Underground sprinkler systems are available in several models ranging from simple to sophisticated. These may include a moisture sensor or an electronic timer. In addition, depending on what you want to water, you can choose from a sprinkler of adjustable or fixed height. The first is suitable for watering a lawn, while the second is ideal for vegetable gardens and tall grasses.

Before installing an underground sprinkler system, measure the flow and pressure of your water supply. It is crucial to have these data on-hand because they depend on the number of circuits to be assembled. In general, the flow is mentioned in your subscriber agreement. To check it, take a 2.5 gallon bucket (10 litres) and measure the time required to fill it completely. The flow’s value is obtained by dividing the bucket’s volume by the filling time and multiplying the result by 3.6. As for the pressure, it is also mentioned in your subscriber agreement. To check it, it is advisable to call a plumber to install a pressure gauge on the water supply line. Measuring the pressure will be carried out with all other taps closed. For optimum performance, the pressure should be between 2 and 5 bars. Once you have this data, make a layout of your garden by including your underground system and the water supply line. The network should have at least cover 30% of the surface area for a homogeneous water distribution.

Tools and irrigation equipment

You must have a spade at your disposal for digging trenches. To press down the soil, get yourself a tamper. You also need a screwdriver, clippers and a wheelbarrow. Also, plan for protective clothing and gloves. In regard to the irrigation equipment, most components are supplied with the watering system. Among these elements, you have the pipes for the pipelines. 3/4 inch (19 mm) reinforced water pipes are recommended. The water saddle tees are used as differentiators and mounting brackets for the sprinklers. For the system, you must have different types of T, L and right angle fittings. There are two types of sprinklers: the nozzles, which are fit for small surface areas and the turbines which are suitable for larger ones. It is unnecessary to mix nozzles and turbines on the same system. The sprinkler system also includes a control switch that facilitates the creation of multiple networks and serves as a programmer to control solenoid valves. The latter are used to open and close the water passage. The collector is installed between the solenoid housing and the water supply line. Finally, the underground installer can make the connection between the water supply tap and the pipe supplying the solenoid valves.

Setting up the watering system

Begin by tracing the system’s outline by materializing the plan on the ground by means of plaster dust. Mark the sprinkler’s location. The plaster powder is also used for marking the trenches’ location. Once this is complete, proceed to divide the lawn into 8-inch wide (20 cm) and 20-inch long (50 cm) sections. Use a shovel to remove the squares of turf sod by cutting the roots horizontally. Put the squares of turf sod aside without piling them up, and dig the trench about a foot deep (30 cm). Take care to stay away from hedges and trees to avoid damaging the roots. Get some plastic sheets on which the excavated soil will be placed. Once the trench is complete, proceed to unwinding the pipes after spreading sand and gravel at the trench’s bottom. Using the clippers, cut the pipe at a right angle allowing for a certain margin of error of about 5 to 10 cm (2 to 4 inches). Clean the inside of the pipes. Secure the fittings as you unwind the pipe. For right angles, use L and T fittings to divide up your system network. To connect two pipes, it is advisable to use a connecting sleeve. At the network’s end, install an end of the line plug. Connect the supply tap at the start of the underground network and deploy a flow pipe to the solenoid valve housing. Assemble the collector using joints to connect the water supply to the solenoid valves. Connect the water supply to the collector and the start of the underground network to the solenoid valve housing. If you do not have a tap outside, you can connect to the home network.

The installation of sprinklers

For each sprinkler, attach the water saddle tees using the supplied screw nuts. Using a drill, make a 1/3-inch to 1/2-inch (8 to 12 mm) hole in diameter on top of the pipe located inside the water saddle tee. Screw the adapted extension to the sprinkler and then screw the sprinkler. Make sure the sprinkler’s top surface of the sprinkler is at ground level. Remember to coat the threads with Teflon. At the system’s lowest point, screw a bleed screw on a water saddle tee. Install the timer away from the rain and connect the solenoid’s control wires to the timer. Remove the sprinklers’ nozzles and manually open the valves to allow the water to evacuate any waste present in the pipes. Put the sprinklers’ nozzles back on and proceed to the sprinkler system to ensure that it is in working order. Check for leaks and adjust the sprinklers’ direction as needed. You can use warning grids to protect your installation. Fill up the trenches by carefully arranging the clods of grass. Water thoroughly so that the soil settles well and use the tamper.

Related posts:

  1. Setting up an underground irrigation system
  2. Installing a rainwater harvesting system
  3. The different types of automated sprinkler systems
  4. Setting up a garden pond

Published in Watering by Alexander on 06 Jul 2011