Horse float repairs and building: a guide to using plywood

When constructing or refurbishing a horse trailer, the material choice for the walls and floor plays a very important role in the safety and comfort of animals.

Plywood is often the preferred material for horse floats in Australia, and for good reason. Being naturally strong, plywood can withstand the constant movement, and wear and tear associated with transporting horses. High-quality plywood solutions are resistant to moisture, rot, and fungal damage, ensuring the trailer lasts for many years.

Right Plywood for Horse floats repairs

Type of Plywood

• Exterior-Grade Plywood works well for structural parts of the trailer that won’t be exposed to direct moisture. In Australia it's often treated with adhesives that make it suitable for the internal walls and framing.
• Marine Plywood is a best bet for areas that are directly exposed to moisture, such as the floor or external parts of the trailer. This type of plywood is specifically engineered to resist water, rot, and decay making it very useful for trailers that need frequent cleaning and exposure to wet conditions.

Plywood Thickness

• For the walls of the trailer plywood with a thickness of 12mm to 15mm is recommended. This thickness range provides enough strength to protect the horses and keep the float lightweight and easy to handle. For larger horses, the higher end of that range is better, and perhaps even consider going closer to 18mm for the walls if the float regularly carries multiple animals.

• The horse float flooring solutions support the full weight of the animals, the material must be reasonably thicker (18mm to 25mm). It offers maximum impact resistance, ensuring the floor can handle the heavy weight and movement of the animals. Also, consider adding a reinforced timber frame beneath the plywood sheets to ensure there’s no sagging or excessive wear in the long term.

• For internal dividers, 9mm to 12mm plywood is typically suggested, provided it’s properly supported and secured. While 9mm to 12mm plywood could work for internal partitions, experts recommend at least 12mm (if not thicker) for dividers, especially for more active or larger horses to keep them securely in place without flexing under pressure. If the horses are pushing against them or if there’s any force from sudden movements, thinner plywood may not offer enough strength.

Grading, Finish and Non-slip properties

Higher plywood grades as A/B or B/C ensure the plywood is strong and free from defects. While the surface does not need to be perfect (since it's going to be sealed and painted), the internal layers should be solid and free from imperfections. A high-quality protective finish, such as a varnish or sealant, should be applied after the installation.

While protective coatings are essential, it's worth noting that the sealant used should be non-toxic and safe for animals, as horses meet the walls or floor regularly.

For the horse float flooring, the plywood is often secured firmly to the frame using corrosion-resistant screws or bolts. To further safety enhancing, a non-slip coating or rubber mats over the plywood floor can be laid. Keep in mind that while rubber mats are a good idea for added grip and to reduce wear on the plywood, non-slip coatings may not be necessary. Some non-slip coatings might wear off over time, especially with the movement of horses and cleaning. Also, the mats are easy to remove and clean, which is crucial for hygiene.

Regular inspections are critical. Check the floor for any soft spots or damage from moisture, particularly around the edges where water can get in. Inspect the walls for cracks or loosening fasteners regularly, especially after long trips. Over time, the plywood sheets can weaken, and any damage should be addressed promptly to avoid reducing the safety of the animals inside trailer.

Important Considerations

• Be mindful of the overall weight. While marine plywood is heavy and durable, too much weight can place unnecessary strain on the float’s axles and hitch, potentially making it harder to tow safely.  Ensure the weight is distributed evenly throughout the trailer to maintain balance and avoid stress on the axles and wheels.
• Proper ventilation in a horse float goes far beyond just having open windows or vents. Cross-ventilation is important for preventing the trailer from becoming too hot or stuffy, particularly in Australian summer. Installing adjustable vents or slatted side panels that allow airflow while keeping the horses safe is something to consider.