Work out the blocks, Type 1, sharp sand, kiln-dried jointing sand, edging and skip for a block paved driveway or patio.
150mm recommended for vehicle traffic
Screeded sharp sand bed, no cement (depth before compaction)
Area × Type 1 depth (150mm by default for vehicles) × 2,100 kg/m³ compacted, plus your waste allowance, rounded up to whole bulk bags.
Blocks sit on a screeded sharp sand bed with no cement, usually 30–50mm deep before compaction. Area × depth × 1,600 kg/m³ gives the sand.
Each block covers its own size plus a 3mm joint, so a 200 × 100mm block works out at about 48 per m². We add the pattern's cutting waste (herringbone at 45° needs the most cuts) and your general waste, and round up.
Kiln-dried sand at about one 25 kg bag per 5 m². Edge restraint runs round the perimeter, held by a concrete haunch of about 0.03 m³ per metre, mixed 1:6 with all-in ballast.
The dig covers Type 1 + sand + block thickness. The skip is chosen by the volume of loosened soil and its weight.
These are estimates for ordering materials, not a structural design. Check site conditions, and anything unusual, with a qualified builder or engineer.
150mm of compacted Type 1 for a domestic driveway. 100mm is usually enough for a patio or path that only takes foot traffic. On soft clay go deeper, or add a geotextile membrane.
About 50 standard 200 × 100mm blocks per m², or 48 once 3mm joints are allowed for. Add 5% for stretcher bond and 10–15% for herringbone.
Blocks are held in place by friction with their neighbours. Without a solid edge, either kerbs or a row of blocks set on end in concrete, they slowly spread outwards and the joints open up.
The main area should go on sharp sand so it can flex and drain. Mortar or concrete is used only under the edge course.
Roughly one 25 kg bag per 5 m² for the first fill. Joints settle over the first few weeks, so keep a bag back to top them up.