Patio / paving (slabs on a mortar bed): calculator for UK builders
Answer the measurements this calculation needs and JobBosh works out the materials with wastage and pack rounding, the labour hours by role, the plant, the waste and the site needs - then prices them from your own figures, a supplier's quotation or a dated price you record. Free, no account needed to start.
What it works out
- Material: Concrete slabs 600; MOT type 1 (100-150 mm); Sharp sand + cement for the mortar bed; Jointing compound / mortar
- Plant: Plate compactor hire
- Labour: Dig out, hardcore, compact; Lay paving and joint
- Waste: Dig-out spoil (bulked)
The questions it asks
| Question | Unit / choices | Required? | Help |
|---|---|---|---|
| Paved area | m2 | required | |
| Paving | one of: concrete slabs 600, porcelain 600, indian sandstone, block paving | optional - default concrete_slabs_600 (labelled assumed) | |
| Dig-out depth | mm | optional - default 200 (labelled assumed) | |
| Edging length | m | optional - default 0 (labelled assumed) |
The norms behind it, with their sources
Coverage, productivity and wastage defaults you can edit; each carries where it comes from and is shown as assumed until your own benchmark replaces it.
| Norm | Value | Source | Tier |
|---|---|---|---|
| Dig out, hardcore, compact per m2 | 0.5 hr/m2 | trade practice | assumed |
| Lay slabs on full mortar bed per m2 | 0.9 hr/m2 | trade practice | assumed |
| Lay block paving per m2 incl. screed and compaction | 1.2 hr/m2 | trade practice | assumed |
| Mortar bed per m2 at ~40 mm | 80 kg/m2 | trade practice | assumed |
A worked example
Answers used: Paved area 20 m2; Paving concrete slabs 600; Dig-out depth 200 mm; Edging length 0 m. These are the recipe's own quantities for those answers - the prices are yours, the supplier's or a quotation's, never a figure typed on a web page.
| Kind | Line | Quantity | How it is worked out |
|---|---|---|---|
| material | Concrete slabs 600 | 21.4 m2 22 x m2 - per m2 / per pack | 20 m2 |
| material | MOT type 1 (100-150 mm) | 6.62 t 8 x bag - bulk bags | 20 m2 x 150 mm x 2.1 t/m3 |
| material | Sharp sand + cement for the mortar bed | 1600 kg 2 x bag - bulk bag sand (cement separately) | 20 m2 x 80 kg/m2 |
| material | Jointing compound / mortar | 20 m2 2 x pack - ~10 m2 per tub | 20 m2 |
| plant | Plate compactor hire | 1 hire-day | 1 day per ~30 m2 |
| labour | Dig out, hardcore, compact | 10 hr | 20 m2 x 0.5 h/m2 |
| labour | Lay paving and joint | 18 hr | 20 m2 x 0.9 h/m2 |
| waste | Dig-out spoil (bulked) | 5.2 m3 | 20 m2 x 200 mm x 1.3 |
Labour on this example: about 28 hours across the roles; at your rates it becomes money.
Site questions this work raises: Site access and neighbours, Waste, Parking and traffic, Utilities and welfare.
Specialists or hire it may need, drafted as enquiries from the job's facts: Grab lorry / muck-away, Materials (merchant) delivery.
Falls away from the house (1:60-1:80) and 150 mm below the DPC.
Then what
Price the lines from your crew rates and your material prices (each with its source and date), answer the site questions (parking, skip, welfare, power, water, protection), let JobBosh draft the supplier enquiries you approve, and issue a branded quotation your customer accepts on a secure link. Guest work is kept for 14 days; a free account keeps it for good.