May have missed other replys so........
Use a SonaTube thats large enough for your needs.I put one in my house
20+years ago. No problems with moisture as every thing just ends up in the
basement..... ohhohh/// laundry room.

"Phisherman" wrote in message
...
I'd recommend building it from MDF and lining it with galvanized
metal, making sure all seams are smooth. The edges can be soldered.
Or, you can line the tube with vinyl flooring. Drywall won't hold up
to wet towels.