Building a Sand Base

Intro

When not secured with mortar, patio and path paving--brick, flagstone, and precast pavers--must be set in a sand base over a gravel subbase. Sand provides a solid base for the pavers, and the gravel ensures good drainage.

Sand-set (sometimes called dry-laid) installations are much easier to build than mortared surfaces. They don't require specialized skills, and because there's no concrete required, they are less expensive. A properly bedded sand-set patio will last for years and require little or no maintenance.

Take your site measurements with you when you're ready to order the paving. Your dealer will help you convert those measurements to gravel, sand, and paving quantities. Remember to buy extra pavers to cover breakage and mistakes, and to store in case a paver or two needs replacing in the future.

Soil conditions will influence the construction of your project. Sandy soils drain very quickly but are soft. Clay is hard and doesn't drain well. Contact your extension office or building department for tips pertinent to your location.

Prestart Checklist

Time
About three days to lay out and excavate a 12x14-foot site

Tools
Round-nose shovel, tape measure, spade, mason's line, batter boards, carpenter's level, small sledgehammer, screed, garden hose

Skills
Measuring, leveling, laying out square lines

Prep
Plan site, choose materials, draw plans

Materials
Landscape fabric, edge restraints and spikes, gravel, sand, PVC pipe or 2-inch lumber strips

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Step 1

Lay out the site with batter boards and staked lines. Slope the lines to provide drainage, slice the soil at the perimeter, and remove the sod. Excavate the site for the thickness of your materials: typically 4-6 inches of gravel, 2 inches for a sand bed, plus the thickness of the pavers. Measure from the mason's lines for consistent depth. Shovel in the gravel or crushed stone base 3 inches at a time, spreading it evenly. Compact each layer until it reaches the proper thickness. A crushed rock base with an abundance of fine particles will compact firmly and create solid support.

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Step 2

Spread landscape fabric over the gravel--it will help kill the weeds and prevent the sand base from sifting into the gravel. Overlap the edges of the fabric by at least 6 inches. Install the edging around the perimeter, following the manufacturer's instructions. The easiest edge restraints to install are those with wide supports and closely spaced holes for the anchor spikes. Make sure you drive the spikes through the gravel into the soil.

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Step 3

Set 1-1/2-inch PVC pipe (or 2-inch boards ripped from 2x4s) on the landscape fabric, parallel with the edges of the excavation and at about 5-foot intervals. They provide a built-in depth gauge and screeding tool for the sand base. Shovel sand over the entire surface, dampen it, and tamp it. Then screed the sand level.

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Screed the Sand: Use a 2x4 to Level the Sand

Screed the sand to a consistent level by setting a long 2x4 on the edge forms and the PVC or wood inserts. Pull the screed across the surface in a seesaw motion--you'll need a helper for large areas. Then fill in depressions, dampen the sand, and tamp it. When the site is level, remove the pipes or boards, fill the recesses with sand, and tamp again.

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Sizing the Site Exactly

If patio or path dimensions equal multiples of tile or modular materials, you'll have less cutting to do at the edges. Save yourself time and effort by making the site dimensions the same as an even number of pavers. Lay out the paving in both directions on a flat surface, and measure the lengths. Then lay out your site to these dimensions.

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What If ... The Patio has Curves?

For curved patio edges, use plastic edging with notches in the outside flange. This material conforms to almost any arc. Drive spikes through the holes in the flanges, making sure they penetrate the soil below the gravel.

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