What is the best spacing between the bars of a cattle guard? There isn't one spacing measurement that should be applied to every cattle guard. Bar spacing is part of the overall design of the guard and needs to work with the rail shape, supporting structure, intended livestock, and expected vehicle traffic.

For a manufactured cattle guard or installation kit, the spacing specified for that particular design should be maintained rather than changed in the field. Barn World offers cattle guards in several designs and sizes for farm, ranch, private-property, and heavy-traffic applications.

Why Isn't There One Standard Cattle Guard Bar Spacing?

A cattle guard is a complete structure. The distance between its rails is only one part of that structure, so looking at spacing by itself can be misleading.

The design also includes the shape and size of the rails, the distance a vehicle travels across them, the supporting structure beneath them, the overall dimensions of the guard, and its load capacity. Changing one part of an existing design can affect how the entire cattle guard functions.

This is why a generic bar-spacing measurement should not be used as a substitute for the specifications of a particular cattle guard.

Round Rails and Flat Rails Are Different Designs

One reason cattle guard spacing cannot be reduced to a single measurement is that cattle guards are available with different rail designs.

Round rail cattle guards use rounded top rails across the crossing. They are commonly used for ranch, farm, and private-property entrances where livestock control and routine vehicle access are needed.

Flat rail cattle guards use a different top-rail configuration and are available for applications requiring specific load capacities.

Because the rail profiles and overall structures differ, the open space between the rails should be considered as part of each cattle guard's complete design rather than compared as an isolated number.

Bar Spacing Is Only One Cattle Guard Dimension

It's also important not to confuse rail spacing with the overall dimensions of a cattle guard.

When planning a crossing, there are several separate measurements to consider:

• The distance the cattle guard spans across the roadway
• The distance vehicles travel across the rails
• The spacing between individual rails
• The dimensions of the supporting foundation or installation system

Each measurement serves a different purpose. A wider roadway, for example, may require a longer cattle guard across the entrance, but that doesn't mean the spacing between the individual rails should be increased.

For a more complete explanation of overall sizing, see standard cattle guard dimensions.

Don't Change the Rail Spacing to Make a Cattle Guard Fit

If a cattle guard doesn't fit an entrance correctly, changing the spacing between its rails is not the right way to adjust its overall size.

Instead, select a cattle guard with dimensions appropriate for the roadway. Barn World's round-top cattle guards, for example, are available in roadway-spanning lengths of 8, 10, 12, 14, 16, 18, and 20 feet. Choosing the appropriate overall size allows the rail configuration to remain as designed.

This is particularly important with a manufactured cattle guard because the rails, frame, supports, and other structural components are designed to work together.

What About Cattle Guard Installation Kits?

Installation kits and field-installed cattle guard systems can involve more on-site work than a complete prefabricated crossing. That makes it especially important to follow the dimensions and layout specified for the particular system being installed.

A kit should not be treated as a collection of interchangeable measurements. Rail placement, supporting components, foundations, and the finished dimensions of the crossing need to work together.

Before construction begins, review the specifications for the system and lay out the entire crossing. This helps prevent a situation in which rail placement has to be changed later because the foundation or roadway dimensions were incorrect.

Consider the Livestock Using the Property

Cattle guards are primarily associated with cattle, but not every animal interacts with a crossing in the same way. The type of livestock on the property should therefore be considered when deciding whether a cattle guard is appropriate for an entrance.

Bar spacing should not be modified in an attempt to make a cattle guard suitable for an animal it was not designed to contain. If different types or sizes of livestock use the same property, evaluate the crossing for those animals before selecting the guard.

Cattle guards should not be used as a containment barrier for horses. Horse properties should use an appropriate gate or another suitable barrier rather than relying on a cattle guard to contain horses.

Vehicle Traffic Matters Too

Rail spacing isn't the measurement used to determine how much vehicle weight a cattle guard can support. That is addressed by the cattle guard's construction and load rating.

Before choosing a guard, consider the heaviest vehicles expected to cross it. Depending on the property, that could include pickups, stock trailers, tractors, feed trucks, construction equipment, or other heavy vehicles.

A cattle guard should be selected with both the physical size of the entrance and the required load capacity in mind. A larger guard is not automatically rated for a heavier vehicle simply because its overall dimensions are greater.

Installation Is Just as Important as Rail Spacing

Correct rail spacing does not compensate for an improperly prepared crossing. The cattle guard also needs an installation appropriate for its design and intended use.

Site preparation may include excavation, drainage planning, foundations, approaches, and connections to the surrounding fence. These factors should be planned before the cattle guard is placed.

For the complete process, see our cattle guard installation guide. For more detail specifically about supporting the guard, see cattle guard foundations and site preparation.

So, What Is the Best Cattle Guard Bar Spacing?

The best bar spacing is the spacing specified for the cattle guard design being installed. There isn't a single measurement that should be substituted across every round-rail guard, flat-rail guard, or installation system.

When comparing cattle guards, look at the entire design rather than rail spacing alone. Consider the rail configuration, overall dimensions, livestock, expected vehicle traffic, load requirements, foundation, and installation method.

If you're planning a new crossing, Barn World can help match the cattle guard and installation components to your entrance and intended use.