As temperatures begin to drop across the country, contractors are gearing up for another season of irrigation shutdowns. Systems need to be winterized before overnight temps hit freezing and damage may occur.

From large commercial properties to residential customers, now is the time for contractors to start planning for and implementing their irrigation shutdown services. Here’s a timeline, the tools needed, step-by-step best practices and why it’s important to properly shut down irrigation systems.

When to shut down

While the exact date depends on the weather conditions, Sean Lynam, general manager at LMI Landscapes, says his crews typically start shutting down systems on Oct. 1 and continue through the month until everything is properly winterized.

Part of the company’s process includes scheduling shutdowns with customers, as well as internally with irrigation technicians. Customers will need to be at home (or provide access) if their cutoff valve and timer are located in their garage or basement.

LMI Landscapes has more than $25 million in annual revenue and locations in Dallas, Austin and Denver. It provides commercial services, including landscape maintenance, design/build, irrigation and snow removal.

“Plan for system winterizations well in advance,” Lynam says. “Every landscape company in town will be winterizing systems at the same time, and if you haven’t planned accordingly, you will be hard pressed to get an air compressor — putting your customers’ systems at risk for potential damage.”

Michael Kukol, president of Horizon Landscape Co. in Wyckoff, N.J., says his team starts with a few irrigation system shutdowns in September, but they really kick it into gear the first week in October.

“We try to be done with them all by Thanksgiving,” Kukol says. “After that, we pick up the stragglers, but it can often be too cold to do a good job with frozen backflows and exposed pipes, especially as December hits.”

The company’s customers are 90 percent residential and 10 percent commercial properties. Horizon provides landscape maintenance, design/build, irrigation, lawn care, pest management, lighting and snow and ice management services. Its annual revenue is $4.5 million.

Equipment for the job

Another part of the planning process should include equipping teams with the right tools for winterizing systems.

“The irrigation techs all need to have a commercial compressor, air hose and fittings to properly affix to backflows, in addition to their standard irrigation parts in order to make any necessary repairs during the system blowout,” Lynam says.

For shutdown services, Kukol’s team uses a large commercial tow-behind compressor that puts out 180 cubic feet per minute (cfm), and it sometimes uses two of them together for large commercial properties. For most residential properties, 120 cfm works well, he says.

“We have them set to 80 psi to avoid damaging anything,” Kukol adds about the residential systems.

Kukol’s company owns its own compressors and has electric reels on them with 250 feet of 0.75-inch hose. It also has 25-foot hoses to be used on larger commercial projects because there is a lot of restriction of air going through the hose, he says.

“If you look it up online, you will be amazed at the friction loss for air flowing through a hose,” Kukol says.

In addition to tools and equipment for shutting down the systems, foam-insulation tape is also needed on the job to protect the main shut-off valve (if outdoors) and other above-ground piping from freezing.

Proper techniques

Contractors should create an irrigation shutdown checklist for their crews to follow on each property to ensure no steps are missed and each service call is uniform. Make the document part of the irrigation team’s training beforehand, as well as something to carry with them to the job site.

Technicians should start by locating the shut-off valve and turning off the water supply on the property. Its location should be included in the property’s data sheet, along with any other specific information or instructions for winterizing the system, like faucet zones and pumps. If there are pumps, turn them off before the shutdown process begins to prevent damage.

After the water is turned off, Kukol’s crews start by connecting to a blowout port, opening a zone and then opening the valve to the air compressor. “If it is a big system, we may blow out the farthest zone first to move most of the water out of the main lines,” Kukol says.

From there, they go through the system one zone at a time. Sometimes, they will go through the system twice if it is complex. They continue to blow air through the lines until only fog comes out of the heads.

“We do not allow the air to flow so long that the nozzles start to spin around too quickly,” Kukol says. If the nozzles whip around too much, they may damage the gears.

Next, they partially close the ball valves on the backflow, and they finish the last zone. After they turn off the compressor, they let the air exit the irrigation system and turn off the controller. If the blowout port is outside, they’ll leave it open — and if it’s inside, they close it.

They also turn off the controller but leave it plugged in so the memory and schedules aren’t lost.

Potential problems

Failing to winterize irrigation systems or not shutting them down properly can cause several costly issues. Backflow devices and plumbing can crack from being exposed to the elements, Kukol says. Heads — especially ones on risers or high-pop sprinklers — can also crack, he adds.

Being in New Jersey, Kukol and his team primarily use black polypipe for irrigation. If systems have not been winterized in seven to 10 years, that polypipe will randomly start to have splits during the year, he explains.

“They can tolerate the stress of freezing underground for several years, but it eventually catches up, and you have repair after repair of the pipe in the ground,” says Kukol.

From pipes to valves and heads, all of the damage from these components freezing can add up.

“This can lead to costly repairs the following spring — and potentially water damage if the system is activated with freeze damage,” Lynam says.

A proper shutdown will reduce the chance of issues during the winter and also ensure the irrigation system is ready to start back up come spring. It can also be a time for technicians to identify and repair anything else that would cause problems during the next year.