Other areas of mold growth are kitchen faucets and the seam between the countertop and the back wall. This could be grouted tile, a stone 4-inch backsplash, or in some cases, drywall only. The amount of water transported to this seam area from washing dishes / pots by hand is tremendous. Additionally, the water on our hands when working in the kitchen is constantly landing against this seam. Side note (kids may or may not be careful with water all the time!) At least my 4 kids. 

If the caulking is not sufficient, water needs only the smallest of cracks to work its way down behind the countertop and into the drywall, cabinet, or both. This is an area that would then have the necessary warmth, moisture content and ample organic material in the form of drywall paper and wood to grow mold. 

If there is a lot of moisture in these areas, it will eventually work its way down to the finished flooring, then to the subfloor lumber and potentially into the wall and floor framing materials. This is one of the most-expensive mold remediation projects due to all the components that must be removed, remediated, then rebuilt. 

All the plumbing pipes under the kitchen sink also carry potential risk. The drains are usually made of plastic, there are hot and cold water supply lines, plus a dishwasher supply line. Add to this all the various items we store under the sink, such as cleaning products, paper and plastic bags, sponges, etc. People tend to store more items under the sink over time and aren’t aware of what’s happening with the water pipes or with the back of the cabinet. 

Kitchen appliances

There are several areas to keep an eye on in the appliance category. Refrigerators with a water supply and ice maker are high on the list. The parts under a refrigerator can fail for various reasons and often leak slowly. The same is true for the dishwasher, except the dishwasher has water supply from under the sink, which has connections you should keep an eye on. Plus, there is a discharge hose back to the sink cabinet with two more connections. All of these are made of plastic, with the exception of the supply line from the water line which is typically a steel braided line. Over time, plastic components can become brittle and form small cracks so keep them in mind. 

Maintenance 

In general, the only possible way to stop these areas from becoming potential mold growth hazards is to keep an eye on them, and then performing proper maintenance. Caulking once a year, water moisture alarms, and managing the number of items under the sink are all important. 

In addition, I recommend having a backsplash of some kind behind every faucet, rather than drywall alone.