A.S.
My parents are in the construction industry. In fact we've (I work in the business office) been in business for 26 years. It's not standard to tip a tradesperson, the good ones don't expect it (I say the good ones because we've had some wingdingers over the years who have expected all sorts of things) and their work is something they take pride in.
That being said, if they aren't working for an employer who prohibits accepting tips, if you are truly happy with the work, a tip is a great way to say an extra thank you. Make sure though, that you're happy with the work. It's not like in a restaurant where tipping is the norm and often we tip out of feeling like it's required rather than a job well done.
Also, keep in mind that another great way to compliment or thank a tradesperson you're happy with is to promote their business. If he does a great job and you're happy, tell him so and then ask for business cards you can keep to pass along to any friends who may need work done. That's the best tip you can give because you're ultimately putting money in their pocket with new business!