I'm thinking about putting a sink in my basement, problem is to get a downward slope to the drain pipe I have to go up ~28 inches from the floor. When you add the P-trap distance up, would that make the sink too tall?
I plan to use it as a wet bar. So just a small sink for washing out glasses and washing hands, dumping out drinks I guess.
It all depends on the use of the sink. Typical counter height ranges from ~ 30 inches to 36 inches. In bathrooms it is typically lower - 30 - 32 inches, but 36 inches is standard for kitchens in the US (dishwashers and slide-in ranges are sized based on a 36 inch high counter). A sink can even be a little higher, though above 36 inches a sink can be harder to use for shorter people. A lot also depends on the use - washing hands is different from washing big pots & pans.
Figuring on a bar sink with a depth of 10" (from a quick search, but I think that is typical), and adding a few inches for sink drain, coupling to trap, etc., my guess is your counter height (top of sink) should be somewhere in the 42" - 46" range. A quick search shows typical wet bar height at 42". That is really for the part between the bartender and the customers. The sink area behind the bar can be lower, but at least that gives a basis for a 42" height. A shallower sink (~ 8" instead of 10") would definitely help too.
If you are getting a plumber to do the work, I suggest you have them review the design before you purchase cabinets, counters & sink. If you are doing the plumbing yourself then come back with more specifics once you have a planned design and one of the experts (I'm not a plumbing expert) can review in more detail.
Assuming you are going to have 36” counter height. I think you are fine based on this from SFGate home guides
The most common kitchen counter height is 36 inches, but it can vary from 30 to 45 inches. The standard kitchen sink is 8 inches deep, which means that the normal distance between a kitchen sink drain and the floor is 28 inches. This will vary, depending on the height of the counter and the depth of the sink bowl. In the bathroom, the sink drain is typically between 24 inches above the floor. This measurement is based on an average bathroom counter height of 32 inches and a drop-in sink with an average depth of 8 inches. Rough-in plumbing is usually placed at a somewhat lower height, between 18 and 20 inches, to accommodate varying counter heights and sink depths and leave plenty of space for the P-trap and necessary connections.
