To minimise the likelihood of sewer issues, we have the main sewer checked every six months. With that in mind, I was surprised to have a problem just a week after our check.
The photo below shows the problem – it was only shower water at this time – it did get MUCH worse.

As bad as this was, these outlets were installed some years back as the emergency overflow. Prior to that the sewage overflowed into Level 1 apartments. So it was not good but could have been much worse.
It took four visits by various plumbers at all times of the day and night to find the main problem – a pair on Calvin Klein undies!
You are kidding – who thinks that flushing a pair of undies down the toilet was going to have a good result!!
I couldn’t bring myself to put up the photo of the offending undies – here is a shot of what they looked like before their journey down the sewer

The work has uncovered some more issues with our pipework that will also be rectified in coming weeks – probably some digging in the lower carpark