How to Excavate for a Patio

How to Excavate for a Patio

Excavation simply means digging. Use the right tools to make the job as efficient as possible. A garden edger quickly cuts a straight line through sod. A shovel with a curved blade is for digging; don't confuse it with a spade, which has a flat back and is designed to cut the edge of a trench.

To remove sod, break up the surface with a mattock, which looks like a pick. If your patio is large, you might want to use a sod lifter, which has a curved handle and will save you much bending.

The depth you dig depends on the type of patio: 8 to 9 inches for bricks or pavers set on a sand-and-gravel base, 8 to 9 inches for a concrete slab patio, and 11 to 12 inches for bricks or stones set in mortar on a concrete slab.

When excavating, make sure you dig out all roots and organic material, which tend to decay, collapse, and undermine your patio.

Skill Level: Intermediate
Time:
  1. Step 1 Lay Out the Shape

    Lay Out the Shape

    Set up batterboards and use mason’s line to lay out the outline of the patio or walkway. Use powdered chalk to mark the outline.

  2. Step 2 Step on the Edger to Cut Straight Into the Sod

    Step on the Edger to Cut Straight Into the Sod
    Step on the Edger to Cut Straight Into the Sod

    Work your way along the layout lines. To remove wide areas of sod, cut 1-foot strips with the edger. Lift the sod with a shovel or sod remover. Hold the blade at a low angle. Put weight on the top of the tool to cut between the soil and the roots and pry it loose.

    Roll the sod and remove it from the area to be excavated. Put at least some of it in a cool, shady place and use it to patch the lawn when you finish the project.

  3. Step 3 Dig a Trench

    Dig a Trench
    Dig a Trench

    Work along the layout lines, measuring down from them to dig a trench to the desired depth of the excavation. Usually the excavation slopes as it runs away from the house and is level from side to side.

    The directions for individual projects state the proper slope. Dig the trenches at the recommended slope. Rest a level on a straightedge and check to see if the trench is level. If the excavation is supposed to slope for drainage, put a wedge between the straightedge and the level equal to the desired slope over the length of the level.

  4. Step 4 Dig Between the Trenches

    Dig Between the Trenches

    Large excavations, such as those for patios, will have a grid of layout lines, and you should dig a properly sloped trench under each one. Once you have, dig out the space between the trenches. Smooth by pulling a 2x4 along the surface and check with a level. Regrade as needed and compact.

What You Need for This Project

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