underground drainage

[spookyspaniel]

on checking my underground drainage, before i have a conservatory built over it , i find all the salt glaze has split, so i'm going to replace it with plastic 110mm.
Wastes into drains are x1 sink x1 dishwasher x1 washing machine.
By the bungalow i want to put a gulley trap. Do these have rodding points already in or will i have to buy these seperate ? the reason i ask is that the original drains are only 9" under the soil at this point.
Do i have to lay the new pipes on shingle or can i lay them in the original pipe trench on the soil ?
I then have a 6m straight run into a 90* bend, will i have to put a chamber or rodding point here ? at this point its only about 13" deep. from there its a 3 m straight run which goes into a newish plastic chamber
When the conservatory dwarf wall is being built will i have to put the pipe in a sleeve of some sort or will they put in a lintel over the pipe.?
Finally will any pipework need to concreted in place ?
sorry this is a bit long winded but i've had two quotes to do the job of a £1000 and thats with me digging up the concrete paths and old pipework, which i cant afford, hence why i need advice.
many thanks

 

[ChrisR]

There are lots of different gulleys, some with traps.
If it's buried I'd use 2 x 45 rather than 1 x 90º.
Lintel over the pipe.
Pipes supposed to be laid on pea shingle but most builders don't bother.

Others know more than me but they don't seem to be about...

 

[brumylad]

you'll need to involve the building inspector of the local council for that drain work so you could ask him.

I would put a rodding access fitting separate to any gully at the start of the first run. At the 90 bend put in a shallow access chamber, plus a short pipe run rising up to the surface to a rodding point coming off the side of the access chamber opposite to the last run, so the chamber is acting like a T.

 

[spookyspaniel]

you'll need to involve the building inspector of the local council for that drain work so you could ask him.

I would put a rodding access fitting separate to any gully at the start of the first run. At the 90 bend put in a shallow access chamber, plus a short pipe run rising up to the surface to a rodding point coming off the side of the access chamber opposite to the last run, so the chamber is acting like a T.

I was hoping you were'nt going to mention HIM... and the first run is only13" from the gulley to the first bend before the 6m straight run. This is because i only have a strip 3' from the bungalow by 13", (which will be paved after the conservatory is built)as i'm just replacing the original saltglaze pipes can i involve HIM... when they dig the footings out for the conservatory or do i have to have him check it first, cos he would'nt know its been changed, unless he reads this forum... ooops.
anyway thanks for what youve told me already