Microfiber mops work so well that they become saturated with dirt very quickly. Where you might be used to using one conventional mop for an area that’s 2000 square feet or so, you might find that you need to use 4 or more microfiber mops to mop the same area.
Once you start using your microfiber wet mops inevitably you’re going to wonder at what point should you switch out the mop for a clean one. With the exception of mopping hospital patient rooms where guidelines dictate that you use one per room to prevent cross contamination, there is no definitive answer to this question. This is because there are so many factors involved; how big is the mop, how dirty is the floor, how often is it mopped, etc. Do you use the same mop for the entire job? Usually not. Should you rinse out and reuse the same mop? No, there really isn’t a reason to since they’re so inexpensive; you should have enough mops to complete the job and rinsing isn’t really going to get all of the dirt out of the mop.
With experience you’ll get a good idea of idea of when a microfiber mop will become saturated. Assuming you’re starting with a damp (not dripping mop), a good rule of thumb is to change out the mop once it starts drying out, by then it’s probably picked up as much as it’s going to pick up. Also, once a microfiber wet mop has dried out it becomes much less effective.
At my house I mop the floor usually about once a week. Downstairs is about 1500 square feet of hardwood and tile. When I mop the floor I usually use two or three 18” microfiber dust mop pads and then four 18” microfiber wet mop pads. That means I’m covering about 500 square feet with the dust mop pads and about 400 square feet with the wet mop pads. The image above is a microfiber wet mop after I used it to mop my family room. You can see how soiled the mop is after cleaning about 400 square feet. (By the way, I’ve been using that mop for about 5 years and it gets washed probably every other week, so that mop has been washed about 125 times.) Even though I mop about every week our floors get really dirty between moppings… we have a huge dog with feet the size of frying pans who doesn’t wipe them when he comes in, we wear our shoes in the house and we’re constantly in and out tracking whatever attaches to our shoes into the house.