f you’re installing an irrigation

system, and you’re not planning on

using an irrigation valve box, you

might want to reconsider before it’s

too late. With all the work and

expense put into designing and

installing the system, the few extra

dollars an irrigation valve box runs

will pay for itself in ways that can’t

be measured in dollars and cents.

Valve boxes are used to conceal and protect the valves, fittings, wiring and manifolds that comprise an irrigation system, by housing those components within an underground box. They are also a very efficient way to maintain those components.

In the old days, irrigation valve boxes were usually made of cast iron or concrete. They were heavy, in the case of concrete, brittle, and took a lot of equipment and manpower to install. In addition, because of the weight, shipping them to the jobsite was cumbersome.

Now, the material of choice is plastic; and the plastic of today is not your father’s plastic. Strong and resilient, plastic boxes are easy to handle, easy to work with and very economical.

Still, you might be wondering, why bother? “I’ve never used them before, why start now?” you may ask. “Won’t it take more time to install one?”

The answer is no; leaving an irrigation valve box out of the equation is not going to save you any time. You have to install the irrigation system one way or another. When it comes to housing the valves and manifolds, you have three options: you can put them uncovered in a hole in the ground; you can put everything above ground; or you can protect the system’s most important components in irrigation valve boxes.

If you’re considering the first option, be forewarned--exposing valve controls and manifolds to the elements is not the best thing for those components. They’re not designed to be subjected to the extremes of weather. Ice and water could damage the valves and break the plastic housing on them if it gets too cold. And throwing a piece of plywood over the hole is like putting a finger in a leaking dike. It’s ineffective and downright dangerous.

Too often, some landscape contractors decide to go the second route and leave valve controls and manifolds above ground. It may seem the easiest way to go, but it’s a decision so fraught with peril, it’s difficult to find where to begin to say what’s wrong!

So let’s start with the obvious. It’s just plain ugly. You’re a professional. You’ve been hired to do a professional job. You’ve done all your homework and are set to install an irrigation system that will effectively water the landscape and efficiently conserve water. Why would you want these valves and pipes dotting the landscape, making all your efforts look more like the handiwork of Johnny Do-It-Yourself?

If the aesthetic value of using irrigation valve boxes isn’t convincing, then look at the practical reasons. First of all, it protects the valves, solenoids, manifolds, wiring and whatever else you need to install. When they’re above ground, they can be vandalized or easily damaged. And in a landscape environment, the wheels or blades of a mower can hit them. Not to mention the grass and weeds that will begin growing around the devices. If you use a string trimmer, there is even more of a possibility that you can cut the wires or knock off a solenoid.

Then there’s the fact that it will make life easier for the property owner or whoever ends up taking over when you’ve completed the project. “If you’re creating a landscape situation, you’re trying to make it as simple and user friendly as possible for the people that are going to have to deal with it on a daily basis,” says Jim McKinnon, of DFW Plastics, Ft. Worth, Texas. “You might be the installer and walk away; however, it would be fair to say that the people left with the newly installed irrigation system should be able to have easy access.”

“The advantage to using an irrigation valve box is that it gives you easy access to the functioning parts of an irrigation system,” says Robert Hickey of Pentair Plymouth Products, Sheboygan, Wisconsin. “You really only have two moving parts in the system: sprinkler heads and valves. If you have a problem with the sprinkler heads, they are right there at ground level. Why wouldn’t you want easy access to the system’s only other mechanical part?”

The irrigation valve box also tells you where everything is. It puts the most vulnerable parts of an irrigation system in a neatly, organized place and gives you access to all those components. The beauty of irrigation valves boxes are that they will enhance the irrigation system you’re set to install without a major change in plans or design. All the elements of the system will remain the same.

Are you now ready to get started? Where do you begin? It’s easy! The type of job you’re doing will dictate what box is best for you. Generally, valve boxes are either round or rectangular. Round boxes usually handle one irrigation zone. Rectangular boxes house several. The system you’re installing may need both, depending on the size of the zones that need coverage.

Let’s start with creation of the irrigation zones for the job. If more than one zone is called for, you’ll need a manifold, and valve controls for each zone. Usually, those valves are electronically operated by a remote control device. So, in addition to water lines, you’ll have wiring attached to the valve. Instead of leaving all that unprotected, you’re now going to dig a hole and protect them with an irrigation valve box.

“You don’t have to dig a deep trench,” says Hardy Rost, of Dura Plastic Products, Beaumont, California. “You bring your main in and run it to the valve, then out of the valve. You figure out the different zones you’re going to have, and you go from there. Then you put the box around them, fill dirt around it, put the lid on it, bring it up to grade, and you’re good to go.”

The irrigation valve box is accessible from the top of the ground. The typical irrigation box is no more than 10 or 12 inches deep; six inch extensions can be added to the top of the valve box when an irrigation system is buried more than a foot underground. That usually happens in cold weather applications, when the frost line is deeper than a foot.

Irrigation valve boxes don’t have a bottom on them, so in a sense, they’re not true “boxes.” But there’s a reason for that--they don’t need a bottom. The elements that will damage the valves and manifolds are coming from above, not below. And the open bottom allows you to easily install the irrigation valve box over whatever lines and valves are going to be housed inside of it.

Since most irrigation valve boxes meet American Standard of Testing Methods (ASTM) specifications, McKinnon says there’s little reason to look at technical specifications when choosing which brand to use. “You need to be looking at how that product is designed, and how it’s going to go in the ground and how accessible it is. What the contractor ends up doing basing it on price… what best fits his budget.”

According to McKinnon, price doesn’t always reflect the quality of one brand over another. He says that the manufacturing process of the plastic affects the price of the product. Consequently, just because it’s more money doesn’t make it better.

Where you install the irrigation valve box will determine what box is best suited for the job. If you’re on a mountain or on a hill, you’ll want a box with walls that can withstand the forces of dirt and gravity. The soil you’re working with also enters into play. You can use a box with thinner walls in clay or sand. Rocky dirt is less forgiving.

You also need to take into consideration the traffic that’s going to come across the valve box. Valve boxes are rated for light duty and pedestrian traffic. Obviously you’re not going to put one in the middle of a highway! Ideally, you want to put them out of the way, off the beaten path. But that’s not always possible.

The smaller 6” and 10” round boxes shouldn’t be in the middle of a walk path. They’re not designed for that. They should be off to the side where there’s light traffic, or no traffic, over the box. Larger, rectangular boxes should be able to handle foot traffic and light vehicular traffic. It’s probably best to err on the side of caution.

“I wouldn’t recommend anyone to go with a lesser box,” says Rost. “My philosophy is to do the job, do it once, and do it right. The price difference between a thinner walled box and a thicker walled box is only pennies. I would rather put the heavy duty box in and know I’m never going to have problems with it; that no one’s going to get hurt because of it .That I did the job and did the best I could.”

The sizes of the rectangular boxes range from 10”x15” to 15”x21” with slight variations, depending on the manufacturer. Some brands feature overlapping lids; others have a drop in lid that sits inside of the box. Ideally, you should be able to just reach down and easily open the lid on the irrigation valve box.

If the box is out in the middle of a field, you want to make sure its lid is designed to handle the weight of a large lawn mower or the single axle of a vehicle. Your distributor should be able to tell you which irrigation valve box is best suited for the application you have in mind.

Valve boxes also come in a variety of colors: sand for the desert, green for grass, brown for woodchip areas. But perhaps the most important color of all is the color purple. It’s meant for systems using reclaimed water.

Rost stresses that it’s important for people in the irrigation business to install both a purple box and lid in those applications, and not just a purple lid with a black or green body, “just in case someone steals your lid, or it gets blown away in the wind. The lid may not be there forever. If someone looks down at a box and sees that it’s black or green, they won’t know to put a purple lid back on it,” says Rost. “But if you see a purple box buried in there, you’ll know.”