The glued joints are a key part of keeping the root intrusion to a minimum. The PO's of our house carefully laid what apprear to have been leftover pieces of PVC drainpipe end-to-end, no glue. The pinoak had a great time sending very fine roots into the pipes and of course, clogging them. The dig up the pipe and replace project was well worth the effort a few years ago, they have been clear since.

Ironically, we have had so much rain this summer, about a foot above normal and still raining, the water levels are as high as they have ever been. The selling and buying of boats due to low water levels and deep keels is a moot point. The Islander would have caused no issues hitting the bottom. Of course, with the diesel problems, I still would have had to fix that.