Paver base calculator for Idaho

The stone beneath pavers costs several times less per square foot, but that lower layer is often where patio problems begin. Size it here as compacted crusher run or a similar blend at 1.5 tons per cubic yard: use 4 inches for foot traffic and 6-8 beneath cars. The +10% compaction allowance is on by default. Keep bedding sand separate as its own strict 1-inch layer and use its calculator.

Base sizing

1. Calculate the paved space in feet and carry the base 6 inches beyond each exposed paver side. That extension supports the edge restraint.
2. Use 4 inches of compacted base for patios and walkways. Allow 6 for driveways or clay soil, and 8 for driveways over soft ground.
3. For yards, divide cubic feet by 27; then x 1.5 for tons. Keep the +10% allowance on.

Project base depth and coverage

Excavation layers from turf to the finished paver

Figure the excavation from all layer thicknesses together. For a usual patio, allow 4 inches of base, 1 inch of bedding sand, and a 2 3/8 inch paver, finished even with the lawn. This calls for a 7.5-inch dig, adjusted for the reveal you plan to leave above grade. Put that depth on a stake and use it to check the hole as work continues. Going too deep adds disposal cost for removed soil and requires more stone to rebuild the level. Run the Dirt Calculator backward to find the yards coming out.

Paver base installation notes

• Build and compact in 2-inch lifts with a plate compactor, lightly misting each one. A damp base compacts tighter than a dry one.
• Shape the compacted base so it drops 2-3% away from the house. The bedding layer and pavers will follow that grade.
• Put edge restraint on the packed base, not on lawn soil. The 6-inch overhang gives it a place to sit.
• For clay ground, including parts of the Panhandle, place woven geotextile below the base. It keeps stone from working down into wet subgrade over time.
• Base thickness cannot be replaced by a deeper sand layer. Sand shifts, and patios can end up uneven.

Reusing base under old pavers

For an existing patio that needs pavers reset, the base may still be usable. Remove the pavers, clear away prior bedding sand, then check the base. If it remains level, firm, and drains properly, install a new 1-inch bedding layer instead, reducing the stone needed to a tenth of a full installation. Remove and rebuild the base if it has low areas, yielding spots, or pooled water. In the Palouse or Panhandle, retained moisture can make those checks especially important. Leaving a failed base in place puts the same problem beneath the replacement pavers.

Example: 16 x 12 patio

For 192 square feet of paving, add the 6-inch overhang on three exposed sides to get a 210 base area. At 4 inches compacted, calculate 210 x 0.333 = 70 cubic feet, or 2.6 cubic yards. That is about 3.9 tons and 4.3 with the allowance. Order 4.5 tons of crusher run and 0.9 tons of bedding sand from the Paver Sand Calculator in one free delivery. Schedule delivery after excavation, since a stone pile on the lawn for two weeks leaves a dead rectangle.

Questions about base depth, digging, and tonnage

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