Can I use this rubber outside for a swing set?

You can use our 3/8" Heavy Duty Rubber Rolls outdoors under a swing set. The rolls will help to protect the ground under the swing set from being destroyed. Our rubber flooring is very slip-resistant and is more so when wet. Our rubber rolls are also mold and mildew resistant. The only thing you will notice while having this rubber roll outdoors is that it will fade a bit in direct sunlight.