The best way of avoiding pipes freezing is to not place pipes in exterior walls. However, it is not always possible to do that.It the main floor basement bathroom, I was able to design the layout so that only the shower plumbing would be in an exterior wall.
In part 1 I described placing the pipes in the wall but ensuring the pipes were insulated well on the external side of the pipes. What I did not tell you that this wall was on the inside of an 8-inch thick concrete wall which was under the grade on the outside. It is a good bet that this area is well insulated.
The shower in the main, upstairs, bathroom doesn't have the same advantages. While the wall is six inches thick I decided to error on the side of caution and created another wall inside this wall in which to place the plumbing.
The picture doesn't show this well but the shower plumbing is installed inside of a second wall on the inside of the exterior wall. The wall was constructed on 2" x 4" lumber. In taking this approach the exterior wall must first be completing installed with the required vapour barrier - leaving vapour tabs on the top and sides to connect to the vapour barrier of yet to come insulation activities.
Other things to Note in the Picture:
- There are support studs at key locations: at the location where the shower head extends out of the wall and at the faucet
- The drain for the shower can be seen at the bottom of the picture - just barely
- The bottom plate of the shower is actually just leaning against the wall
- All the plumbing was created using copper