Proper Slope on Shower Threshold
Proper slope on your shower threshold or curb is imperative when planning the installation of a frameless shower door. We install frameless showers with the least amount of metal and seals to keep the glass looking clean. When installed correctly, water will shed down the glass door, land on the sloped curb and shed towards the drain and not onto your bathroom floor. Remember that water will travel in the path of least resistance. Thresholds should to be slanted inward at a 5-degree 1/4″ pitch or slope so water flows toward the drain. 
Zero Entry Curbless Showers
New trends in bathrooms are to install showers with ADA or zero entry floors. Unfortunately the industry has not figured out how to install shower pans with adequate slope yet. Most of the zero entry showers we encounter have no slope towards the drain at the door location. Water sheds down the door, hits the pan and should run into the drain. With no slope, the water can puddle on the bathroom floor.
If you are thinking of having a zero entry shower installed. Make sure you have a candid conversation with your tile setter prior to starting your shower pan asking if they can provide proper slope.
No slope and shower pan higher than floor.
