Clean Freaks Co. Screen cleaning and repair in Los Altos Hills.

On the Mid-Peninsula hillsides, a window screen is not a passive dust catcher — it is the first surface the oak canopy loads. Coast live oak and valley oak shed pollen in long spring flushes, drop tannin-heavy leaf litter into fall, and release a fine catkin debris that the marine layer presses flat against mesh. Where the fog sits longest — north and west elevations, and windows tucked under deep eaves — that debris does not blow off. It stays damp, oxidizes, and bonds into the weave as a grey film that reads as a permanently dim window from inside.

The materials on these homes complicate a simple hose-down. Fiberglass mesh flexes and belllies if scrubbed dry; aluminum mesh pits and chalks where fog moisture lingers against an oxidizing frame; and the spline that holds either into its channel goes brittle after a few Peninsula winters of wet-then-dry cycling. A screen that looks merely dirty is often also loose, stretched, or torn at a corner — and forcing a cleaning motion across it finishes the tear.

Then there is the frame inventory. Older hillside houses mix hardwood casement screens, extruded aluminum sliders, and retractable door screens on a single elevation, each demanding its own removal sequence, its own drying orientation, and its own decision about whether to clean, re-spline, or re-mesh. That triage — not the washing — is the actual work, and it is why this is its own category rather than an add-on to a window wash.

1. The partner maps and tags every screen by elevation before removing one — noting the fog-shaded north and west runs that carry the heaviest oak film, so each screen returns to the exact opening it was fitted to rather than being shuffled between similar frames.
2. Mesh is cleared wet and supported, never scrubbed dry: fiberglass is soft-brushed flat on a padded surface to avoid bellying, and aluminum mesh is treated for the chalky oxidation that fog moisture leaves against the frame, then rinsed clear of tannin staining rather than driven deeper into the weave.
3. Every frame is checked for the brittle, sun-and-fog-cycled spline that fails on Peninsula homes — loose or split spline is replaced, torn corners on hardwood casements are re-meshed, and retractable door screens are cleared of grit in the track so they retract cleanly instead of binding.
4. Screens are dried in orientation before reinstallation so trapped fog moisture cannot wick back into a hardwood frame or sit in an aluminum channel, and each is reseated square so it seals against the opening instead of rattling in the hillside afternoon wind.

• Late spring, after the oak pollen flush — once valley oak and coast live oak finish shedding, the yellow-green film they leave on north-facing mesh is at its heaviest and worth clearing before summer entertaining.
• Early fall, ahead of the first wet fronts — clearing tannin-heavy leaf litter and re-splining brittle frames now means screens are seated and sealed before winter rain drives moisture into loose corners.
• After a long fog-shaded stretch — homes on north and west hillside elevations that sit under the marine layer for weeks develop a matted grey film that a routine window wash leaves untouched.
• Following fire-season debris or defensible-space clearing — dry-season ash and fine grit driven against screens, and the dust kicked up by hillside brush work, load mesh far faster than a level lot would.
• Before listing or a seasonal reopening of a second home — when interior light quality across every elevation needs to read clean and even, not dimmed by a canopy the mesh has been collecting for a season.