Fittings for shower mixers and slide rails:
Mount your shower mixer so you have a little room to place a loose-coupled nut ½-inch (15 mm) poly elbow on the hot and cold entry points on the mixer. If you are using a fixed shower spray rose head then simply place a straight loose coupled poly adaptor fitting and pipe up to the female wingback placed flush with the outside finished wall surface 6-foot (1.8 M) above the shower tray.
If fitting a slide rail do not forget to place timber in the wall cavity to take the screws of the rails connector sections where they go onto the wall. NOTE: Check the amount of offset on the shower rail and its spray head to gain correct placement of this timber fixing.
Also note: It is good plumbing practice to take your mix lead off the top most mixer outlet and run it 2-feet (500 mm) in the air up into the wall and then turn and come back down with elbows to the lower down position of the slide rail female wingback near and above the mixer. This is to create another mixing section before it enters into the shower hose.