If your floor or carpeting gets wet near your sliding patio door every time it rains, there is a little maintenance procedure that might help.
Your sliding patio door actually "rolls" on a raised center track. On either side of the track there are usually "walls" at least an inch high. An inside wall and an outside wall. The outside wall should have "weep holes"... little slits at the bottom of the wall several feet apart. These weep holes are to drain the water in the track when the rain cascades down the glass.
These weep holes often get clogged with dirt and leaves requiring periodic cleaning. Sometimes, an over-zealous contractor may have accidentally "caulked" closed these holes during an effort to tuck point or provide external weather sealing.
Get a pipe cleaner, coat hanger, popsicle stick or just about anything else that will fit through the weep holes and clean them out.
Once clean, you should be able to pour a small pitcher of water into the track and watch it migrate to the weep holes and trickle outside.
Older tracks without weep holes may need to have some drilled. They do not need to be larger than half the diameter of a pencil.