How To Make a Flagstone Patio

Flagstones laid on sand and filled in with decomposed granite create a firm foundation for a great entertaining space.

Time
Weekend
Price Range
$500 - $1,000
Difficulty
Easy to Moderate

In this Project you will:

Clear and Define the Area
Excavate the Soil Two Inches
Install a Base Layer of Sand
Install the Flagstone
Fill in the Cracks
Water Down the Patio and Fill Again

Step 1: Clear and Define the Area

Remove any existing grass, pavers or debris to start on a clean surface of bare dirt. You don't want any vegetation in your new patio area because weeds could peak through if you don't clear them all. Draw the shape of your new patio with spray paint. Use a can with an inverted tip so you can spray upside down. This will define your space. If you don't like it, cover it with dirt and try again. Flagstone pieces are all different shapes and work best when using a natural border with curved edges instead of straight ones.

Step 2: Excavate the Soil Two Inches

Your flagstone patio should be even with your surrounding landscape once completed. Since the bare soil around this patio will be filled in with sod later, setting the flagstone two inches down will allow it to be level with the sod once it's installed. Once you excavate, grade the area as level as possible.

Step 3: Install a Base Layer of Sand

This flagstone patio will sit on top of sand. Use a "washed sand" for this, as it won't hold on to a lot of water. You can purchase it in bulk from a soil yard. Sand works well for a flagstone base because it settles in to slightly uneven surfaces on the ground as well as the uneven flagstone, supporting it from all sides.

Step 4: Install the Flagstone

Flagstone comes in several colors including shades of red, blue, tan and brown. There are several different methods of installing it but it's basically like assembling a big, heavy puzzle. Use your largest pieces in areas with the most foot traffic and places where furniture will sit. Place the stones one to two inches apart on all sides, depending on the look you're going for, keeping the gap sizes consistent throughout. As you set each stone in the sand, wiggle it around to make sure the sand completely covers the bottom of the stone on all sides.

Step 5: Fill in the Cracks

Decomposed granite is a crushed rock material usually found in a tan color. Use a bucket to pour it into the gaps between the flagstone pieces. This will lock the pieces together, creating your solid patio space. As you pour, push the decomposed granite into place, getting rid of any air gaps. Use a broom to sweep any excess into the gaps.

Step 6: Water Down the Patio and Fill Again

Use a hose to lightly water down the entire patio. This will cause the decomposed granite to settle in and lock into place. Keep repeating the last two steps until the decomposed granite is flush with the flagstone.