Somewhere down the pipe from where the washer and kitchen drain combine, there is a blockage. You will have to find where these join and look further outward for a 'cleanout' plug, then fit a snake down this plughole.
Draining refers to water falling due to gravity so you can't technically drain a washing machine to an overhead drain. However, washing machines don't really drain. The water is pumped out and up and can therefore be discharged to a drain that is slightly higher than the washing machine itself
'Do the washing up' refers to washing dishes, pots, and other kitchen utensils. 'Do the washing' refers to doing the laundry, washing clothes, and other fabrics.
The drains can get clogged and back up into each other. You can try plunging the drain to clear it, use drain cleaner or call a plumber.
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.
no that is weird
The drain is getting plugged and the toilet is lower than the washing machine drain so it is easier for the water to come up in the toilet than to go straight out the drain. Put some drain cleaner down the drain where the washing machine drains and that may solve the problem.
......before, but I would not recommend direct drain. The washing machine hose must extend up above the flood rim of the washing machine before entering the drain. If not, there is a possibility of sewage backing up into your washing machine.
None, but you could install a transfer pump to the drain hose of one.
They should not be cleaned in the kitchen sink and YES, it will harden in the drain.
Either have the washing machines pump it up Or use a sump designed to handle washing machine waste lint, volume etc
Cover the sink with washing up liquid.
The hose has to be at least at the top of the washer.