We had a 30" sink base(Schuler/Medallion), and put in an under-mount sink that measured 21" inside, plus flanges. We still had to cut away some of the cabinet's upper supports in order to make it fit. We could never have made a larger sink work with out jeopardizing the cabinet's structual integrity. I think a lot depends on how your cabinets are constructed.

Thanks svwillow1- I just don't understand how that could be the case, without seeing the sink and the cabinet together. I don't know why this is so confusing to me, can't the lip of the sink just rest on the edges of the cabinet, trimmed out so it's flush with the cabinet top?? (Using wood countertop by the way)

lynch,
Most if not all cabinets have corner braces for structural integrity and or side bracing which make the usable space for the sink smaller than the actual dimensions.
We put a sink with a 30 5/8" W lip in a 36" base (35 1/8 interior) and it barely fit. So I think your guy on Ebay is probably correct.

"For a customer"? You are getting paid to know what will and won't work? I'm sorry, but if you are being paid to be a professional on this job, then you should already know the issues involved intimately. If you don't understand those issues, then you should NOT be accepting money for this job.

What training and experience qualifies you to act in a professional capacity if you don't know the answer to this question?

Well, the "customer" is my mother-in-law- and who says I'm getting paid for it, know-it-all !!! There is nothing I can't do, and I ALWAYS end up doing it the right way, and never sacrifice quality for the end result. I'm doing a little research so that I do everything the right way and don't waste time on a sink that won't fit- as simple as that! I guess you're another know-it-all contractor that never had any questions when you we're working on something you weren't sure about?! Thanks for chiming in!

grendal_fly- thanks for the input, I'll probably just wait till the cabinets are here next week so I can actually see the inside.

There is no sin in not knowing something. That's what educational programs and professional mentors are for. You can have the safety net of a learning environment in which to make your mistakes---NOT on the job with a paying customer that expects a certain level of expertise. The moment you accept payment from a job you are obligated to actually know how to do it and to get all of the pertinent permits and insurances required to protect yourself and your customer. Accepting payment for professional services you are not qualified to do gives the professionals who ARE qualified to do those services a bad name. It's fraud, pure and simple.

If you do want to become a professional KD or GC, there are routes to becoming just that. They involve education and working under someone who has the experience and can guide you in your work until you are ready to work on your own. None of these routes involve asking very basic questions to complete strangers in a public internet forum.

Um. I think that may be a little unfair.

Let's be realistic. NO ONE know's everything about kitchen design. You could study for 10 years and still not have "seen it all". Real life experience is required because no single job is ever textbook.

This person is seeking information in order to do a good job for her client, paying or not. I know many KD's and GC that could learn from that. I'm not sure it's necessary to jump on her so much as it is to help answer the question.

Lynch,

The inside of the sink base is often functionally smaller than would appear. There is not only the thickness of the cabinet walls to be dealth with but can also be braces at the corners of the cabinet that can cut into useable space. Beyond that the sinks usually have a lip for undermounting that extends well past the bowl diameter. You can't bury that lip simply by cutting away a section of the cabinet it sits on because you won't be able to properly install the sink.

The correct way to install the sink is to make sure there is clearance for the entire lip inside the base cabinet. In a pinch I have "made it work" by creating a "wood brace" inside the sink cabinet but it's only been as a last resort. The sink base is one of the last to cut corners on for size. Particularly as you begin filling that space up with instant hot water heaters, fiters, garbage deposals, etc.

An overmount sink will often need less space than an undermount so if the space is critical switching out to one of those can save you several inches.

I hope that helps,
M.

An undermount sink normally has clips that are attached to the counter top and hold the sink in place. Therefore one needs to cut away more than just the thickness of the flange. There are kits that offer other methods to support the sink, I think Kohler makes one, but I have not seen or used one.

It is important to get a good seal between the countertop and the sink or problems might develop in the future, particularly with a wooden counter top. If it where me, I would not use an undermount sink in this aplication.