Handling Your Haystack

Hay can be a barn’s biggest expense and biggest hazard. Here’s how to protect your investment and your horses.

When you purchase good quality hay, you want to protect your investment. Hay is a perishable commodity, so careful attention paid to stocking and handling is money in the bank.

Planning for Storage

Storing hay is like stocking your pantry. You want sufficient forage to supply your horses’ needs so that you don’t have to shop every few days. But don’t buy excess feed if you don’t have a secure place to put it.

How much hay you choose to store depends on your situation. With limited shelter, you’ll buy smaller amounts more often. But, with a barn full of horses, you can save money by buying several tons in one delivery. Then comes the problem of storing this large delivery in such a way that no bale is wasted and the threat of fire is kept to a minimum.

Barn or Tarp?

It goes without saying that water damage and mold can eat up as much as 10 percent of an uncovered stack. Not to mention that moldy hay can be a health hazard for horses. Covering your hay also protects against dust and dirt and intense sunlight, which can brown exposed hay bales and over the months, can bleach the hay to a cream color. In addition, the exposed hay is drier and probably loses its palatability. And don’t ignore what lies beneath; water can also seep up into the bottom layer like a sponge, so keeping the bottom layer of bales off the ground is important.

For best results, you can store your hay either in a permanent structure, such as a barn or shed, or under a fabric cover, such as a tarp. The traditional hayloft is no longer a recommended means of storage because storing tons of highly flammable hay above horse stalls can lead to a disaster. If you do store hay in the horse barn, install a firewall between the horse stalls and hay storage and ensure hay conditions by regularly checking bales for signs of excess heat. Also, contact your insurance agent about obtaining insurance coverage on baled hay.

Permanent structures are more costly, but also more durable. And you can choose the type of structure that suits your situation: fully enclosed, or open on any or all sides. You can add fabric curtains to an open-sided shed to protect hay from blowing rain, snow and dust. Your barn can be almost any size, from a small, stall-sized hay shed that can store up to 100 36-inch bales, stacked in four layers, to much larger structures for bulk deliveries. You can obtain plans for barns of various sizes from Midwest Plan Service (see sidebar at the end of this article).

Tarps are less costly, and can provide equal protection against the elements—so long as they remain completely intact. A hay tarp, correctly fitted with tiedowns, “will last four to five years if you attach it right,” says Glen Knopp, president of Inland Tarp and Cover in Washington. He noted that tarp problems occur if the tarp is too loose and flexes in the wind, deteriorates due to inadequate UV protection, or isn’t rolled up and stored carefully.

Setting up a tarp properly requires some care. “When you stack hay, put a peak on the stack so water runs off,” advises Knopp. “And leave the ends open, so you allow air to circulate through and reduce wind whip. If you close off the ends, with more wind velocity you have more air pressure difference, so wind lifts up and billows the tarp. Peaking it up helps equalize the air pressure.” The improved air circulation also helps prevent heat buildup.

Lastly, with tarps, sometimes it’s just a small hole or leak that can do the most damage. “With a hole in a hay tarp, water causes hay to rot from the top to the bottom,” Inland’s Knopp says.

Terri Powers, of the Gourmet Hay Company in New Mexico, agrees. “The worst kind of wetness on hay is not surface wetness. It’s a pinpoint hole on a tarp, where rain goes down through every bale.” Even a hole caused by something as small as a mouse can allow enough water to ­funnel down the stack to cause problems.


Besides preserving hay under cover, your storage site must allow for efficient and convenient access and movement of hay.

Consider the size of the delivery truck, and how close it can park beside your storage location. If ­

you’re tarping hay, you can easily set up the stack near a gate or driveway. With a permanent structure, be sure a truck or truck and trailer can maneuver close to the building. If your building is tall enough, the truck can back right in and stackers can easily unload.

Figure out how you’ll deliver rations to the horses. If you carry eight pounds of hay from the hay shed to a stall or paddock, walking 40 feet won’t pose a problem. Multiply that by 10 or 20 horses and you’ll need a utility cart or wagon pulled by a garden tractor. So locating the storage site in a place central to the barns and paddocks on a flat grade would make pulling that cart a little easier.

Finally, pay close attention to drainage in the area. Make sure that water runoff will not end up in your hay shed and that a lake won’t form under the tarp.

Protect bottom bales from moisture by elevating them. You can stack hay on wood pallets or spread a plastic sheet over the ground. “An elevated rock pad is best,” says Knopp, because it provides drainage and ventilation. “Don’t use fine rock, but larger, crushed rock,” he advises.

Stacking Advice

Whether you store your hay in a barn or under a tarp, stack it properly to ensure stability, safety and optimum ventilation. For maximum stability, “don’t ever put a bale on top of a bale going the same direction,” says Powers. “Make four-bale ‘cubes,’ and stack the edges evenly.” She adds that slick grass hay bales need to be stacked tighter, to prevent a stack from sliding.

Due to its moisture content, hay needs ventilation to dissipate and cool any excess moisture and to prevent heat buildup. The advantage of an open-sided barn or tarped stack is that these let the hay “breathe.”

“The traditional hayloft is no longer recommended…”

When you are expecting a hay delivery, prepare your site by clearing out the old, loose hay. If you still have bales left in your barn, move them to the side or to a different location to separate them from the new hay. You might want to complete feeding most of the older hay, then feed a blend of new and old so your horses can adjust to a different cutting.

Fire Prevention Tips

Hay can be fuel for a firestorm. Hay ignites easily and burns rapidly, whether it’s dry or wet.

Wet, hot bales, with a moisture content above 25 percent (good quality hay has a moisture content of 15 to 20 percent), can ignite through spontaneous combustion. Even freshly-baled hay can overheat and burn in as little as six weeks after baling and transport. To make sure this doesn’t happen with your hay, monitor your stack with a temperature probe. An easy way is to insert an iron or copper rod into a bale in the center of the stack. Hay insulates, so the center will be the hottest part.

Remove the rod after an hour, and hold it in your hand. If it’s too hot for you to hold, your hay is too hot. You can also try opening a bale and inserting your hand deep into the hay to feel if it’s too hot.

How else can you tell if a stack is heating up? Danger signs include a mild caramel odor, warmth in an enclosed barn or even steam. A strong scorched smell is a sign of an emergency. Call your fire department if you suspect your hay is too hot; moving hay that’s starting to smolder can cause it to burst into flames.

Reduce fire hazards by checking suspect hay daily to be sure the temperature drops. And make sure your storage is at least 30 feet from the horse barn.

For additional information on spontaneous combustion and how to prevent it, see “Silo and Hay Mow Fires on Your Farm” from the Ontario Ministry of Agriculture, Food and Rural Affairs at the Website listed below.

For many barns, hay is the most important part of the horse’s diet and the most expensive. By rethinking the way you store hay, perhaps you can take advantage of better pricing with bigger deliveries. And, well-planned storage can help protect that hay investment allowing you to feed every pound you buy.

Building a Hay Barn

Your hay barn can be a fully enclosed building or a simple roof supported by four posts. Choose the structure that fits your climate and budget. You can build your own barn from plans, or assemble a kit. Barn manufacturers sell modular buildings such as the three-sided hay shed. The open side simplifies stacking. In a humid climate, with 90 to 100-percent humidity conditions, choose a hay cover with all four sides open. This will allow for enough ventilation to help prevent hay from molding. Be sure your barn is tall enough for working room during stacking. A roof only 10 feet tall limits you to a comfortable four or cramped five bales high. Fifteen or 18 feet increases stacking capacity and reduces bumped heads.

For hay barn plans, contact the Website listed at the end of the article or your county extension office. Here are a few typical barn sizes, with typical costs:

  • Pole barn, 30 x 60 x 18, $10,000
  • Prefabricated metal barn kits: 20 x 10 x 10, $2,830; 30 x 60 x 12, $7,720

For More Information

Inland Tarp and Cover

Inland Tarp manufactures tarps of a North-American-made polyethylene fabric.

Hay barn plans from Midwest Plan Service, Iowa State University (click on “Free Materials”)

“Use of Microwave Drying to Determine Moisture Content in Forage”

Departments of Animal Sciences and Agronomy, Purdue University

“Silo and Hay Mow Fires on Your Farm”

Ontario Ministry of Agriculture, Food and Rural Affairs






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