a truck.
Hardcore and fill
Coarse, broken material used to raise levels and provide a stable platform: crushed concrete, brick rubble, scalpings and quarry waste. It fills volume cheaply and drains well.
Hardcore is not a finished sub-base. It is too coarse and too variable to compact to an even surface, so it is normally blinded with a layer of Type 1 or sand before anything is laid on it.
Watch what is in it. Recycled fill from a reputable yard is screened and consistent; unscreened demolition rubble can carry plaster, timber and soil that rot or swell.
Recycled sub-base
Crushed concrete graded to a Type 1 specification performs the same structural job as virgin quarried stone on most groundworks, usually at a lower price and with a much smaller carbon footprint.
For domestic drives, patios and paths it is generally the sensible default. Where a drawing specifies primary aggregate, it will say so.
Work out how much you need
Common questions
How much ballast do I need per cubic metre of concrete?
Roughly 1.8 to 2 tonnes of all-in ballast plus about 300kg of cement yields one cubic metre of general-purpose concrete. Ordering ready-mix is usually cheaper and more consistent above about 2m³.
What is the difference between ballast and hardcore?
Ballast is a graded sand-and-stone blend intended to be mixed with cement to make concrete. Hardcore is coarse fill used to build ground up to level; it is not mixed with cement and is not a finished surface.
Can I use hardcore under a concrete slab?
Yes, as the fill layer, but it must be compacted in layers and then blinded with sand or Type 1 so the slab bears on an even surface and the damp-proof membrane is not punctured.
Other materials
Trade guidance, not a specification. Always work to the product's Declaration of Performance and any drawing or engineer's specification for the job. Reviewed 2026-07-12.