Is it a problem - drainage without trap

[pragms]

Hi,

First time poster, I apologise that it has to be a question...

I'm having my patio relaid and the builders have replaced the single naff drain with a strip of Aco along the lower edge, so far so good! The problem is that it looks (or sounds) like they have just dropped straight onto the pipe which is a combined drain as we don't have storm drains just combined soil/surface.

I say sounds as you can hear the water from a toilet flush if you bend down near the drain.

My question therefore is... is this likely to cause a problem longer term (we are first on the sewer run if that makes a difference so nobody else's foul matter runs past us).

Should I insist they rip up the newly laid patio to put some kind of trap in?

Is there something that can be retrofitted into the Aco outlet from the top that would be like a one way valve?

TIA

 

[John D v2.0]

Yes, the drain ventilation should be 900mm above any window or door within 3m of the ventilation point. If that's at ground level then it's not likely to be met
However f it's a new drain maybe there is a trap but it's just dry still?

 

[pragms]

Thanks for the reply.

It might be ok then as it is a good 6+ metres from the house. It's definitely not dry as there's been lots of water put down it.

 

[Nige F]

The builders should not have done that - they should have taken the aco drain outlet to a soakaway.

 

[John D v2.0]

The builders should not have done that - they should have taken the aco drain outlet to a soakaway.

Agree, if the ground is suitable for a soak away. In our area building control accept draining to the sewers purely because the ground is clay so not much will soak away. I'm not sure the rules about increasing the amount of runoff though.

 

[pragms]

It is clay ground and draining into sewers is the most suitable. It was just the lack of a trap. But given its 6ish metres from the house is it acceptable.

It would involve pulling up a lot of flags to rectify.

 

[John D v2.0]

In my opinion it's not acceptable but i can't be bothered to trawll the regs to find where.
Also as i say there are also restrictions on increasing the amount of run off into the sewers, but ii think they mainly are enforced by the planning system. So councils don't have many ways to restrict things.

 

[Ian H]

I'd want a trap to stop the smells venting and also to catch silts. It wouldn't need much pulling up, probably a 600x600 bit to take the bend out and put a trap in.

 

[^woody^]

All combined drains should be trapped