Toilet + Shower in same downpipe

[russ8585]

Im replacing the bathroom in my new house and found the toilet and shower share the same downpipe. The basin runs to a different stack.

I used to do some plumbing when I was younger and I've never seen this setup. It seems a bit unhygienic. It's an older house so the waste and rainfall downpipes will share one sewer in the street, but I still feel the toilet and shower shouldn't be connected like this. A back up could cause sewage to flood the shower before the toilet (those in theory if it all runs to one sewer in the street, this may not matter).

Should I move the shower waste to another downpipe (basin is using the old bath waste) or is it a waste of time and money?.

 

[denso13]

Should I move the shower waste to another downpipe

No, it's perfectly normal.

 

[oilhead]

I think if that downpipe backed up to the shower level you'd know it before fooding the shower.

 

[Exedon]

As above all normal
It's called single stack.
Pic of one i did this morning.