Category 04 · Basalt Setts
Black basalt setts & cobbles, wholesale to the UK trade.
Karpat supplies black basalt setts and cobbles to UK stone merchants, builders' merchants and landscape suppliers — natural split (cropped) cubes and setts in the sizes the trade lays, bought direct from the quarry in Turkey and delivered duty-paid to your yard by the container. Basalt is dark charcoal grey when dry and close to black when wet, and it is one of the densest, least absorbent paving stones there is: the reason it goes down on driveways, courtyards and conservation streets that have to take traffic and frost for decades.
Product 01
Cropped setts & cobbles
Cubes and setts with a natural split (cropped) top and split sides, in seven standard sizes from 50 mm cobbles to 160 mm cubes. A cropped face gives the textured, slightly irregular surface a courtyard or a conservation street needs, and it keeps its grip in the wet.
Applications
Driveways, courtyards & edging
The shallow sizes — 50 mm cobbles and 100 × 100 × 50 mm setts — are for patios, paths, edging courses and borders. The 100 mm-deep setts and cubes are the usual choice for driveways and anywhere a vehicle crosses, and the 160 mm cube for heavy-duty and heritage work. Black basalt also frames lighter paving: a single course of 100 × 100 setts is a standard edge to a buff sandstone or grey porcelain patio.
Packing
Bulk bags on pallets, or crated
Supplied as standard in one-tonne bulk bags on pallets, forklift-handled straight off the lorry with no hand unloading. Timber crates are available on request for yards that stack or sell by the crate. Mixed loads across sizes are normal: tell us which sizes you sell most and we build the container around them.
Sizes & container yields
Seven sizes, one 26-tonne box.
Basalt is bought by the tonne and laid by the m², so the depth of the sett decides how much ground a container covers. A 20ft container carries about 26 tonnes, and the coverage below is calculated at a 10 mm joint.
| Size (mm) | Weight per m² | Coverage per 20ft |
|---|---|---|
| 50 × 50 × 50 cobble | 92 kg | ≈ 283 m² |
| 100 × 100 × 50 sett | 110 kg | ≈ 237 m² |
| 70 × 70 × 70 cube | 142 kg | ≈ 183 m² |
| 100 × 100 × 100 cube | 219 kg | ≈ 119 m² |
| 200 × 100 × 100 sett | 229 kg | ≈ 113 m² |
| 170 × 170 × 100 sett | 236 kg | ≈ 110 m² |
| 160 × 160 × 160 cube | 376 kg | ≈ 69 m² |
We quote per m², delivered to your yard, for the mix of sizes you actually want.
The stone, tested
A true basalt, with the numbers to show it.
Petrographic analysis confirms the stone as a true basalt — a porphyritic volcanic rock of plagioclase and pyroxene — not a dark granite or dolerite sold under a basalt name. The physical results come from MTA, the General Directorate of Mineral Research and Exploration of the Republic of Türkiye, tested in a TÜRKAK-accredited laboratory (TS EN ISO/IEC 17025).
| Compressive strength | 244 MPa (TS EN 1926) |
| Compressive strength after freeze-thaw | 249 MPa — no loss |
| Mass loss after freeze-thaw | 0.0 % |
| Water absorption | 0.1 % by mass (TS EN 13755) |
| Böhme abrasion | 5.3 cm³ / 50 cm² |
| Apparent density | 2,650 kg/m³ (TS EN 1936) |
| Open porosity | 0.2 % |
| Flexural strength | 32 MPa |
| Hardness | 7 Mohs |
Low water absorption is what protects a paving stone from frost: water that never gets in cannot freeze and split it. These are the quarry's laboratory results (MTA reports, 2015 and 2008) — a technical data sheet, not a Declaration of Performance. Where a project is specified to BS EN 1342, we arrange the assessment and the DoP for that order.
How we source
Quarry-direct, samples first.
We buy from the quarry, not from a stockist, and we state the origin — Turkey — on every quotation. Send the sizes, finish and quantity; we return a delivered-UK price for the container, send samples ahead of order confirmation, and deliver duty-paid in GBP to your yard, or supply FOB/CFR for buyers running their own forwarders. Natural stone carries 0% import duty into the UK.
Sandstone walling & paving → · 20 mm outdoor porcelain paving → · Trade terms & documentation →
Common questions
Basalt setts — what UK buyers ask.
What is the difference between setts and cobbles?
Strictly, cobbles are naturally rounded stones and setts are quarried, roughly rectangular blocks with a flat top. In the trade today the words overlap: small cropped cubes, like our 50 mm size, are usually sold as cobbles, and the larger rectangular sizes as setts.
Is basalt better than granite for setts?
Both are hard igneous stones that take traffic well. Basalt is finer-grained, darker and less absorbent — this stone tests at 0.1% water absorption — so it stays close to black when wet and gives frost almost nothing to work on. Granite offers a wider colour range. A listing for "black basalt granite" describes one stone or the other, not both; ours is petrographically confirmed basalt.
Are black basalt setts frost-resistant?
Yes. In laboratory freeze-thaw testing this stone lost 0.0% of its mass and none of its compressive strength, and with water absorption of 0.1% there is almost no water in the stone to freeze.
What is the minimum order?
A full 20ft container — about 26 tonnes — which can be mixed across sizes. We deliver to your yard; unloading is your side, and the standard bulk-bag packing is forklift-handled.
Can we see samples first?
Yes. Samples go out before the order is confirmed, so the colour and the cropping are approved on the stone rather than on a photograph.
Quote on basalt setts.
Tell us the sizes you sell most and the quantity. We build the load around them and come back with a delivered price.
Request a basalt quote →