Hi Richy,
The first thing I do when I take on new staff is be perfectly straight with them regarding what I expect from them whilst working for me.
It takes a long time to build a solid window cleaning business, but only takes a short time to lose it.
As a boss you have to be fair, and your hourly rate of pay sounds ok to me, do you pay bonus at all ?
I would never pay my lads personally for hitting targets, as I think work would be rushed, and all I say to my lads is just take your time, do a good job, and take NO risks, and that way I know the work will be completed correctly (fingers crossed).
When I can see this happening, I do that bit more for my lads and look after them and give them a bit more to keep them happy working for me.
I make sure the equipment they use is quality, so they are happier whilst working.
The first time you notice or believe they are taking advantage of your better nature, YOU MUST SORT IT IMMEDIATLY.
Regarding your question as to how many jobs should be completed by your lads, only YOU will know.
I am not bothered how many jobs anyone else can do, I am only interested in what I believe is a fair days work for my lads, as everybodys targets are different.
You have to toughen up, just get a couple of lads that are good (difficult I know), manage them correctly, then when you need more staff split them up and let them be in charge of their team with the new lad, they will appreciate you for giving them the responsibilities.
Don't forget, don't expect too much, make sure you price correctly, and don't make them feel rushed, as that's when accidents are more prone to happening, and you do not want that.
Any advice or someone to try and help you, give me a call and your welcome to come for a coffee.