Advice on drainage for blocked 2nd story toilets/drains

[Maverick-83]

Needing some advice for recurrent blocked drains in upstairs toilet and sinks/shower. I’ve tracked the drain to under the house and it looks like there’s some convoluted plumbing done by someone - p traps and not sure if they’re correctly installed.

We clear the blockages with draino but they keep happening. Can someone tell me if these drain pipes are done correctly (we’ve only recently moved in). I’m not a plumber but just needing some advice on whether I need to get someone in to fix. Thanks

 

[Deleted member 120897]

One seems ok, the other looks a complete bodge. It wouldn’t explain why toilets are blocking up though

 

[Ben-gee]

In answer to your question, yes you do need to get a plumber in to sort that out!
The shower is clearly a bodge and will be much improved by configuring the drain better and using a conventional shower trap that can be cleared from inside the shower enclosure.
Get the plumber to check falls on the toilet drains too, as someone that does a bodge like that shower does not point to being a careful worker!

It also looks like the shower tray has been laid directed on the joists, this is not good practice. From below you could infill between the joists with 18mm ply pushed up and then held in place with screwed battens.