Standard jointing and bedding sand conventions
| Item | Typical convention |
|---|---|
| Jointing sand | ≈4.5 kg per m² (varies with joint width and sand type) |
| Bedding sand depth | ≈30 mm (0.03 m³ per m²) — a common residential starting depth |
| Joint gap | Commonly 2–5 mm for concrete pavers; check manufacturer spacing lugs/recommendation |
- Jointing sand consumption and bedding sand depth are commonly used estimating conventions; actual requirements depend on the specific paver system, joint width, sand type (including polymeric jointing sand), and the base preparation specified by the manufacturer or a landscaping/hardscaping professional.
- This calculator does not estimate the sub-base (crushed stone/gravel) layer beneath the bedding sand, which is a separate structural component sized for the expected traffic load (pedestrian vs. vehicular) and local soil/frost conditions.
What does a paver calculator do?
A paver calculator estimates how many individual pavers are needed to cover a given area, based on the paver's length and width and the joint gap left between units for jointing sand. It also estimates the jointing sand (swept into the gaps between pavers) and bedding sand (the leveling layer pavers are laid on) needed for the job, using standard hardscaping trade coverage conventions.
Each paver effectively occupies a slightly larger 'cell' than its own footprint once the joint gap is included, because the gap is shared between adjacent units. Bedding sand is estimated as a layer of a conventional 30 mm depth spread evenly under the paved area — a commonly used starting depth in residential paver installation, though local practice and the specific paver/base system can call for a different bedding depth.
How to use this paver calculator
- Enter the total area to be paved, in square meters.
- Enter the paver's length and width, in millimeters, as specified by the manufacturer.
- Enter the joint gap — the spacing left between pavers for jointing sand, in millimeters (commonly 2–5 mm for many concrete pavers).
- Enter a waste allowance for cutting at edges and borders, and read the estimated pavers, jointing sand and bedding sand needed.
The formula behind paver quantity
Each paver's effective footprint (its 'cell area') equals (paver length + joint gap) × (paver width + joint gap), converted to square meters. The number of pavers equals the paved area, increased by the waste allowance, divided by this cell area, rounded up. Jointing sand is estimated at 4.5 kg per square meter of paved area, and bedding sand at a 30 mm depth, equal to 0.03 cubic meters per square meter of paved area.
Worked example: a 20 m² area using 200 mm × 100 mm pavers with a 3 mm joint gap has a cell area of (0.203 × 0.103) ≈ 0.0209 m². With a 10% waste allowance, pavers needed = ⌈20 × 1.10 ÷ 0.0209⌉ ≈ 1,053 pavers. Jointing sand is estimated at 20 × 4.5 = 90 kg, and bedding sand at 20 × 0.03 = 0.6 m³.
Common mistakes
- Forgetting to include the joint gap in the paver footprint calculation, which understates the number of pavers needed.
- Using a bedding sand depth that doesn't match the specific paver system or base design being installed.
- Skipping a proper compacted sub-base layer, which this calculator does not estimate, leading to settling or shifting under load.
- Not adding enough waste allowance for cutting pavers at borders, curves or irregular edges.
Questions fréquentes
How many pavers do I need for 20 m²?
It depends on paver size and joint gap. Using 200 mm × 100 mm pavers with a 3 mm joint and a 10% waste allowance, 20 m² needs roughly 1,050 pavers — larger pavers need fewer units for the same area.
How much jointing sand do I need for pavers?
A common estimating convention is about 4.5 kg of jointing sand per square meter of paved area, though actual consumption varies with joint width and the type of sand (including polymeric sand) used.
How deep should the bedding sand layer be for pavers?
A commonly used starting depth for residential paver bedding sand is about 30 mm (0.03 m³ per m² of paved area), though the specific paver system, base design and local practice can call for a different depth.
Does this calculator include the sub-base layer for pavers?
No — it estimates pavers, jointing sand and bedding sand only. The compacted gravel/crushed-stone sub-base beneath the bedding sand is a separate structural layer, sized for expected traffic load and local soil and frost conditions.
What joint gap should I use between pavers?
Many concrete pavers are manufactured with built-in spacing lugs or a manufacturer-recommended gap, commonly in the range of 2–5 mm; check the specific product's installation instructions rather than assuming a fixed value.
Références
- Interlocking Concrete Pavement Institute (ICPI) — standard installation guidance for jointing sand, bedding sand depth and paver installation conventions.
- Manufacturer paver data sheets — paver dimensions, recommended joint gap and jointing sand type vary by product.
- General landscaping/hardscaping trade convention for bedding sand depth and coverage estimating.