Material by Material
Natural cleft bluestone is everywhere in Newtown Square, Gladwyne and Haverford. The face is layered by nature, and a zero-degree tip held close will lift those layers. Once a slab flakes, it stays flaked. Concrete pavers are very tolerant of pressure but joint sand comes out with the moss and has to be replaced — any paver quote that does not include re-sanding is quoting an incomplete job. Stamped and colored concrete in 2000s Paoli and Blue Bell has color and sealer that are surface-thin — aggressive cleaning takes both off and leaves a patchy result that only re-sealing fixes.
What Is Actually Staining It
Green and black film is algae and mildew driven by shade — a cleaning solution kills it, pressure alone removes only the top layer. Leaf tannin is the brown shadow left under where leaves sat all winter, heavy in Wynnewood and Haverford — it is a chemistry job, not a pressure job. Efflorescence is white powdery bloom pushed out from inside the masonry and needs a dedicated treatment. Rust from fertilizer granules or metal furniture needs a rust-specific product. Grill grease and oil need degreaser with dwell first, then pressure.
Order of Work on a Full Property
Hardscape goes last. Runoff from roof cleaning, gutter cleaning and house washing all lands on the patio and walks, so cleaning them first means cleaning them twice. Re-sanding paver joints is the final step, after everything above is done.
See also: House Washing Main Line PA · Pool Deck Cleaning Main Line PA
By Town
Newtown Square (19073): the most hardscape per property in our area — large bluestone terraces, long walks, extensive patio-to-pool deck transitions. Gladwyne (19035): wooded acre-plus lots with sloping stone paths and heavy moss pressure. Haverford (19041): estate courtyards, original stone steps, specimen-tree shade and tannin staining. Blue Bell (19422): open full-sun lots, the longest intervals, mostly modern pavers and stamped concrete. Wynnewood (19096): street trees over front walks so tannin and film return on a predictable annual cycle. Conshohocken (19428): steep steps and hillside walks, the highest de-icer exposure. Ardmore (19003): narrow side walks between twins, tight access. Narberth (19072): small borough lots, short runs, older brick walks. Paoli (19301): 1890s brick alongside 2000s stamped concrete, sometimes on the same property. Malvern (19355): historic borough brick and large modern township patios.