Bathroom Sink drainage question please

[Tim_Quincaillerie]

Thanks

 

I am plumbing my sink in the bathroom now and have a slight query.

I am using 40mm piping for the drainage and have a situation that the drainage will run 2.3m along the outside wall and then turn 90 degrees into the partition. whats the norm for the fall of the pipe. I have heard it is 10mm in 300mm is this right?

 

Can the fall be increased?

 

Thanks

 

Tim