Shower mixer:
If installing a shower mixer choose a mixer suitable for high pressure cold and a low-pressure hot feed valve.
Or if on full street hot mains pressure an equal mains pressure shower valve. Position the timber for the screwing off of this mixer about 3 foot 3 inches (1 meter) off the floor to the left or the right of center of the shower tray nearest to the opening of the shower door.
The instructions for the shower mixer will give the measurement from the finished wall back to the face of its fixing timber.
Now place another noggin center of the wall measurement of the bath end or of the shower tray wall at 6-foot (1.8 M) above the bottom of the shower tray.
With the face of this noggin back the depth of the wingback from the finished wall surface.