How to Install a Stone Patio

If you are considering installing a stone patio, read this. The proper method involves a lot of work, but it is a straight forward process overall. A stone patio is a visually stunning addition to the exterior of the house and it is well worth the effort.

Things You'll Need

• Flagstone
• Concrete
• #4 Rebar
• 2x6 Form Boards
• Jumping Jack
• Gravel
• Dobies

Instructions

1. Clear out the shrubs and grass from the area you plan to build the patio; get down a clean layer of soil. Use a shovel and a rake to level out the soil. Pick up a couple of landscape magazines and review patio designs to get some ideas and figure what kind of stone you want to purchase.

2. 

   Rent a Jumping Jack, pictured left, to firmly compact the earth within the boundaries of your new patio location. This step is key to the performance of your patio over time. An uncompacted subgrade will allow settlement to occur over time, this will lead to cracked stone, fractured mortar joints and lifts in the patio stone that will catch your foot.

3. 

   Layout your patio with a string line and stakes. This process will enable you to create straight lines and square corners when you install your 2x6 form boards. Hammer three stakes into the ground about 3'-0" past the corner markers of the foundation. Each stake should be about 3'-0" away from the other creating a square corner. Screw a 1x4 piece of wood across the stakes, this is your batter board. Importantly, the batter boards don't need to be totally square themselves. The string line is the only component that is required to be square.

4. 

   Square up the lines using one of two proven formulas. First is the Hypotenuse Rule or 3-4-5 check, which states the hypotenuse should be 10'-0" when one leg is 6'-0" and one leg is 8'-0". Just measure back from one corner 6'-0" and mark the string, then measure the opposite string back 8'-0" and mark it. Finally, measure the diagonal between those two marks to the hypotenuse. You can also use the Diagonal Method in which you measure both diagonals as pictured and adjust your strings until both diagonals are exactly equal.

5. 

   Install the form boards. First, drive a few metal concrete stakes into the ground, right in front your string line. Next, hold the 2x6 against the stakes and screw the form boards to the stakes. It is best that you have two people involved in this process. Be sure to build a slope into your form boards, so that the water washes away from the house. Typically, a 1/4" per foot slope is used.

6. 

   Install 2" of gravel and then install #4 rebar in a grid. Space your rebar 12" to 18" apart and run the rebar the length and width of your patio, this will create the grid.

7. Pour the concrete. Reference my article in the upper left hand corner of the page "How to Lay Down Concrete". In this particular process, you only need to finish the concrete with a broom finish since it will be covered by stone. Your attention needs to be focused on creating a level concrete surface.

8. 

   Cutting the flagstone is the most difficult part of the process. You will need to make a lot of cuts and some curved cuts to get a pattern that fits together. This is not easy considering the piece of equipment used to do this work is a large, gas powered hand held saw pictured to the left. Be extremely careful when using this saw. Also, wear some serious ear and eye protection. The sound is deafening without ear protection.

9. 

   Time to begin installing the flagstone. You will need Portland Type I-II mortar to adhere the stone to the concrete. Mixing the mortar by hand in a wheel barrel is doable, but you can save yourself time by renting a mixer.

   Do a dry layout before cementing the stone into place to make sure the layout works. Then apply a thin layer to the back of the flag stone and some on the concrete slab where you plan to install the stone. Gently slide the stone into place.

10. 

    Press cement into the joints between the stones. Scrape the excess away with a trowel and then clean and smooth the joint with a large sponge. Clean the surface really well. There will be a film/haze left on the entire patio once you are done. It is recommended that you use 600 Detergent by Prosoco for a final clean. Wait for a couple of weeks, clean again and then seal the patio. Lastly, move in the patio furniture and patio heater.