contents 1. Types of Cattle Guards 2. Cattle Guard Uses 3. Guidelines and Certifications 4. Installation 5. Vehicle Load Table

A good quality cattle guard will be constructed with heavy wall steel pipe and extra thick steel channel. All ends will be capped to prevent rust. In addition, any commercially available cattle guard should be able to withstand the weight of full tractor-trailer loads and any other vehicle that can pass on public highways.

A well constructed, heavy duty cattle guard will provide decades of service with minimal maintenance.

A removable box is handy for cleaning. A flat cattle guard sits inside a sturdy frame box. When the hole under the cattle guard fills up with dirt or leaves, it will be easy to clean out. The flat cattle guard is easily lifted out of the box with pallet forks to clean underneath. With the removable box, you may need to put some support under the cross beams if you have loose ground.

Cattle guard wings are used to keep cattle from jumping the corner of the guard. Wings are used with barbed wire fence. A full height fence along the width of the guard will do as well, but this is not just 3 strand barbed wire, it needs to be a substantial fence. Cattle are not extremely smart, but they can cut the distance in half and hop 3 feet - fencing along the width prevents this. A full fence along the width is generally less expensive than wing options but with barbed wire, the wings are best.

Cattle guard with wings and barbed wire fence

Cattle guard with fence along the full width eliminates the need for wings

You may want to consider bolt-on wings. Although the initial cost is higher, the shipping cost is significantly lower, especially if you need more than one. A flat cattle guard with bolt-on wings can be shipped in a box van which is less expensive than shipping on a flat-bed trailer. Welded-on fixed wings must be shipped on a flat-bed.

The longest single piece cattle guard manufactured is 20 feet. It is difficult to build one any larger due to transport and installation issues, and the problem compounds itself when removal and cleaning is necessary. For spans greater than 20 feet, two cattle guards are installed end-to-end and bolted together.

Boxed cattle guards are essentially flat cattle guards with a steel skirt welded around them to keep dirt from building up underneath. They are designed to lay right on the ground without any footings or a vault and so may move over time. Installation typically includes creating a dirt ramp on either side of the guard. Boxed cattle guards are usually used for temporary or low traffic areas. They are very popular for construction site washouts and can stand the weight of a fully loaded tractor-trailer.

Cattle guard with wings and barbed wire fence

Cattle guards do not stop deer. A deer will jump a 6 foot cattle guard. The most practical way to make a cattle guard wide enough to deter deer is to put two cattle guards in series, creating a 12 foot width. The full 12 foot width of the cattle guard must be fenced for this to be effective or the deer will cross at the ends. Cattle guards are easily bolted together and ranchers have reported the 12 foot width to be effective. Particularly agile deer may still be able to jump across 12 feet. None, however, will be able to cross a 16 foot span.

Cattle guards installed in tandem for a 12` span should also keep most horses in unless you have a horse that is particularly crafty at getting out. However, cattle guards are not meant for horses and a horse could break a leg if they try to cross. A gate is recommended for horses. Mules are a little more sure footed than horses and may not be deterred.

You cannot stop a dog with any cattle guard. The only thing that will stop a dog is a gate. Dogs will walk right across a cattle guard. They will not work for sheep and goats either. Feral hogs are also not deterred by cattle guards. Hogs are very smart and they will find a way in.

Cattle guards are commonly used as wheel washes in construction and oilfield settings to clean heavy equipment prior to transportation. Equipment is easily driven up onto the cattle guard and washed down.

AASHTO Design Specifications
• H-15 (12 tons per axle)
• H-20 (16 tons per axle)
• U-54 (25 tons per axle)
• U-80 (30 tons per axle)

HS20 cattle guards will be certified by an independent engineering firm to meet commercial standards and are intended for government bids. For use on private land, buying standard cattle guards will save you thousands of dollars, are identical in size and are made out of the same materials. They just do not come with the certifications and paperwork all the way back to the steel mill that government agencies require. If a non-rated guard for a private drive is needed, use a standard cattle guard.

General installation instructions suggest digging a 1 foot deep trench that is 1 foot wider than your cattle grid. Pour a 6 inch wide wall around all four sides - the only purpose of this wall is to prevent collapse of the earth into the guard under vehicle traffic. In the bottom of the trench, pour a concrete footer, 12 inches wide and 18 inches deep under each beam of the cattle guard. Install large PVC pipe through the forms to provide drainage. Most designs do not utilize pipes; instead they dig out and fill with crushed rock to form a French drain. If the drainage is particularly bad, run both a pipe and a French drain out into the surrounding ground. Proper drainage will prevent water and rust problems.

Boxed guards are typically put straight on top of the ground. It is perfectly acceptable to use a boxed guard with well compacted soils, especially if the soil has a good rock component like road base. Over time, a pothole may develop at the leading edge - typically going in due to higher entrance speeds than leaving the property. This is easily filled in with a shovel. The box is strictly to keep earth from migrating into the guard. The boxed and removable box options are for temporary uses such as mining, harvesting, roundup and oil well drilling. Any installation intended for over 2 months of use is done with a concrete vault and footers.

Because of the variation in soil conditions and drainage, the concrete foundation (footers) and the vault (wall around guard) are poured on site in virtually all circumstances. To attempt to transport or ship such a system would be extraordinarily expensive, whereas most concrete companies cost around $130/yd plus mileage. The 3-5 yards of concrete you need are far better installed in situ than transported as a solid object. Please be aware that enough variation (manufacturing tolerances) exists in each guard that foundation build should not begin until the cattle guard for a specific location has been delivered and measured.

It is critical that the cattle guard rest on footers that are sufficient to support the full load of traffic. The vault does not support the cattle guard in any manner; it keeps the earth from caving into the guard, rendering it useless and the road impassable. The entire finished depth of a properly installed cattle guard is One Foot. Any deeper and animals can be injured or killed if they attempt to cross the guard. Animals can get out of a 1 foot guard and are highly unlikely to try again.

Every cattle guard installation is unique due to soil conditions, climate, drainage, and intended usage. That being said, if a level footer spans the road and supports each end of the beams, you will get decades of useful service. Footers are not optional. As an example, it would be a disastrous situation if your house is on fire and the pumper gets stuck in your cattle guard blocking the rest of the emergency equipment. Emergency equipment and heavy commercial deliveries are the primary reason these must be poured.

A cattle guard can be placed over a ditch with running water by using a standard flat cattle guard with a concrete foundation. A culvert is placed with the top of the culvert exactly 1 foot below road level. Then footers are poured under each beam of the cattle guard with the culvert embedded in the footers. Next, a concrete box with 6 inch walls is poured all the way around the cattle guard. The top rails of the guard are not supported in any way by the surrounding box - the weight of the vehicle is transferred to the rails, the rails transfer to the beams, beams to footers, footers to earth.

FINAL NOTE: Please be aware that you need to have the proper heavy equipment available at the site of delivery to unload the cattle guards from the back of the truck. Truckers cannot carry the size of equipment needed to move a cattle guard.