Two Drainage Questions

[Spinny]

1/ Drainage Chamber - does it need changing ?

The photo shows a drainage chamber installed by my long departed builder. The kitchen sink & dishwasher waste water will come down from the top right, and then flow out at the bottom of the photo. A drainage guy today told me it has been installed wrong and there should be a swept bend between inflow and outflow. The fall is not high and the input pipe is about 4m long. Should I get it sorted now with some other drainage issues, or leave well alone ? And what should it look like ?

 

2/ Shared Drain Manhole - If I get it replaced will I get rats ?

My drain manhole at front of the house is also fed into by the neighbours drain. Drainage guy says if I can persuade the water company they will replace it with a new one. Apparently the new ones will have a straight through outlet to the main sewer for the road, rather than the existing one which has a U / S bend with water trap (plus a plugged bypass). This makes me very nervous as we have had RATS some years ago when the bypass cap was left off. Guy claims rats can swim through a water trap (though I have yet to see one pop up in the toilet !). With no water trap on the shared manhole output I would fear a rat infestation ?

[crispy_wafer]

I’ve not seen a base like that one tbf, being pragmatic about it, if it’s grey water and it flows without stalling then I don’t see a reason to change.  Don’t understand why you’d need a swept bend, the chamber is fine as that provides a bend between in and out. 

[G and J]

You can buy a one way valve that you can pop in and it stops rats.  Amazon sells a good quality Rosshield one.   And yes, they can swim.

[Spinny]

Jeepers...scream...yes... and shit standing up for evermore...

 

https://www.express.co.uk/news/weird/1948864/woman-screams-rat-stares-up

[Mr Punter]

The chamber is fine.  The old chambers with the traps often get blocked and are not used now.  The rat blockers fitted inside the chamber work well.

[Nickfromwales]

4 hours ago, G and J said:

You can buy a one way valve that you can pop in and it stops rats.  Amazon sells a good quality Rosshield one.   And yes, they can swim.

No magic flap is inedible. It may stop them walking, won’t stop them gnawing through it; they get through concrete for context.

[Nickfromwales]

3 hours ago, Spinny said:

Jeepers...scream...yes... and shit standing up for evermore...

 

https://www.express.co.uk/news/weird/1948864/woman-screams-rat-stares-up

Time for a day off the internet for you.

[Mr Punter]

16 hours ago, Nickfromwales said:

No magic flap is inedible. It may stop them walking, won’t stop them gnawing through it; they get through concrete for context.

 

The stainless steel ones seem pretty good.  I had one fitted and it stopped the rats and has not caused blockages.  Some of them have a mechanism that allows them to be fitted fairly deep in an inspection chamber.