Decide what material will be created, protecting the border: border tile or plastic area. They differ not only in terms of price, but also by way of gluing. And though plastic corner will cost much cheaper, it is not able to provide complete protection from water penetration.
Prepare a working surface to which is glued a protective border. Remove the old putty or sealant, cleaning the surface with a knife. Since a bathroom is a room characterized by a high level of humidity, be sure to perform surface treatment of the wall antifungal liquid. Then allow to dry the surface (in order to speed up the process, use a hair dryer).
Perform precise measurements of the bath. If the choice fell on the plastic corner, put on it the desired size and cut with a hacksaw. Remember: plastic parts among themselves will need to stitch at a 45-degree angle (to make it easier, using a mitre box construction). Then attach the prepared plastic corners to the work surface and check to see if they fit. Apply on the surface of the plastic corners which are adjacent to the bathroom and the wall, a little silicone and apply a border to the working surface. Press down and hold. At a distance of two millimeters from the plastic bracket attach to the wall (on top of it) masking tape, then same procedure will follow and the bathroom. With a gun enter additional silicone in the joints and bath area, wall area, and also the two corners. Remove the masking tape.
Tile border glue on the silicone and exclusively to wall surfaces: on tile to keep it will not, therefore, the tile has cm by 1.5 to reach a bathroom. All trim tile border complete grinder. As a tiled border, you can use cut tiles. Cut into strips of desired shape and size and glue them to the glue-cement. Perform the grouting. Although this method and will not cause delight connoisseurs of aesthetics, but will provide reliable protection against the penetration of water into the gap between the wall and bathtub.