Is this washing machine drain possible?

[If in doubt...]

Hi all,

About to convert my son's garage to a kitchen / diner as below and would really like to move the washing machine in to a new mini utility as shown. The existing garage floor is only 73mm lower than the kitchen floor so basically we are looking to install 22mm chipboard flooring sat on 50mm Celotex type floor insulation. So there is only a 50mm high void within the Celotex to run roughly a 2.5 metre length waste pipe - is this advisable or am I asking for trouble? The thinking is run a straight length and punch it straight out through the external wall behind the existing washing machine position and then run horizontally across externally to the drain.

Thanks in advance.

 

[denso13]

Pushing it at 40mm pipe but you won't get enough fall on it. Unless you cut the existing floor to get enough fall?