Apply the adhesive in short zigzags or waves.
Gluing plastic sheet to wall.
Contact adhesive is the industry stander for gluing formica to drywall.
Adjust the sheet until it is level and draw a plumb line across the top either on the drywall or right on the.
Wait 3 to 5 minutes for the polishing compound to set.
Apply construction adhesive to the wall.
Usually there should be two coats applied before sticking the mica because drywall is somewhat porous.
Clean the surface of the plastic to remove any grime and dirt using dish detergent and warm water.
Place the first sheet against the back wall of the shower and set a level on top.
Rub the compound onto the surface of the plastic a circular motion.
Hold the plastic up over the wall you want to cover and use a utility knife to cut around extrusion such as windows and pipes.
Apply a small amount of polishing compound to the plastic according to the label directions.
Hold plastic sheeting up to the wall and press into place when properly positioned.
Start at the top of the wall and work over then down both pressing pulling and smoothing as you go.
Before working with any kind of plastic be sure to put safety first.
The glue should be applied with a sprayer paint roller or brush.
Here is more detail about what kind of glue to use on formica.