Some over-bath shower screens can be fitted by a competent DIY user, but careful installation is important. The wall profile needs to be level, securely fixed and properly sealed to prevent leaks. You will need to drill into the wall, which may involve tiles, plasterboard, masonry or other surfaces. The bath edge should also be checked for level, as a poor fit can affect the bottom seal. Glass panels can be heavy and awkward to handle, particularly thicker or hinged designs, so a second person is often needed. If the wall construction is uncertain, or if the screen is large, frameless or expensive, professional installation is usually the safer option. Poor fitting can lead to movement, leaks or damage to tiles, so it is worth taking time to assess the job before starting.