A screened pool enclosure traps humidity, which is exactly what mildew wants, so lanai decks tend to go green faster than anything else on the property. We clean textured cool decking, pavers and travertine at pressures the surface can actually take, and we are careful around screens, cages and pool equipment. Pool decks run $125 to $250 depending on square footage and how long it has been. Most people have this done alongside the patio, or as part of the complete exterior package.
