You have a partial blockage downstream of where the shower drain & the sink drain join into one pipe. You could try a thin plumber's snake, or add some drain cleaner, some bleach, or vinegar. About a liter of vinegar is the safest and should work well enough. Davis (davisbigelow.blogspot.com)
The sump should work as long as you have a strainer in the shower
Your kitchen sink drain and your shower drain are connected to a common drain line. There is some sort of blockage in the drain line past the point where the shower drain ties in. You need to call a plumber to run a snake through the drain line from the kitchen to where it ties in to the main drain of your house.
This can be a complicated job as the toilet drain ranges from 3" -4" and a variety of materials from Plastic to cast iron to galvanized. Then there is the venting to consider and NO a shower drain CANNOT be used for a toilet discharge as the shower drain is normally 2" diameter
The main drain is plugged. Not completely, but enough that it is easier for the upstairs water to come out in the shower and floor drain instead of going out the drain.
down the drain and into the ocean
It cant have more than 3 feet of length on it
Yes.
Snake Rivers
Shower. In a bath you have all the dirt floating around you, whereas it goes down the drain in the shower.
depending on many situations but if its still uncured cement then take a shop vac and try to suck as much as possible out then run alot of water down it. If its cured cement then most likely you will have to cut out the pipe or trap of where the cement is. If its not alot of cement in your shower drain trap and water will still flow slowly threw then you can try pouring alot of icemelt salt down the drain and it will break up the cement but takes lots of time.Very common problemDepending on how much cement went down the drain I normally use an electric snake with small chain knockers to loosen the cement from the piping walls this will NOT work on plastic system's
Clogged drains in the kitchen and bathroom can prove to be a problem. After you have tried liquid drain cleaners with no luck, try a plumbing snake. The snake is inserted into the drain and goes only a certain depth. If there is any kind of clog into the drain, it will either push it through the plumbing system or you can pull the clog out with the snake. Make sure that you are using the end of the plumbing snake that has the small hook on the end so you can easily pull anything out of the drain that may be stuck in it.