Remove the existing grass. You can use a sod cutter for this task. The advantages of a sod cutter are: they cut evenly across the lawn, they are much less destructive to existing water lines and irrigation and you can roll it up and dispose of it which saves time.
Excavate to an average depth of at least two inches. While you can get away with less, you won't get as good drainage which can be especially important if your turf will be coming in contact with pets and their associated byproducts。
Cap any existing irrigation heads. Alternatively you can reconfigure them to "spritz" the turf and keep the irrigation system. This works well for really hot days to cool the turf or for pet owners who want to wash the turf down automatically.
Add gravel. Quarter inch self compacting gravel is recommended. Large gravel - half inch or above - will make getting a nice grade very difficult. Add gravel so it comes about a quarter inch above the bendaboard and is higher in the middle. If your area is a 20' by 20' square, it's best to make the middle of your install one inch higher than the edges. This will create a nice "mound" look.
Rake and compact. Rake using a 36" aluminum grading rake. This rake has teeth on one side and the back has a flat grading blade. Rake out the low spots as best as possible. Using a vibrating plate compactor, wet the area moderately with a hose and go over the area from outside in one time.
Wet the area down again. It should be pretty wet at this point, not flooded but as though it had rained heavily for about ten minutes.
Go over it again with the plate compactor. At the end you will have little lines from the edge of the plate compactor. Work these out with the flat edge of your rake. You will also have gravel shifting upwards at your edges where the plate compactor pushed the gravel up by the bendaboard.You may need a fine broom to remove the excess from the lines and excess material on the edges.
Add the synthetic turf. There are a few things to know here. The turf usually comes in 15 foot (4.6 m) widths and you always want to seam width wise. It is much harder to seam lengths together.
· If your area is 20 feet (6.1 m) by 20 feet (6.1 m), for example, you will need one fifteen foot wide section that is twenty feet long, and a second section that is 5 feet (1.5 m) wide and twenty feet long. Unfortunately the remaining ten foot wide by twenty feet long section would be an unused remnant. Unroll the first section, laying it close to the edge and leaving a few inches to spare in front and back lengthwise. For example if your area is 20x20 cut a strip about 20'6" long. Lay out your next section of 5' wide and 20' long.
Make preliminary cuts. Before cutting too close around the edges, cut out the excess factory material from the sides. We cut the third stitch in. Once you have cut stitches out you now know you have two straight edges that can be put together for your seam.
Make your seam. You have a few options. You can glue your seam or you can use staples or nails. Using glue and professional seaming tape is recommended. This gives a seam that is hard to detect and allows you to not have nails in the field. This is important for playgrounds as well as the stretching process.
To do the seam get the two turf pieces next to each other, emulating the distance between them which duplicates the stitching in the turf. What this means is if the stitches are 3/8" apart, you should pull the two turf pieces together until the stitches are 3/8" apart. If you are too far it will look empty. Too far is better than too close though.
Once you get your spacing right and the seam looks good, put some nails about 18" away from your seam. Just a few nails partially in every few feet will do. The nails are just to keep your turf from shifting at all.
· Now pull back each piece of turf leaving a couple feet of gravel exposed. Lay out your seaming tape (the tape should be 12" wide). Spread your glue over your seaming tape and trowel out so it covers the tape evenly but thinly.
· Let sit for about ten minutes to get tacky. Put the turf back down over the seaming tape, being careful not to let the blades get stuck in the glue. Put bags of sand or similar over the entire seam to make sure it doesn't shift.
Remove the bags or sand or similar, once your seam is cured (which may be the next day). You are now ready to stretch the turf. For most installs, you can stretch lengthwise only and don't need to stretch width wise. If the area is under 400sqft, you can get away with stretching from one side only.
· To do this, pull the turf so it lines up well with the bottom or top of your install then fasten the turf to your bendaboard or nail the turf down using your six inch nails.
· Using your feet, kick out the turf from the nailed side, trying to get out any wrinkles. Put six inch nails halfway in every 3 feet (0.9 m) out and 5 feet (1.5 m) wide so you don't lose your stretch. Keep stretching and nailing until you get to the other side.
· Once you get to the other side you can make your final cuts by the edge or bendaboard and use your screws or nails to fasten the turf. You can make your final cuts and fasten the sides at this time as well. Once you have nailed or screwed down the perimeter you can remove all the nails in the field.
Infill. Your last step is applying the infill. Infill helps keep your blades upright, gives the turf a more realistic look and helps keep your turf cool. For infill choices you have silica sand (cleaned beach sand, basically), Durafill (acrylic coated sand, usually green in color), crumb rubber (provides some fall rating but some have reported it can be a bit toxic), and deodorizing infills for pets (a good example is Zeofill). For most purposes sand is fine. If you have a lot of dogs we recommend a product like Zeofill to reduce odors).
·To apply the infill, use a power-broom (or a lot of power and a heavy duty push-broom) and make the blades stand upright. Then use a drop spreader or carefully use a flat shovel and apply the infill to the turf at a rate of 1.5 lbs/sqft. After applying brush again until the sand or other infill is evenly distributed. If your turf has a dusty look at this point just hose it down and you are done!