When making or ordering a custom field cover for a baseball facility, you’ll start the process by selecting a material. Don’t underestimate the importance of this decision. It’s easy to overlook the material selection process since there are few options available for most pre-made designs. When you’re finally presented with a wide range of choices for a custom cover, it’s tempting to just pick the most familiar one and go with it. Yet the PVC, nylon fabrics, and basic polyethylene blends used for most baseball field covers are far from the best possible materials. Learn what’s wrong with many of the flexible geomembrane and fabric materials used for field covers and what to choose instead.
The Best Choice: Reinforced Polyethylene
The best possible material for a baseball field cover is reinforced polyethylene, also known as RPE. RPE features a reinforced core that gives it greater strength and tear resistance than other forms of basic polyethylene. Other materials also come in reinforced variations, but they lack the UV resistance that RPE provides. High UV resistance is essential for any athletic field cover because the materials are used on the surface of the ground and subjected to intensive sun exposure. RPE materials work well for all kinds of field covers, including those used for both long- and short-term installations. The highly impermeable material keeps water out of the soil while creating the blackout conditions needed to control the greenhouse effect. We use RPE here at BTL Liners for our premium field cover products to ensure they last as long as possible while being lighter and thinner than similar materials.
Good Choices: Reinforced Polypropylene, High Density Polyethylene, and Low-Density Polyethylene
If RPE isn’t an option for your baseball field, the next best option is some other form of polyethylene. Low density polyethylene (LDPE) is flexible and offers mixed UV resistance, but it’s not as durable as most other forms of polyethylene. On the other end of the spectrum, high density polyethylene (HDPE) is tough but stiff and hard to fold and move as needed. That’s why RPE products combine both types of polyethylene into one to take advantage of the benefits of both materials. Another option is reinforced polypropylene, or RPP. It’s not quite as UV resistant or tough as RPE, but it’s still a better choice than other polyethylene products in many cases.
Acceptable Choices: Polyvinyl Chloride
Polyvinyl chloride, or PVC, is the material most commonly used for baseball field covers. Yet as you can see, it’s not even a good choice or the best one. It’s only acceptable in most situations, especially where long-term covers are needed over the winter or between seasons. PVC is thin and flexible, but it’s particularly prone to both tearing and UV damage. Many managers are dismayed to find the PVC breaking down rapidly after being exposed just a few hours per day. UV resistant blends are available, but they come at a higher cost than many RPE and RPP products. Reinforced PVC is still weaker than other polyethylene products, so stick to RPE whenever it’s available.
Poor Choices: Nylon Fabric, Rubber Sheeting
Avoid any of the thin nylon ripstop fabric tarps you’ll find commonly sold as baseball area covers. These materials simply can’t handle being dragged over the ground or stretched by the wind and can tear within weeks of use. You’ll also find that any water that accumulates on the surface of one of these covers easily soaks through thanks to the wicking effect of the fabric. Stick to impermeable membranes instead like RPE. Rubber sheeting, such as EPDM pond liners, are not a good choice for athletic fields. They’re too heavy and stiff to handle regularly without tearing up turf and soil alike. Folding and unfolding them quickly forms creases and tears. You’ll also find the weight is far too heavy for the turf, leading to crimping and blade loss if the cover stays on for any amount of time. Avoid all rubber sheet materials when making new baseball field covers from scratch.
UV Resistance for Exposed Use
No matter the material or manufacturer you choose for a field cover, make sure it’s rated specifically for exposed use for high UV resistance. Many people inadvertently order materials intended for lining a pond or using under other materials rather than on top of them. These liners use the same basic materials as covers, they’re just not designed with daily UV exposure in mind. Stick with a cover product rated for years of constant UV resistance to avoid early failure.
With these guidelines, you should find it a little easier to narrow down your material choices for a new baseball field cover. All of these recommendations apply to every size and type of field cover. Even if you need an open mesh to encourage germination or leave a cover in place during play, you’ll find options made from RPE or RPP on the market. For solid covers designed to protect from rain, shop our selection of cover materials here at BTL Liners.
