Thanks, all, for your time & efforts adding to the article & comments, especially Dave urging requesting both General Liability AND Worker Compensation insurance certificates to protect from real & fraudulent liability--from my experience especially in California, where insurance fraud is a popular income thief, even causing car collisions to collect.
• One room or the whole house? Applying one coat in one room is a reasonable DIY Saturday project (especially if you have help and beer). Multiply the time spent moving furniture, prepping walls and sanding old trim by the number of rooms in the house, and you might want to hire real help. It's the same outside. You can probably tackle one shady garage wall that needs a little scraping and sanding plus a coat of paint, but covering all surfaces of the house is usually best left to a pro.
I've seen this done many years ago by a guy who did all sorts of jobs where I lived. My dad caught him painting his boss's roof and he was watering down the paint. We've had a hard time trying to get a painter for our house. We've had a guy that had been remmended by a neighbor and he hasn't showed up to paint for 2 weeks. I want to call him and my husband says no. I'm 69 years old and I'm about ready to go and paint our 2 porches, I've painted all my life and all the inside of our home. Maybe that's the way it should be with everyone that can paint pretty good.
I had florida home painters paint my tri level. Joe is a nice guy and owner who quoted the job. He was very helpful and gave us a paint sample book to choose from. He help to suggest colors for the patio floors which was a nice compliment to the color of the house. His crew was fast and clean during the painting process. They used quality sherwin Williams paint the whole experience was great i would recommend checking them out for a quote
With that said, here's the reality of that particular scenario. Painters do put water in the paint, but not for reasons you would think. Some materials need to have their viscosity manipulated in order to slow drying time, allowing gravity to 'smooth' out the product for a better finish. It also prevents 'drags' and 'sausages'. I personally try not to do it too often, but from time to time I have to. I want my client to have a proper finish.
I used to work at Sherwin Williams. The best thing to do is specify that you will purchase your own paint. If the painter objects strenuously, he was plaanning on making money in the ways this article outlines. You might pay a few dollars more for paint, but you will have control of the quality of what goes on your walls. Never skimp on paint quality.