Hi CS,

Don't know exactly what material. A poly vinyl combo of some sort. The reason is that it has corrugated strength on the outside and a smooth interior for better low sloping flow. Used for gravity flow applications such as your downspout drains. You didn't say if you have a somewhat level yard and long distance runs. that would be why it was used with such shallow invert depths. It can be repaired with black vinyl plastic drain tape or just a good wrapping of duct tape. It can be found at the any hardware store or the big boxers. Aloha

Never mind. It's triple wall high density polyethylene (HDPE) pipe. I found another hole in it, left by the clowns who did the final grade, so I dug up a long section and found all the markings.

Bottom line, it's about the same price as thin wall PVC, but costs less to install because the sections snap together, no cement necessary, saving labor.

Disadvantage, it's fragile and essentially unrepairable except by special mechanical fittings or pouring a concrete collar around the damaged section. Nothing really sticks to HDPE. The minimum mandatory bury depth is 12 inches for 4 inch pipe. Mine is about four inches down.

The builder saved money on labor and didn't bother to bury it at the proper depth. We have plenty of slope, so he was just lazy. I get to deal with the consequences.

Just get a piece of 4" corrugated drain tile and cut it longways on one side. Then you can snap it over the hole like a saddle. Then bury it. It's not a pressure pipe so this will be fine.

CS,

Well there you go per code. I still think duct tape will work find because of the flow pressure flow from the downspout. JMHO aloha