Installing an underground sprinkler system in your yard allows you to efficiently water your grass and landscaping. While hiring a professional is an option, you can save significantly by doing it yourself. With proper planning and some work, you can have a high-quality underground sprinkler system tailored to your yard.
Selecting the Sprinkler System Components
The first step is deciding which components you'll need for your underground sprinkler system. The main elements are:
This piping runs underground from your water source to the sprinklers. PVC is the most common material since it's affordable and easy to work with. The piping size depends on factors like yard size and water pressure.
These attach to the piping and distribute water to your yard. Consider spray heads for large open areas and rotors for watering specific zones. Also, choose heads with check valves to prevent low-head drainage.
This device connects the sprinkler system to your main water supply while preventing contaminated water from flowing back into the clean water system. Check your local regulations to determine the approved type of backflow preventer required.
These valves turn water flow on and off to different parts of your system. Electric valves connect to an automatic controller while manual valves are operated by hand. Most systems have multiple valves for watering separate zones.
Also called a timer, this allows you to set watering schedules and automatically operate control valves. Get a controller with enough zones for your system and reviews from other homeowners.
Other items include a main shutoff valve, pressure regulator, filter, and various fittings and adapters to connect the parts together. Also, get flexible polyethylene tubing for creating branch lines.
Designing the Sprinkler Layout
Next, measure your yard and landscape to design an efficient sprinkler layout. Consider these key factors:
Divide your yard into separate zones based on plant water needs and sunlight exposure. For example, make one zone for shady areas needing less water and another for full-sun grass requiring more frequent watering.
For proper coverage, space heads about 8-12 feet for spray heads and up to 35 feet for rotor sprinklers. Avoid blocking heads with plants or structures. Draw a rough layout showing sprinkler locations.
Determine the pipe diameter by calculating the flow rate needed for your zones. Generally use 1" PVC for the main line and 3/4" PVC for branches. Upsizing pipe is better than undersizing.
Confirm your available water volume and pressure by checking your main water meter. Low pressure may require a booster pump for adequate sprinkler performance.
Map out trenches running from the water supply to each sprinkler zone. Lay pipes 18-24 inches deep to prevent freezing. Minimize trenching by grouping sprinklers into zones along common pipe paths.
Installing the Piping and Wires
With your system components and layout planned, it's time to start installation. This involves digging trenches, laying pipes and wires, and connecting everything together:
Use a shovel for small projects or consider renting a trencher for larger yards. Dig trenches 18-24 inches deep for optimal pipe protection.
Assemble the main line and branch pipes using proper solvent welding. Install pipes in the trenches with slight slopes to allow drainage. Avoid low spots where water could collect and freeze.
For automatic systems, run low-voltage control wires through 1/2" PVC conduit buried 6 inches deep. Use different wire colors for each zone to simplify connections.
Follow instructions to install components like backflow preventers, valves, and filters using the correct fittings. Also, connect control wires to valves and controller.
Temporarily connect garden hoses to PVC ends. Turn on the water and pressurize the system. Inspect for leaks at connections and fix as needed before burying.
Once testing is complete, fill in the trenches and compact the soil. Avoid damaging pipes and wires by hand-shoveling the initial layers of dirt before using power equipment.
Installing the Sprinkler Heads
After the piping and valves are in place, it's time to mount the sprinkler heads:
Review your sprinkler layout plan and mark head locations with spray paint. Space heads in accordance with the manufacturer's recommendations.
Dig a hole at each head location. The depth depends on the specific head, but make holes around 6 inches deep for standard heads.
Cut the PVC pipe leading to each head location. Attach the flexible polyethylene tubing with appropriate fittings.
Secure each head to the flexible tubing using the manufacturer's instructions. Position them vertically with the sprinkler nozzle at ground level.
Turn on the water again and test operation zone-by-zone. Adjust any heads not aligned properly or overspraying onto walkways and structures.
Fill in around heads with soil and sod or seed over trenches to complete the system. Run through several test cycles to confirm all heads are operating correctly.
Programming the Irrigation Controller
After finishing installation, program your system's automatic controller with the proper watering schedule:
Check typical peak watering restrictions for your area. For example, regulations may prohibit watering between 10 AM and 6 PM or limit watering to 2-3 designated days per week.
Determine appropriate run times for each zone based on factors like soil type and sprinkler flow rate. For instance, sandy soil may need shorter cycles of 10-15 minutes.
Divide the zone's total run time into multiple shorter cycles. This allows the soil to absorb the water rather than overflowing and running off. For example, program three 10-minute cycles per zone instead of one 30-minute run time.
Update the program several times per year based on weather. During hot, dry periods, increase watering frequency and duration. In cool weather, reduce watering to avoid oversaturation and runoff.
Use advanced controller features like rain delay to temporarily halt watering after rainstorms and budgeting to limit total usage and avoid excessively high bills.
Programming the controller properly is key to efficiently watering your yard without wasting water and money. Adjust and refine your schedule as needed by observing sprinkler performance.
Maintaining the System
Like any major system, an underground sprinkler system requires ongoing maintenance to stay in proper working order:
Inspect all system components and test operation before the peak watering season starts. Fix any winter damage like cracked pipes. Also clear debris around heads.
Checks for Leaks
Periodically check pipes, connections, and heads for leaks, especially at the start of the season. Catching leaks early prevents significant water loss and damage.
Regularly remove and clean out the system's filter per the manufacturer's directions to maintain adequate water flow.
Manually operate each zone in fall to drain all water from pipes before winter freezing temperatures arrive. Turn off and drain the backflow preventer and other components as needed.
Electric valves may stick after long periods of disuse. Turn valves on and off manually several times per year to prevent them from seizing up and failing.
Ensure all sprinkler heads remain properly aligned with the surrounding landscape. Settling soil can tilt heads and disrupt the watering pattern over time.
Maintain a written record of the current controller programming and update it when making seasonal adjustments. This allows easy reprogramming if the controller resets or fails.
Doing preventative maintenance extends the life of your sprinkler system, prevents major failures, and ensures optimal performance season after season.
Benefits of Installing Your Own System
While installing an underground sprinkler system requires significant planning and labor, doing it yourself can save thousands of dollars in professional installation costs. Other advantages include:
Customization - You can tailor the system specifically for your yard's size, shape, and water needs.
Upgrade Options - You can opt for higher-end components like precision pressure-regulated heads.
Cost Savings - DIY installation costs a fraction compared to contractors.
Satisfaction - You'll get the pride and satisfaction of completing a major home improvement project.
Control - You'll know the system inside-out for easier maintenance and troubleshooting.
As long as you're willing to undertake the planning, permitting, purchasing, digging, and programming, installing your own sprinkler system can be a very rewarding DIY project that leaves you with a top-notch irrigation system.