If you've noticed water leaking from the sides of your frameless shower door, you'll need to take action to prevent further damage. Investing in a side seal for the door is the best way to stop the leaks. You'll need to remove the old putty and apply new putty to the inner edges of the frame, where it is attached to the walls and bathtub. Make sure that the drain holes are not blocked by putty. If you want a completely watertight seal, consider getting a semi-framed shower door.
Removing the frame is what causes water leakage since the glass is not completely sealed. If there is a slope issue, this could also be causing water to escape. By design, any water from the ground will be expelled to the ground. To ensure that your shower door is properly aligned, use a silicone gun to draw a low, clear line on the shower floor when it's closed. This will help you identify any misalignment that could be causing water leakage.
Frameless glass doors and flat entrances to showers are more likely to cause water damage. If you have a fixed-panel glass shower with a single fixed panel, you can use a side seal to fill the space between the two panes and prevent water from escaping. If you find that your putty is no longer secure, it may be seeping past it. To identify where water is leaking through, turn on the shower and watch from outside. If you have tiled showers, watch out for water damage on the outside of the shower door. This could be due to an installation error.
Run your hand over the edges of the shower door to feel for moisture escaping from inside. To learn more about seals for shower doors, watch this helpful video. If you need parts for your shower door, there are many websites that offer them. For detailed instructions on how to measure and install any of these solutions, watch this YouTube video from Dulles Glass & Mirror.