buts thats ok saying they do £200 worth of work a day adn tehy make £55, but what stops them from thinking i can do this and earn it my self
Whats stops anyuone thinking this about anything?
Some people don't want to run a business and it's not everyone that can get in really good solid work, which is what you need before you take on staff.
Gazza, if you don't mind me saying, you sound negative about taking someone on and I'm not sure you are ready. If you think more positively then you may just win the lottery of staff

At the end of the day or interview....if you are not happy then don't employ, that's your right.
If you think they will be ok:
Start them on a trial basis, with a trial basis wage and the promise of,if satisfactory after trial basis, you will go on to the standard wage and terms. You'll soon know if they are right or not,.....
Holidays, as an employer you can determine when paid holidays are taken....simple, when you want a holiday, have a "shutdown" period if you don't fully trust what will go on if you are not there.
You get extra done the 2 weeks before and the week after you return.
Profit to be made, if you have calculated all your costings etc correctly then of course you will make a profit money wise, but remember profit is not all about money, it's about not having to work so hard yourself, sleeping at night, a good lifestyle, feeling stress free and so much more. If you don't get stressed now you will do with staff whether they are good, bad or indifferent.
Personally if you have the workload and you want to expand I would say go for it, times are hard for people and there are some really good people out of work, you never know you may just hit the jackpot first time and bag yourself the best worker anyone could find.
