I agree with the above comments (wfp, don't know about trad).
Assuming you have good help the slowest part is you.Writing the slip and thinking and waiting for the custy to pay take longer than you think and 60ph is being poured down the drain every second.
Admin takes longer because their are more jobs more debts and more notes.
You need the very best kit on your van because breakdowns cost, you may need to refill earlier in the day and lose even more time. Your entire day is about how much money you are loseing.
Also it feels weird, like changing into a higher gear.After three weeks of going like a train i ran out of work.We sat there with nothing to do and i lost even more money

On the plus side the work is easier, and what used to be a record is an average day. I don't chase money as much as i used to, i'm more concerned with zero complaints, customer retention and gaining new customers.
This forum is a terrific place for picking up tips and ideas, and that's the reason i'm still on here, because it has it's annoying side too. When i ran out of work some gave very good advice, and some laughted at me for employing too soon. But i don't see how you (or me ) can physically build up the work for two people, so be prepared for slack periods.