Culverts are available in double-walled plastic. Plastic culverts come in 20' lengths, with a bell on one end and gasket on the other so no additional band is needed to connect multiple culverts. Though a band is available if needed.
Double-walled ADS plastic. Smooth inside, corrugated outside.
Available in: 10' or 20' lengths
A split coupler to join two pieces of culvert together.