Outside of where I'm currently residing is a brick patio. When I first arrived, it was brought to my attention that an area of the bricks has been staying moist (please see attached photos). It's not from rain coming down. My thought is that it may be seeping up through the bricks. There is a rain irrigation system that runs underneath. I was thinking that perhaps it was leaking from the PVC pipes. Any ideas on what it could be? Thanks. I'm just thinking, maybe something spilled here... maybe a stain. Maybe some TSP or muriatic acid and a wire brush.?
Michael
Michael