Do we tip a handyman for doing a great job at our home? What's the % or approximate tip to the labor charge

We hire professionals to refinish our old wooden floor that the previous owner left it in a horrible condition. The work included stripping the carpet, buffing, filling the cracked floor, refinish the floor, and install new baseboards & shoe moulding. They've been doing a great job so far, not to mention that they're very polite and work promptly.