Wally thats how people expand to other branches of cleaning, sometimes it works and sometimes its a costly detour from what you are good at.
I used to pressure wash, carpet clean, paint shop fronts, buy and sell shop fittings pretty much about everything to earn a crust.
Now, all I do is clean windows, cos that is what i'm good at and it costs me nowt in plant or hire and I don't leave my normal work to do stuff that may or may not work.
Good luck with your efforts, not for me, but then if no one was to speculate the world would be a boring place.
Steve