I used AQUA-REPEL on 12-year-old concrete patio slabs that had been pressure washed several times to remove dirt, algae and lichen. The surface itself was beginning to deteriorate so decided to put a sealant on them and I had used this product 18 months ago.
I found it easy to apply, no mess, and, once dry, is undetectable (surface looks fully dry – no sign of wet look). When it rains, the patio continues looks dry with water forming droplets on the surface and running off.
I’ve had no algae forming on the slabs since applying AQUA-REPEL and I’ve pressure washed the patio to remove dirt and mud from the garden a couple of times without noticeably changing the water repellency, although I didn’t go mad with the pressure washer.
I’ve just purchased some more for the paths around the house.