The first step in choosing one of these is to decide how you'll use it. Common uses include storing bulky items like No. 10 cans, bags of flour and rice, and cases of frozen food. Figure out how much weight your rack will need to support. Capacities range from less than 1,000 pounds to more than 4,000 pounds, so it's important to know the weight of what you intend to store and to never exceed the weight limit of a rack, doing so could cause it to collapse.
Both stationary and mobile units are available. Mobile units make it easy to transport and rearrange stored items, but typically have lower weight capacities than stationary units. That's because their casters aren't built to carry such heavy loads, so putting too much weight on them can lead to wheel failure and may cause the bulky products to fall on the operator.
Slat-style racks provide support with broad, flat crossbars with gaps between that enable air to circulate. This is ideal for storing fresh foods like potatoes and onions.
Slotted tops have louvres that allow air circulation like slatted shelves, but with more support for smaller or irregularly shaped items that would fall through broad gaps.
Racks with squares on the surface form a structural grid. These offer air circulation with increased structural integrity. The tradeoff is that the spaces in the grid harbor dirt and debris, so they must be kept clean.
Solid shelving offers maximum support and can help contain spills. These are not ideal for fresh food because they don't allow air circulation.
For the best of both worlds, consider a frame with a mat that slips over the rack. These provide the structural advantage of wire shelving but with a solid surface. The mats can be slipped off and run through the dish machine when they need to be cleaned.
Aluminum is affordable and lightweight. Unlike steel, it will not rust. It is not quite as strong as steel, so it will not hold the same capacity and is more easily bent or dented.
Wire is the more rugged form for metal dunnage racks. It is made with stainless steel or epoxy-coated steel and will resist rust unless it is chipped or scratched. If you'll be putting heavy metal items like food cans or kegs on your rack, opt for stainless steel, as sliding those items on and off the unit will quickly chip off epoxy coating.
Polymer is a durable and rust-proof plastic. Many manufacturers include an antimicrobial compound in their polymer to slow the growth of bacteria and other microorganisms. Polymer is also lightweight and easy to clean.
Metal racks are often finished with an exterior coating, each has its own advantages:
- Epoxy is used to coat steel wire shelving. It is the most affordable coating and will not rust as long as it remains intact. However, if it is worn off or chipped, this will allow rust to form on the metal beneath.
- Like epoxy, a chrome coating is used on steel wire shelving and will remain rust free. Although it is more durable than epoxy, it can chip away after years of use, allowing rust to form on the exposed steel wire.
- Stainless steel is the most rugged metal option. It resists corrosion and has the highest weight capacity. It's hard to chip or scratch, but if it is damaged, rust can begin to form.
- Polymer is a plastic alternative to steel; it will never rust or corrode and can hold as much weight as the metal options. It also has the advantage of being easy to clean.
When a dunnage rack is manufactured, it is either welded, formed, or assembled together. This means that it will be ready to use when it arrives at your facility. Formed racks are the strongest; their main components are each formed of one continuous piece of metal. Because there are no joints, this kind will maintain its structural integrity over time. Welded units are the second most sturdy. Their components are welded together, which makes a strong structure, but the joints can become worn and weaken over time particularly in demanding conditions, such as in a hot and steamy kitchen, or in a cold and humid freezer. Assembled units are put together with hardware, which must occasionally be adjusted and replaced to maintain the integrity of the unit.
- Some styles are interlockable, meaning multiple units can be joined together to form one continuous rack. These are useful if they need to span underneath one long shelving unit.
- Others have handles to make them easier to pick up and relocate.
- Wire and aluminum units that need extra support will be reinforced with a channel frame underneath the rack surface to provide structural integrity.