Garden Surveyor
Worked example
An 8.0 m × 4.0 m block paved driveway, herringbone, on a 150 mm sub-base.
Inputs
- Surface
- Block paving
- Area
- 8.0 m × 4.0 m
- Laying pattern
- Herringbone
- Sub-base depth
- 150 mm
| Step | Working | Result |
|---|---|---|
| Area | 8.0 m × 4.0 m | 32 m² |
| Total allowance | wastage plus herringbone cutting allowance | 18 % |
| Blocks | 32 m² × 50 blocks/m², plus the allowance | 1,888 |
| Sub-base | 32 m² × 0.15 m, compacted, at 2.1 t/m³ | 13.86 t |
| Laying course | 32 m² × 0.05 m of sharp sand | 2.56 t |
| Excavation | 32 m² × 0.25 m dig | 8.32 m³ |
| What to order | Quantity |
|---|---|
| Blocks required | 1,888 |
| MOT Type 1 (order qty incl. 10%) | 13.86 t |
| Screed (laying) sand | 2.56 t |
| Kiln-dried jointing sand | 64 kg |
| Edge restraint length | 24 m |
| Spoil tonnes | 13.31 t |
In short: Order 1,888 blocks, 13.86 t of MOT Type 1, 2.56 t of screed sand and 64 kg of kiln-dried jointing sand, and allow for 13.31 t of spoil off site.
How to work out block paving materials
A standard 200 × 100 mm block gives 50 blocks per square metre, so multiply your area by 50 and add about 5% for cuts. Underneath, a driveway needs 150 mm of compacted MOT Type 1 with a 30–40 mm sharp sand laying course. The calculator above sizes blocks, sub-base, sand and edging together so the full build-up is covered in one order.
Block paving build-up (UK)
| Layer | Guide |
|---|---|
| Blocks per m² (200 × 100 mm) | 50 blocks |
| Sub-base: driveway | 150 mm compacted |
| Sub-base: path / patio | 100 mm compacted |
| Sharp sand laying course | 30–40 mm |
Restrain every edge with edging kerbs or a concrete haunch, brush kiln-dried sand into the joints, and consider permeable build-ups to avoid draining to the highway.
Pricing a full driveway job?
Set out levels and falls, take off every material and build a compliance-aware quote.
Frequently asked questions
- How many block pavers do I need per m²?
- A standard 200 × 100 mm block gives 50 blocks per square metre. Multiply your area by 50 and add about 5% for cuts and breakages. The calculator above does this and also sizes the sub-base, laying sand and edging.
- What sub-base depth for a block paving driveway?
- For a domestic driveway, lay 150 mm of compacted MOT Type 1 sub-base, topped with a 30–40 mm sharp sand laying course. Paths and patios can use 100 mm of sub-base. Poor ground may need extra depth and a geotextile membrane.
- How much sand for block paving?
- Allow a 30–40 mm sharp sand laying course screeded level over the sub-base, plus kiln-dried sand brushed into the joints at the end. The calculator estimates both from your area.
- Do I need edging for block paving?
- Yes, block paving must be restrained at every edge with edging kerbs or a concrete haunch, or the blocks will creep and spread under load. Plan edging along all unrestrained perimeters.
- Does a block paving driveway need planning permission?
- A permeable driveway, or one that drains to a lawn or border rather than the road, usually doesn't need planning permission. An impermeable surface over 5 m² draining to the highway may need it, check current SuDS guidance for your area.
Link to this tool
Found this useful on your site, blog or forum post? Copy the snippet below.
<a href="https://gardensurveyor.com/block-paving-calculator">Block paving calculator: blocks, sand and sub-base</a>