A paver patio is three orders and a hole: the pavers, the crushed stone they sit on and the inch of sand they are bedded in. This page works out all of it from the size of the patio and the size of the paver, with the figures the paving industry builds to:
- Joints of 1/16 to 3/16 inch (2 to 5 mm), from the Interlocking Concrete Pavement Institute’s Tech Spec 2. Each paver takes up its own size and a joint, which is why a 4 × 8 inch paver lays about 4.3 to the square foot at an eighth-inch joint, not the 4.5 its face alone suggests.
- A base of 4 inches under a patio or path and 6 under a driveway, measured after compaction on well-drained soil — and 2 to 4 inches more in a cold climate or on wet or weak soil, ICPI says. The base is bought loose and rolled down, so the page orders it the way Penn State’s road handbook lays it, 8 inches loose for 6 finished, and weighs it at the gravel calculator’s figure.
- An inch of bedding sand, screeded and left uncompacted.
- 5 per cent extra pavers, always, for the ones cut to fit, and 10 when you know a lot will be cut, as Oregon State’s installation guide puts it.
How deep to dig is the base, the sand and the paver’s thickness added together — Oregon State’s rule — and the edge restraint runs round the outside, which the page measures when you give it the two sides.
Measured the patio on the calculator? Follow its link here and the area comes with it. For a poured slab instead of pavers, the concrete calculator takes the same measurements.