Do It Yourself: Flagstone Patio Installation

Laying a flagstone patio will add value and beauty to a home and is a do it yourself project.

Building a Flagstone Patio can add beauty, charm and often increase the resale value of a home. The homeowner can accomplish this addition to the home with the correct materials, tools and a little physical labor.

The tools needed for this project are the flagstone, sand, chipping hammer, pick, and shovel, ruler, rubber mallet, string line, level, broom, concrete, and AB3 sand and gravel.

Figuring the amount of stone needed will depend on the size and shape of the patio you are building. The square footage of the patio must be determined after mapping out the area for the patio. This square footage is necessary when purchasing flagstone, sand and gravel. Another decision to make will be whether to build the patio using the wet method or the dry method. The wet method is when the stone is set in a grout bed on a concrete slab and the dry method is when the stone is set in a sand base on the existing ground.

Construction of the patio begins with laying out the size and shape of the patio with string line and stakes. After the lay out is complete, dig the area to a depth of 6". This dug out area should be level. If the area is level, the remainder of the work left to do will be much easier. Once the area is level, wet it down, then begin the dry method by placing 3" of AB3 sand and gravel on it. Compact the area thoroughly.

After compaction is complete, fill the area with 1" to 1 ½" of sand. Begin laying the flagstone in one corner and put into place by using a rubber mallet to tap it. Level the stones by placing a straight board across the edge of the stones then add or subtract sand. Once again, use the rubber mallet to tap the flagstone into place. Using tight joints and large pieces of flagstone will minimize movement and add to the attractiveness of the patio.

The wet method of construction is more expensive than the dry method, but provides for a more permanent, maintenance free patio. For this method, the layout and excavation is the same as the dry method. After layout and excavation is complete, forms are set around the perimeter with the top of the forms where the finished patio will be. The forms should be set so that the patio will drain using a pitch of ¼" per foot. Now place gravel in the excavated area moving out 6" from the form boards. Place reinforcing mesh wire over the gravel. The patio is now ready for the concrete pour. The concrete to use is one part concrete, two parts sand and three parts gravel. Pour the concrete to within 2" from the top of the framework. Use a rake, spread the concrete, and pull the reinforced wire up so it rests on top of the concrete. Do not smooth the concrete because a rough surface is needed to apply the grout. Let the slab harden at least 24 hours.

After the slab has set for 24 hours, it is time to begin the next step, which is to lay the grout. Mix the grout, consisting of one part concrete, three parts sand and mixed with water, to a consistency of a snowball. Spread this over the concrete about 1" thick. Then lay each stone and tamp level with a rubber mallet. Spread only enough grout for one or two stones at a time. Be sure to level each stone by using a straight board placed across the framework. After laying a dozen or so stones, pick each one up and pour concrete butter over the grout, then set the stone back in place. The butter consists of concrete and water mixed in a bucket to the consistency of pea soup. This butter attaches the dry stone to the almost dry grout to cause a strong bond. Do not fill the joints until all the flagstones have been laid and the patio has been allowed to set at least overnight. The joints are filled with a mixture of one part concrete and two parts sand to a consistency of a little wetter than the setting bed. Use a pointing tool to pack the joints tightly. Do not smear the concrete over the flagstone. If concrete does get on the flagstone, wash it off immediately using a sponge and water.

To complete this project, dig a trench 6" wide x 6" deep around the patio and fill with concrete. Before concrete sets, trough a 45 degree bevel and cover with dirt. Sweep sand into the joints and wet thoroughly to finish the project.

© High Speed Ventures 2011