Before deciding to install a sprinkler, you must ask yourself if the expense is worth it compared to how often you might use it. In other words, if you occasionally water your lawn, then a permanent sprinkler system is probably not for you. On the other hand, if you live in a hot and dry area, then the benefits can be worth it if it means having a healthy lawn. You can hire a professional to install it for you, or install it yourself. You’ll need to find a local supply store for the necessary parts, and have a basic understanding of plumbing, electricity and local building codes. It is important that you call your local water supplier and talk to them about required permits and backflow prevention.
Draw your property
Use a tape measure to measure your property, including your house and all stationery objects, and then accurately sketch a scaled drawing of your lawn. Include in the drawing such items as water supply lines, driveway, sidewalks, trees, shrubs, garden beds, mailboxes and light posts. Next, determine where power lines and cable feeds are located underground, and indicate those on your drawing (you will have to call your local power supplier and cable company). On your drawing, mark the areas of your lawn where there are slopes, and also mark areas that are full sun and heavy shade.
Determine flow rate
Determine the flow rate of your water system. A simple method involves taking a five gallon bucket and timing how long it takes to fill the bucket with your spigot open all the way to full. Then, convert the rate to gallons per minute (GPM) by dividing the rate by 5 gallons and then multiplying it by 60 seconds to get a final GPM rate. For example, if it takes 25 seconds to fill the bucket, then the rate is 1 gallon per 5 seconds, or 12 GPM.
Finish the drawing
You need to place a sprinkler in each corner of the yard, and along the sides. The sprinkler’s output should overlap to ensure proper watering. A typical radius that a sprinkler covers is approximately 10-15 feet, so be sure and place the sprinklers no more than 15 feet apart. Keep in mind that corner sprinklers will cover 1/4 of a circle, while a side sprinkler will cover 1/2 of a circle. You can use a compass tool to draw circles on drawing showing the area that each sprinkler will spray water.
Next, determine on your drawing how many sprinklers you will need to ensure adequate coverage for the middle areas of the lawn, and where they should be located. Also determine locations for sprinklers for landscape beds so that they receive adequate water as well. You may need to purchase different sprinklers for these areas.
Select the items needed for your system
Now that you have your lawn mapped out, and an idea of where you need to place your sprinklers, you can determine what you need to purchase to build and install your system. There are various sprinkler types available for purchase, and each covers a different area depending on its design and your property’s water pressure. Determine how many sprinklers you will need for your yard, and the length of piping to put the system together.
In addition to the sprinklers and piping, you will need valves, pipe fittings, a backflow valve, caps and a timer (optional). Take your drawing to a local hardware store that sells these supplies and talk with them to determine exactly what you should purchase.
Prepare for installation
Call the local utilities, if you haven’t already done so, and have them mark any buried lines or cables in your property. Next, use your drawing and a tape measure and place flags where each sprinkler will be located. With marking paint, mark lines in the lawn where you will need to dig the trench to install the pipe.
Set up the water line
Tap into the local water supply line to your house. A representative from your water supply utility should be able to show you where you can tap into the line and how to set it up according to local codes.
Install the system
Using a trencher or a shovel, dig all the trenches needed to install the piping. How deep you install the pipe depends on your geographic location and local codes (check with the water utility and local professionals). Remember to pay attention to the areas that are marked for underground cables or wires. Assemble all of the pipes and shut off valves above ground prior to laying it in the trenches and attaching the sprinkler heads. After all the connections have been made, run water through the pipes to clean out debris and check for any leaks. Hook up the sprinklers and check the system again for proper water flow and leakage.
Finish the system
Bury the system in the trenches and place gravel beneath the sprinkler heads to improve drainage around them. Replace the sod and give it a good watering to keep it from drying out. Turn on the system and check the coverage and make adjustments as necessary. If you purchased a timer, install it according to the manufacturer’s directions, or hire an electrician to do it for you.