We had a bathroom completely remodeled. Above the bathroom is a washing machine in an apartment. When the washer empties out, the water gurgles and spits up through the shower drain!! We get a smell also. We have to make sure the fan is on!Our plumber has tried diverting the pipes in the basement but nothing has eliminated this problem. We really don't want to have to tear the newly tiled shower apart again! Any suggestions would be welcome.

Either a drain is partially clogged causing the washing machine water to come back thru the shower trap, or the shower trap has no vent and the washing machine water is blowing out the trap seal. They may have even used the shower vent as a drain for the washing machine. A good plumber onsite should be able to quickly diagnose the situation and have a solution for the problem.

I had a similar problem with the washer in the second floor apt draining and having the un vented toilet in the first floor apt bubble fill with suds and empty the bowl after the washer drained. The plumber removed it from the stack. Put the washer on its own trapped and vented line and tied it in to the main in the basement far away from the first floor fixtures.