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Obstacles When Trying to Replace a Kitchen Sink

We are contacted numerous times a week regarding replacing a sink in an existing counter top. People have various reasons to want to change the sink, such as :

  • Moved into a new house and hate the sink. 
  • Found a new and improved option that better fits their needs.
  • Sink became damaged, worn out, lost color. 

Often, when someone is trying to replace a sink, they are trying to switch from a double bowl to a single, or an old cast iron sink to a stainless.

***Let me save you some reading time. Most of the time - and by most, I mean 99.9% of the time, we can't help. We want to, but can't. We have tried hundreds of times. ***

We know the differences between manufacturing methods, Installation methods, and sub-sets of the construction end of your Kitchen. (We are also Cabinet Designers - DirectCabinets.com)

Let's run through an example of what we face with trying to assist you, and what you face with this search..

Example :

Client : " I have a 50/50 double bowl sink. It's undermount. I want to change it to a single bowl. Can you help me find something? "

 The realistic answer is, unfortunately, No. There are too many variables to account for that would be needed to have an undermount sink fit an existing hole.

- The Variables -

Introducing the Corner Radius

1. Kitchen sinks have various designs with regard to the radius of the corners. Generally, we refer to three; Standard, Small, and Zero

 

These three variations of the corner radius will often also be seen on your existing countertop cut out. The exception is that a Zero Radius Sink might have a small Radius counter top cut.  This depends on the strength of the counter top, the tools, time, experience, and skill of the counter top fabricator. Generally speaking, a zero radius cut in the counter top is more difficult to fabricate and can, not always, create a weaker area in the counter top.  

 Long Story Short: The Radius of the sink you are searching for needs to be extremely close to the one you want to replace. If it does not match well enough, the sink will look odd, or "incorrect", in the counter top.  

 

Next up: The Reveal

What about the reveal in your counter top?  Wait. What? 

The "Reveal" of the sink indicates how the counter top was cut compared to the sink mounting flange. To rephrase, the reveal can be described as how much mounting flange is seen in the counter top cut out. Three types exist; Positive, Negative and Zero. 

Sink mounting reveal

Why does this matter?  Aside from how the sink would look installed, the reveal affects how the sink is physically installed. When installed per manufacturer guidelines, undermount sinks are secured using mounting clips. 

 These mounting clips, along with how much space is between the edge of the cutout and the sink flange, the size of the mounting flange itself, and the 

Mounting clips are drilled into the underside of the counter top, holding the sink by it's flange and secured. 

 All the elements mentioned so far will affect where the mounting clips are located. This affects where the anchor drill points are located.

Hypothetically, if you found a sink that matches sizing and radius, it is still possible it can't be installed without causing excessive anchor and drilled holes in your counter top. Anytime a hole is drilled into a stone countertop, it's possible the stone can crack.  The more holes, the higher chances of a crack. Secondly, the closer the holes, the chances of a crack grow exponentially.

Before you ask, or, if you were told it's an option, we absolutely do not recommend securing an undermount sink to a counter top using only glue, silicon, or any other type of adhesive. 

This will often be a reason a stone fabricator will not want to make any changes to an existing counter top that they did not fabricate themselves. Fabricators will often not want to work on another fabricator's work. However, we have seen more success when a fabricator is going to increase the size of the cut out to fit the new sink. This option would be closer in relationship to getting a new counter top, but is extremely risky for the fabricator. Can the counter top cut in place, or will the top have to be removed? Who will remove it? What if the top breaks? What if the top was already cracked and no one was aware prior? 

 

Sink Size Has Entered the Chat... 

Sink size refers to:

  • Overall Front to Back of the Mounting Flange
  • Basin size front to back
  • Overall Left to Right of the Mounting Flange
  • Basin size Left to Right.

Note - The Sink and Cabinet Industry refer to overall sizing when describing a sink or cabinet. 

 Before I get too far ahead.. remember, you were trying to replace an existing sink, with an existing sink hole cutout. At this point, we are up to three variables of measurement; The Overall Sink Size, Sink Basin, and the Cut Out.   

    One important factor we have to mention, and I apologize to say,  just might sound insulting to some people, but, when we are trying to find a sink with all these elements mentioned here, we also have to take the measurements your are using. Using a tape measure is not simply reading numbers, but a practiced skill.

    • Are your measurements accurate? 
    • Is the tape measure accurate? (tape measures are not created equal)
    This might sound mundane, but think about how frustrating it could it be if you are an experienced "Measurer", but the tape measure itself is not manufactured well? After searching and comparing sinks and all the elements involved with fitment , it would be horrible to not have a correct fitment.

     

     Let's recap the obstacles we face trying to find a sink to replace an existing. 

    • The Various Sink Sizes
    • The Corner Radius
    • Existing Mounting Clips and Anchor Points

     The RARE EXCEPTION: Sometimes things can work out when replacing a sink, is when you are willing to change to a Drop-in sink.  Switching to a top mount or drop-in sink has it's own set of difficulty.  

    First - What we would look for is a top mount sink that has a bowl smaller compared to the existing hole, but the overall size is larger than the cut out

    "Oh that sounds easy!"  Sorry, No. It's not.

    Most sinks will have a front to back bowl size of 16".

    The counter top cut out could be 15 1/2" to 16 1/2".

    This means we have to find a sink with a bowl less than the above, with the mounting flange larger.  Keep in mind, as I stated above, most sinks have a bowl of 16".   Frustrating, right?   

    What about the holes that are cut out for the faucet or other parts? Will those be covered by the new sink's flange? Will they line up?  

    Unfortunately, the only professional and experienced advice we can give you is that you need to speak to a fabricator. Simply ask if they are willing to cut an existing top and install a new sink. To make this determination, the fabricator may need to come to the house to inspect the top. They may ask you a few questions, which you should be prepared to answer:

    1. What material is it? - Granite, Quartz? 

    2. What is the name of the Granite? Manufacturer and name of the Quartz?  Do you have a picture of it to send them? 

    3. Who did the counter top originally? How long ago? 

     

    If not, you might need a new counter top. I know, this is not what you wanted to read, but maybe reading all of this saved you a lot of time and frustration. If that's still a good thing, right? 

     

     

     

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