Undermount Sinks Problems in Granite and Quartz
One of the many advantages of granite and quartz countertops in a kitchen is the unique option to “undermount” a stainless, composite, or cast-iron sink.
Not only do they look great, they are supremely functional because the stuff destined for the garbage disposal can be easily wiped into the bowl without the annoying flange that is common with a top mounted sink!
But beware, improper installation techniques and sub-standard sealants can turn your dream counters into a nightmare of repair costs and inconvenience.
Here are the top 3 problems with undermount sinks (and how to avoid them):
1. Sink Delamination and Failure: When a granite and quartz installer fails to use a mechanical sink attachment like clips, rails, or brackets to secure the sink to the countertop, silicone adhesive is generally the method.
Unfortunately, the weight, moisture, and vibration of the garbage disposal will literally pull the sink away causing it to separate and fail.
The result is moisture problems in your sink cabinet, stressful haggling with the installer to fix it, and even costly repair bills to make it right!
2. Permanent Installation and Sink Damage: To limit the number of sink failures due to the limitations of silicone, sinks are sometimes installed with a permanent epoxy or a plywood substrate.
The problem with this technique is that if the sink is defective or damaged, there is no way to remove and replace it without destroying the granite or quartz counter top or cabinetry!
3. Moldy or Cracked Caulk: Just like topmount sinks, undermount sinks on granite and quartz need to be sealed to prevent moisture from creating mold and mildew problems in the cabinet. Improper sealants like silicone or painters caulk (yes painters caulk) and hasty application of the correct sealants are the most common culprits.
These problems are only problems for consumers who aren’t aware of them.
So don’t let them scare you away from the beauty and benefit that an undermount sink provides!
Just make sure you understand them well enough to ask the granite and quartz installer how they plan to deal with them on your project!