Macerator Install and Using Existing 40mm Waste Drainage and wastage systems and plumbing help, advice and answers

[stevewah]

hi al can you install a macerator and use an existing 40mm waste pipe serving the bathroom as adding a loo to the room and soil pipe is on back of house . there is a kichen on the floor above that also uses the same 40mm pipe would this be ok to do if I added an Air Admittance Valve to the high point of the 40mm pipe in kichen thanks

[stevewah]

could I add 40mm Non Return Valve to bath and kichen feed in to this 40mm pipe