I installed a drain as part of a bathroom renovation that required a city permit. Surprisingly, I got the wrong advice from several plumbers that I could just drill the right size hole in the wall, run the pipe, and be done with the move. Upon further study, however, I realized that if the hole was not properly reinforced to the size I needed, I would be breaking the rules. The solution was the Simpson cleated shoe. The shoes are very easy to install and require 12 nails. The correct nails are 1.5 inch, 9 gauge nails that I purchased from Home Depot. I've found that the best tool for driving nails in tight spaces is a nail hammer. without delay.