While frameless shower doors look amazing, they are water-resistant, not waterproof. You should have no problems around fixed panels of glass as they are sealed with a high-quality, mildew-resistant silicone, but around the door (and transom if you have one) they can leak with a direct spray of water. Remember, your door is frameless. We can add polycarbonate seals to help, but they will still not withstand a direct spray of water around the door and hinges. We try to limit the seals to just the bottom sweep, because just like windshield wipers on your car they are the first thing to go bad as they are plastic. We feel it is a cleaner look not to have the “plastic” seals. They can turn yellow, get moldy, and/or come off over time, but if needed, we will apply them for you.
Now I will tell you the #1 reason a frameless shower door may leak: poor craftsmanship. If the curb or dam (the part you step over) is flat or pitched the wrong direction (to the outside), I can guarantee your shower will have a problem with leaking. Here is a picture explaining:
I like to explain it as such: your entire glass shower enclosure makes up 100% of the pie. Around the door you might have a 2% gap, which means 98% of the water will be contained IF all of the surfaces that the glass sits on are pitched correctly so the water is diverted back toward your drain. Think of the Grand Canyon; water can find a way over time and gravity will do its part no matter how many seals or silicone we apply. So, make sure your tile contractor puts the correct pitch on the surfaces so the water is directed the appropriate way — back toward the drain. That will solve 98% of all leakage from a frameless shower door (assuming you are not spraying water directly at the gaps with your handheld sprayer, as that will surely leak too).