Once your shelf is reinstalled, do not overload it. No DIY fix will be as perfect as a new replacement, so think about how you distribute weight throughout your refrigerator, especially when the ...

Use a plastic wrap with a sealant on it and lay the wrap across your shelves. If the shelves get coated in food or an exploded drink, you simply remove the wrap. No real cleaning is required.

Depending on the type of legs that your add-on shelf have, it might fall through the built-in shelves in your refrigerator, so be aware of this when searching around for a wire rack to use.