Algae and Black Mildew on Shaded Pinellas Pavers

A north-side walk, a screen-enclosure floor, and any patio under a dense oak will grow a black film in Pinellas. That is algae and mildew sitting on a damp face, not a failed paver. Pressure-washing it at full blast empties the joints and leaves a field that weeds in six weeks.

What actually works

• A cleaner matched to organic film, not a mystery acid that etches the face.

• Lower pressure and a fan tip so the sand stays in the joint.

• A dry day to re-sand, then a light water-in so the polymer can set.

• A look at irrigation overspray and downspouts — the film comes back if the surface never dries.

When cleaning is not enough

If the field has already settled into a dish that holds water, the film will return no matter how pretty the first Saturday looks. We re-level the low area, restore pitch, and then clean. Shade is a given on many Pinellas lots. Standing water is not.

Call 727-490-9798 if the walk is slick or the lanai floor looks stained instead of just dirty.