I'm not a lawyer, but I own a small building materials supply company with 30 employees. If you're a plumber and work for a small company, I think it's unreasonable to ask a trade to sign a non-compete. I'm not sure how much plumbers are in demand where you are and how easy it is to find another job, but I think your boss might be shooting himself in the foot. Good reliable tradesmen are hard to come by around here.
I look at my employees as an asset and try to take good care of them and have very little turn over. I would never expect a truck driver or forklift operator to sign something like that. We probably should do something like that for our sales staff, but don't. We've had guys leave and go to work for competitors, but have only had one case where we had a guy, that we taught him the business for about 6 or 8 years, and left to go to work for some competitors. He took our customer list and repeatedly called our customers in an attempt to steal them. After bouncing around to a couple of companies, I think he's finally burned most of his bridges with false promises, but is still a stick in my britches. Most of the other sales guys that I've lost, haven't been a problem.
I think you should ask yourself some questions. Can I make it on my own and furnish health insurance? Can I find a job somewhere else? Do I like where I am now? If you sign it, and later on you want to go out on your own, they might come after you and you'd be screwed.
If you are a plumber, and thought you could leave and find another job or go out on your own and be successful, I'd do it now unless you can negotiate a solution to drop the clause. If it's what I'm thinking, your boss might be an idiot. If he's smart, and you're a good technician and good employee, he'll do anything to keep you, but you need some ammo. Hell, you never know, he might drop the clause and give you a raise.
