A pop-up waste is a type of sink drain that includes a mechanism that allows you to open and close the drain using a lever or button. The pop-up waste is typically used in conjunction with a sink that has an overflow, which is a small hole in the rim of the sink that allows water to drain out if the sink becomes too full.
Whether you need a pop-up waste with or without an overflow depends on the type of sink you have and your personal preference. If your sink has an overflow, you can choose a pop-up waste with an overflow, which will allow you to close the drain and prevent water from flowing out through the overflow. If your sink does not have an overflow, you can choose a pop-up waste without an overflow.
In general, it is a good idea to choose a pop-up waste with an overflow if your sink has one, as it can help to prevent water from spilling over the edge of the sink if it becomes too full. However, if you prefer the look of a sink without an overflow, you can choose a pop-up waste without an overflow and simply be mindful of the amount of water you use in the sink to avoid any spillage.