Shower room plumbing advice: wastes

[JKBDIY]

Hello,

Seeking a bit of input on my shower room renovation.

I need to set a waste for a new shower and a bathroom sink.

I'm attaching pics of existing wastes which used to serve a sink (the vertical, capped line from the photo) and a washing machine (the horizontal, cut line from the photo). The new shower tray would sit directly over top of where these two wastes currently sit.

My first instinct is to ignore the one that is currently capped and to put the sink and the shower into the other line by addition of a 'wye'.

I've made a very crude attempt to illustrate my plan here in MS paint by showing the WYE as the red blob, the line running from bottom left to WYE the sink waste and the line from the circle to the WYE the shower waste.

Any thoughts on suitability here? Both runs would have sufficient slope.

 

[Madrab]

Keep them separate - run the shower waste in the vertical (maximises the drop) and run the basin waste into the horizontal. That way neither interacts with the other under normal use.