How many pavers for a 20x20 patio?
A 20x20 patio needs 1890 standard pavers (4 x 8 in).
That is 400 sq ft, including 5% for cuts and breakage.
By paver size
| Paver size | Pavers needed |
|---|---|
| 4 x 8 in | 1,890 |
| 6 x 6 in | 1,680 |
| 12 x 12 in | 420 |
Counts include 5% for cuts. Running bond and stack bond waste about that much; a 45° herringbone cuts every paver along both edges and wants 10%.
Where that number comes from
- 20 ft × 20 ft = 400 sq ft
- A 4 x 8 in paver covers 32 sq in = 0.2222 sq ft
- 400 ÷ 0.2222 = 1,800 pavers
- Add 5% for cuts and breakage = 1890 pavers
Change the numbers
What goes underneath
- Compacted gravel base, 4 in: about 4.94 cubic yards.
- Bedding sand, 1 in: about 1.23 cubic yards. Coarse sand, not play sand.
- Edge restraint: around 80 linear feet to go round the perimeter.
- Polymeric sand to sweep into the joints once it is laid and compacted.
The base is the patio. Pavers laid on thin or uncompacted gravel will rut and settle within a season no matter how carefully they were placed.
Getting it right
- No edge restraint. Without it the perimeter creeps outward and the joints open up. It is the cheapest part of the job and the one that holds it together.
- Skimping on base depth. Four inches for foot traffic, more over soft or clay soil, and compact it in lifts rather than all at once.
- No slope. Fall about 1/4 in per foot away from the house or water will find the low corner and sit there.
- Buying exact. Colour varies between production batches. Buying short means the replacements will not match.