On 2/19/2017 12:39 PM, home owner wrote:
Envirotile„¢ rubber pavers

From their website: http://www.envirotile.ca/faq.html
The white spots you see on your tiles are referred to as efflorescence.
Efflorescence is caused when soluble salts and other water materials
come to the surface of concrete and mortars. In this case, because the
tile is porous, it rises to the surface of envirotile„¢. Efflorescence
will dissolve in water, so pressure washing or wet scrubbing with a soft
brush and mild detergent will remove the stain and it will wash away.
You must be careful to rinse the surface with fresh water so that no
residue is left to dry on the tile.

Interesting product. I see warranty is 5 years. They say sunlight does
not affect but usually plastic products do age and oxidize. Tires can
dry rot and I might expect it here.