Upgrades to a Caterpillar Tunnel or Hoop House

What Are Caterpillar Tunnels?

Caterpillar Tunnels are relatively inexpensive, temporary hoop houses that resemble the bug they are named for. 'Cat Tunnels' are designed to be structurally simple and low cost. For this reason, they lack many of the components that add to the rigidity of a structure, including endwalls.

The design relies on a rope system to secure the plastic. This feature does not usually fare well in windy or snowy climates. This could mean losses for your farm if the structure were to be caught in bad weather.

For this reason, we only sell high tunnel hoop houses. If you already have incorporated a caterpillar style tunnel into your operation, it is absolutely possible to reinforce it, and in our opinion, you should.

Upgrading A Caterpillar Tunnel

Many of the same upgrades available for hoop houses can be modified to work for a caterpillar tunnel. Endwalls, Hip & baseboards, and rollup sides can be added along with purlins to replace the strap style bracing. With these adjustments, a caterpillar tunnel can be modified to increase durability and allow for a more permanent structure.

Why We Prefer Hoop Houses Over Caterpillar Tunnels

Many farmers start with a caterpillar tunnel as it is a low cost startup, but find a need for more durability. The design of the caterpillar tunnel was made with lowest cost in mind enabling it to be a quick return on investment option.

We choose not to carry caterpillar style tunnels as we believe hoop houses are a better initial investment.

Check out this article that goes into further depth about the differences between the two greenhouse structures.
Upgrading a Hoop House Greenhouse

Upgrading A Hoop House

Options like roll up sides, insect netting, shade cloth, inflated double layers of plastic, ventilation all help improve the growing environment for the plants and the comfort of the people working in the hoop house

Deciding to invest in these options should be based on production planning, not an "I don’t know what to do, so I’ll buy it all” shotgun effect.

Upgrades need to come with the understanding that a hoop house is not typically an environmentally controlled structure, no heaters or powered cooling units. It is not meant to be a four-season greenhouse.

Cost v. Benefit of Hoop House Upgrades

A great example of this is with the decision to add or not add a double layer inflation kit. Often, when new hoop house buyers inquire about whether or not to add a double layer, the answer is variable.

When deciding if this upgrade is right for your farm, consider the R value ( a material’s resistance to thermal conduction) of a double layer system. A double layer of greenhouse plastic hovers around 1.6 so the holding power of heat isn’t the silver bullet some farmers are hoping for.

Next, it's important to determine if the cost of a second sheet of greenhouse plastic, a blower, the electricity needed to run the blower, the initial labor to install the double layer and blower, plus the eventual reskinning of the greenhouse film is going to yield the returns needed to justify the cost.

Ask yourself if you are going to add passive heat like solar barrels, adding active heaters that you are feeding gas or wood, growing cold sensitive plants like vine crops, and growing zone considerations like length of available daylight.

If you live in a temperate grow zone and plan to grow cold loving brassicas, you may not even need a second layer. Whereas, the double poly upgrade would be great for those dealing with coastal winds or those wanting to get a head start on starts for spring.

If you plan on growing tomatoes in an unheated hoop house in Minnesota year- round, you will be very disappointed when the temp gets consistently below 65° no matter if you have a second layer or not. It is all part of the checks and balances you need to think about when planning your farm.

Other Hoop House and Caterpillar Tunnel Upgrades

Does your area have grasshoppers? You might benefit from insect netting. Insect netting has come a long way. New technology in insect netting has made it possible to deter insects without the use of harsh chemicals. Insect netting is easy to use, breathable, and can even be used to contain pollinators or beneficial insects that you wish to keep near your plants.

Are you in the southernmost states and get too much heat in the summer season? Rollup sides and gable vents will keep your warm workers and your plants a little cooler. Rollup sides are easy to install and use.

Having an understanding of what a hoop house is designed to do, seasonal extension, will make it easier to pick the best options for your farm. Remember, upgrades can be added later on as you are able to pin down your specific growing needs.

Why We Prefer Hoop Houses

Want to learn more about hoop houses?