what is the standard height of a sink waste pipe ?

[mikeyw]

Hi,

I'm hoping to fall a sink waste pipe to a gulley outside the property. The pipe run length is about 6m, will i have enough fall to do this ?

Is the rule of thumb about 3" fall per metre ?

So i'll need it be 18" minimum off ground level ?

tia,
Mike.

 

[Blagard]

Hi,

I'm hoping to fall a sink waste pipe to a gulley outside the property. The pipe run length is about 6m, will i have enough fall to do this ?

Is the rule of thumb about 3" fall per metre ?

So i'll need it be 18" minimum off ground level ?

tia,
Mike.

That is an excessively long pipe run and you will need to incorporate thermal movement joints over the length.

Normal waste pipe falls are in the range 20 to 45 mm per M run. Yours are excessively steep. The range I mention is an optimum to keep any solid matter in the waste flowing with the fluids

Due to the length you should seriously consider using 50mm pipe and provide roddable access points An antivac trap should be fitted as a matter of course.

 

[GavThePlumber]

The regs state that a 40mm waste should fall between 18-44mm/metre (can be as high as 90mm/metre)

Edit: Didn't see reply above mine before posting, heed the advice, although no actual limit exists on a kitchen sink, anything over 3 meters can be trouble.