adding new toilet downstairs, vent pipe or no vent pipe

[kotewala1]

Drainage
1. new down stairs toilet against outside wall . Pipes had be at outside at side of house. Builder put them almost on the surface, saying if he puts them deeper they will not connect at other end into the inspection chamber. Is this acceptable? I now cannot creat a path eg blocks, slabs, tarbac etc. No nearby vent pipe . Does it need vent pipe outside ? If no vent does it need AAV? if so can AAV go on the outside and where ?
2. Upstairs toilets , does every toilet and every WHB need a direct link to the vent pipe outside? Plumber is saying no . He said no AAV is not needed upstairs as toilets link directly to soil stack on the outside . The plans and Bregs did say AAV on each toilet but Plumber .
3. does the kitchen sinks need to connect to vent pipe

thanks

 

[blup]

Soil pipe needs the gases venting, basins need aav if not connected to soil pipe. There must be a minimum depth to bury soil pipe, 100mm minimum iirc. Where does the existing wc connect?

Blup

 

[Dereekoo]

No need for vent pipe if your drainage system is already ventilated. No need for AVV on basin either(I assume this has U bend and connected to toilet soil pipe) . Toilet floor level must not be more than 1.3m above IL of outside drain. Your existing inspection chamber must be quite high or far away to require the pipe to come out the ground as it does, perhaps he could have laid to a lesser gradient but it looks to be minimal anyway

 

[kotewala1]

Thank you to BLUP and to Dereekoo for your reply. The first floor Basins are connected to the soil pipe as shown in pic Black pipe connects to soil stack . I do not think it has a U bend plz c pic. Should it have a U bend ?
The ground floor new toilet is connected to new soil pipe as shown in previous pic. Does this toilet need AAV or air vent vent pipe on the outside wall as it it too far from the existing air vent pipe. Secondly to be sure as I understand your replies, plz correct me if I am wrong , each Basin Must have U bend AND be connected to soil pipe. If Basins are NOT connected to soil pipe and do not have U bend then each Basin MUST have a AAV ?
Thank you in anticipation

 

[Dereekoo]

Its got a bottle trap so no problem and I assume you mean connected to stack/vent pipe. If new floor is 1.3m or less above external drain IL toilet does not need to be vented or AAV. All basins required water trap (bottle or U) to prevent odours coming back. Basins must have a water trap whether they are connected to the drainage pipes system or direct to external gullies, Basins are unlikely to need AAV unless their discharge pipework is outside normal parameters (see diagram 3 of Approved Document H - Drainage and Waste Disposal)

 

[denso13]

You could run it past your LABC, they'll have to ultimately sign it off.