Did you know that mucking one stall once per day taking 15 minutes to do, you’ll spend 91 hours and 15 minutes per year per horse doing so? Did you also know that in high school I had a weekend job at a training and boarding barn and would clean up to 25 stalls per day? Add those hours to the time spent cleaning my own horses stalls and I’ve had a lot of time in contact with shhhhovels… and pitchforks.
So I can tell you the flooring of a stall can be the bane or the relief of your stall cleaning burdens. A properly installed stall floor eases maintenance, protects your horses well being and comfort, and will save you on bedding waste and therefore cost.
An ideal stall floor looks something like this:

In my experience that drainage layer is really important with soil or clay based floors. Without it, water or urine will eventually seep through any seams or edges of the mats and that soil will get wet and over time the mats will start to sink and become uneven. Then one day when your stall floors look more like ski moguls you’ll have to remove all the mats and fix the base and it will be a pain and then you will curse the day you decided to get horses and question your mental status. But, as a horse owner that happens about twice annually anyway… it will pass don’t worry.
So, we started with a leveled out dirt surface in the stalls, tamped that down well. Then had gravel delivered (we had it spread over the whole barn floor as well) and we leveled that and tamped it down too. Then covered the gravel layer with 4 x 6 rubber stall mats from tsc. We had to cut them with a jigsaw to make them fit edge to edge.


They took some time to install, and you for sure need at least 2 people to move these heavy awkward things around. But they are working great, are comfortable and make stall cleaning a snap.
There are mat options out there that could be custom sized to fit your space without any seams, and some that are very cushioned but are much more costly. If your horses are stabled a great deal or you are running a business of boarding etc that may be worth considering though.

But for most backyard horseman this method is fairly simple, not too costly, and eases that daily workload.