Plastic pipes look superior - no corrosion, lightweight, easy to install, a bit flexible. Yet there're lots of cases when culverts and drainage pipes are made of steel (corrosive) and reinforced concrete (very heavy).

What can other pipe materials do that plastic cannot in drainage and culverts?


Although it doesn't corrode in the same say that steel does, plastic also degrades over time. The common corrugated steel pipes are galvanized, so take some time to corrode.

Concrete is usually used to support larger soil pressure from the outside. Corrugated steel pipe can sometimes get squished by the pressure of the soil, especially when it's a bit unstable and the pipe is buried deeply. For large diameters, concrete is cheaper, especially the deeper it is buried.

Another issue to consider especially for small shallow culverts is that light is actually a liability. When the soil acts like a very slow-moving fluid, light pipes rise over time due to bouancy. You can sometimes see this where a corrugated steel pipe was buried only a foot below the surface of a dirt road. After some years, the top of the pipe is at the road surface, where it gets damaged by the traffic.

  • 2
    $\begingroup$ plastic also degrades from sun exposure $\endgroup$
    – Netduke
    Jun 3 '15 at 14:06

PVC pipes for outdoor sewerage systems are intended primarily for buried gravity sewers and industrial wastewater.

You will need cast iron and grates that covers and protects the equipment. Also for the efficiency of drainage, channel drains are very effective and safe, especially made from stainless steel.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.