On Jul 8, 10:53*pm, David Nebenzahl wrote:
When the subject of running downspouts inside walls came up here some
time ago, I thought the consensus was that it was a Bad Idea. Pipes
leaking inside walls and such.

I think Tom is assuming that sewer-grade plumbing would be used, not
typical downspout crap. With how easy it is to assemble and glue PVC
or ABS, this is a very reasonabe assumption.