I think most of us are not talking about a lot of pipe here so spend just a few dollars more and be happy. My nephew did his with the PVC ran above the ceiling on top of the walls with drops. I ran mine with Galvanized and now I think he wish he had. Nephew used it because it was easy and quick to put together but with a little planning galvanized is a snap to. I used 10ft sticks around the wall with a quick connect at the end of every drop. It went quick and I really like it.
