Please help me interpret this sewer description

[betterthanadice]

The sewer pipe which runs under my house blocked last week and I got a local company out to jet-wash it. After clearing it they put a camera down, and have sent me footage, with the following description...

"The 1st 14 metres of pipework is only serving your property. After that it becomes Thames waters responsibility as it’s a shared sewer. Looking at the footage there are several circumferential cracks in your pipe, displaced joints and the pipe seems to off dropped at 5.08 metres and is holding a water level which will cause scale to build up. Also at 8.63 metres there is loose debris within the pipe. At 14.07 metres the camera entered the manhole chamber on your neighbours property and there’s evidence of some light encrusted scale in the shared sewer. This is thames waters responsibility."

It's not clear to me whether I need to be worried by the bit in bold, so I've gone back to them for recommendations. However, it would be good to have some independent views from wise folk here.

Also, would Thames Water lift a finger to clear "light encrusted scale" or would there need to be evidence that it was causing blockages first?

p.s. I don't know whether "seems to off dropped" means that there is a step in the pipe that's meant to be there or, more worryingly, is just bad grammar for "seems to have dropped".

I think it means the pipe is at such an angle that water sits in it rather than draining away. You've got cracks going around it and some of the joints have moved - instead of being in a nice straight line, it's uneven. Depending on the causes of this, it might get worse. It isn't going to get better that's for sure. Consider getting it replaced - sounds as though it's an old clay pipe.

The above is correct. It's anybody guess how long your current pipes will last, but at some stage, sooner or later, they will need replacing. Might be a year, might be 10.

One thing I cannot stress highly enough is do not put anything except toilet paper down the toilet. If you put things like anti bacterial kitchen wipes down there (or nappies, and yes I've seen that before) they'll get caught on a crack/joint, the next load of paper will catch on that and so on... Then you'll have sewage backing up into your house in no time.

If you're careful you should be fine, just don't flush anything that doesn't dissolve or tear.