Soil pipe question ??? Help

[Ellis]

Hi All
please can someone help?

Having a new downstairs Wc added in the double garage having a section stud walled & floor raised to kitchen height, suspended floor will run soil underneath

I need to have 5m horizontal soil pipe run to reach the stack that sits in garage is a gradient of 90mm ok??

Can I add boss adaptor about half way for washing machine & sink??

can this just be branch pipe? The current floor concrete may have to be Dig about 3 inch around Stack to allow me to add brach connection is this ok and should it be in grey fitting ? Or what fitting ?

really appreciate any help ?? New to site so hope put post in correct place

thanks
Ellis

 

[MSM]

I think 18 mm fall in 1m is bare minimum.

 

[stevetheplumber]

You will just about get away with that but i would ensure you have some access just in case it blocks in future washing machine will need a trap with an aav on it its will not be to standards but sometimes you need to bend the rules a little

 

[Ellis]

Thank you