Corrugated steel piping is a tremendously versatile material suited for a wide variety of tasks and structural projects, and one project it is especially suited to is building culverts. By simply bedding lengths of corrugated pipe in a suitable substrate and covering them in earth, you can create exceptionally efficient and durable water culverts, and these ready-made culverts are used widely on industrial and agricultural sites to direct water flow and improve ground drainage.
Unfortunately, while a corrugated steel culvert is a tough structure that will see many years of use, they do degrade over time as a result of the wear and tear they constantly endure. However, there are a number of ways you can dramatically extend the working lifespan of one of these culverts:
Cut your pipes to length
If at all possible, none of the actual steel piping that forms the backbone of a culvert should be exposed, as any portion of the pipe that is routinely exposed to the elements can fall victim to corrosion and environmental damage quickly. Rust from these exposed ends of your piping can also spread to affect more well-covered sections; you should therefore keep the exact dimensions of your planned culvert in mind when ordering pipes, and try to match the length of your piping with the length of the finished culvert as closely as possible.
Even if it is entirely covered, a steel corrugated pipe used as a culvert will still eventually start to rust and corrode as a consequence of near-constant exposure to moisture. This rusting can savagely undermine the structural strength of your culvert, and can cause the ground around your culvert to become badly waterlogged as a rusty pipe starts to spring leaks.
The most effective way to prevent this corrosive problem is by having your pipes covered with protective coatings before you install them. You have a number of options to choose from when it comes to coating materials, but the following coating choices are widely used and available:
- Galvanised coatings are made of a thin layer of zinc which is electrically adhered to the surface of the pipe -- this zinc naturally corrodes when exposed to by moisture, but by doing so it prevents the steel underneath from corroding also. These coatings are inexpensive and widely available, but have a limited shelf life and will need to be reapplied occasionally to remain effective.
- Powder coatings are created by 'baking' tough plastic powders onto the surfaces of your pipes, and are enormously durable. They also tend to last much longer than galvanised coatings, but they are also more expensive and cannot be reapplied once they eventually perish.
- Vinyl coatings are chemically inert and provide practically unrivalled durability, but are also among the most expensive pipe coating options out there.
Keep load-bearing strength in mind before you buy
Corrugated steel culverts, especially those used on farms, are often used as land bridges, with a thick layer of earth covering the pipe and allowing vehicles and other machinery to pass over it. However, using these kinds of culvert bridges places enormous strain on the pipe's load bearing capacity, and an culvert made with unsuitable piping can collapse unexpectedly.
As such, those intending to use their culverts as land bridges should be well aware of the load-bearing capacity of their piping before they begin culvert construction. If your chosen piping isn't up to the task (for example, if it will be expected to bear particularly heavy vehicles such as combine harvesters), you might wish to opt for piping with thicker walls. However, this can be prohibitively expensive, so you may also wish to consider scaling down the diameter of the pipe to increase load-bearing strength.