Gresham glass grows moss, algae and lichen on the pane, frame and seals, and Douglas fir and cedar drop pitch and needles on top of it all.
Gresham publishes no hardness figure, but mineral spotting is not the problem here; moss, algae and lichen on panes, frames and seals, and pitch and needles from fir and cedar, are. Everyone wants the same few dry weeks from June to September, so book early. Capacity rather than demand sets prices, and a single-story exterior runs $240 to $430.
Softness is the defining commercial fact of this market and it cuts against the trade: there is no mineral problem to solve, which means the deionised-rinse upsell has nothing to sell against and a plain tap rinse genuinely finishes the glass.
| Hardness | not published City of Gresham Public Works publishes no hardness figure in City of Gresham 2026 Drinking Water Quality Report (2025 data, PWS OR4100357). |
|---|---|
| Manganese | 0.0002–0.0438 mg/L |
| Sodium | 11–12 mg/L |
| Disinfectant | chloramine |
| Source and treatment | Portland's Bull Run supply until late fall 2025, then groundwater from the Cascade Groundwater Alliance well field in the Sand and Gravel Aquifer · Chlorine and ammonia disinfection, per the city's 2026 report; Portland's Bull Run water is not yet filtered, with a filtration plant due in 2027 · No softening step. |
Not in the report: pH, alkalinity, corrosion index, iron, chloride and total dissolved solids.
SOURCE · City of Gresham 2026 Drinking Water Quality Report (2025 data), PWS OR4100357 · How we source these numbers
Interval is set by biology and by conifers rather than by any mineral cycle, which is why a north elevation regrows visible film through the wet months no matter how well the last wash went.
OREGON SEASON BY SEASON →Gresham has essentially no mineral problem — tap rinsing gets spot-free glass, and the deionised upsell has nothing to sell against. Everything that makes work here is biological or resinous: moss and lichen growing into frame channels through the wet season, conifer pitch that water will not dissolve at any hardness, and gorge-outflow ice events that damage hardware rather than glass.
Gresham blends its own groundwater with Bull Run surface water bought from Portland, and Bull Run is among the softest municipal water in the country. The result is soft enough that mineral spotting is effectively a non-issue — a crew can rinse from the tap and get spot-free glass, which is rare enough to be worth saying out loud in a quote. Portland publishes Bull Run at 7 to 11 parts per million, around half a grain per gallon, which makes the purchased half of the blend among the softest municipal water in the country; the city wells are the unmeasured half here.
Because mineral is not the problem, the money in this market is in biology. Pacific Northwest damp grows moss, algae and lichen directly on glass and into frame channels and glazing seals, and on shaded north elevations it establishes within a single wet season. That is a scrub-and-biocide job, not a squeegee job.
Douglas fir and western red cedar drop needles, pitch and sap across most of the city. Conifer pitch is resinous rather than mineral — it does not dissolve in water at any hardness, and trying to squeegee through it just smears it across the pane.
The exterior season is compressed from the wet end rather than the cold end. With rain through most of October to May, the workable dry window is genuinely narrow, and demand stacks into it hard. Capacity, not demand, limits revenue here.
Columbia Gorge outflow gives east Multnomah County a weather pattern the rest of the Portland metro does not share. Cold air draining out of the gorge turns rain to freezing rain over Gresham and Troutdale while Portland stays wet, and those ice events damage frames, seals and hardware rather than just glass.
Portland-metro commercial overflows east along the I-84 corridor, which gives Gresham a commercial book out of proportion to its own downtown. That corridor work is standard modern storefront and is where route economics actually work.
Capacity rather than demand sets the number here, because the workable dry window is narrow and every customer wants the same few weeks. Against that, the I-84 corridor carries a commercial book out of proportion to the size of downtown, and that standard modern storefront work is where route density actually pays.
Tap water finishes glass here, so the technical barrier that stops homeowners in hard-water markets simply is not present in Gresham. What replaces it is moss and lichen rooted into frame channels and glazing seals, where the damage from scraping is permanent and the removal is a chemistry problem, and conifer pitch, which smears rather than dissolves and ruins a pass for anyone who meets it with a squeegee.
OPEN COST ESTIMATOR →2025 annual mean at the Portland - Humboldt School (PHS) monitor, 4915 N Gantenbein Avenue, 18.9 km west of the city (EPA site 41-051-2010).
2025 annual mean at the Portland - SE Lafayette St (SEL) monitor, 5824 SE Lafayette Street, 12.6 km west of the city (EPA site 41-051-0080).
Largest air release: Onsemi, 23400 NE Glisan ST (computers and electronic products), inside the city limits, 73,404 lb in 2024.
No one but authorized city staff may operate, connect to or otherwise interfere with a Gresham fire hydrant without the utility manager's written approval; approved users work under a hydrant use permit with a metering device, pay for the water and any damage, and lose the permit if they break its terms or an emergency arises.
Gresham Revised Code 5.30.010 and 5.30.020: fire hydrant use and use permit · checked September 2026
Gresham prohibits starting or continuing any non-stormwater discharge to its public storm system. The short list of allowed flows includes individual residential car washing, and it counts street wash water only when it comes from the city's own street cleaning, so a contractor's rinse off a building or sidewalk has to be kept out of the inlets.
Gresham Revised Code 3.23.010: discharge of pollutants · checked September 2026
Gresham has no historic district but keeps a landmarks list in its development code; any work that would change the exterior appearance of a Class 1 landmark goes to the Historic Resources Subcommittee and a hearings officer, and replaced features are expected to match the old in design, color and texture, so window swaps on those buildings need approval.
Gresham Community Development Code Section 5.0300, including 5.0313 and 5.0333: Historic and Cultural Landmarks Overlay · checked September 2026
The defining west-side Oregon substrate problem. North-facing windows under heavy canopy build a green-black film of mixed photosynthetic organisms that needs different chemistry than a normal wash. Sodium percarbonate or a quaternary ammonium prerinse, dwell five to ten minutes, then squeegee. Bleach is the wrong tool — it strips, but it lifts paint and stresses gasket rubber.
Anywhere with mature conifer canopy. The needle drop is mechanical and easy. The sap is a solvent-ladder problem — start with citrus, escalate only if needed.
Softness is the defining commercial fact of this market and it cuts against the trade: there is no mineral problem to solve, which means the deionised-rinse upsell has nothing to sell against and a plain tap rinse genuinely finishes the glass.
Residential window cleaning in Gresham typically runs $8–13 per pane or $240–430 for a standard single-story exterior. Capacity rather than demand sets the number here, because the workable dry window is narrow and every customer wants the same few weeks.
Gresham's drier, frost-free months are June to September, by NOAA's 1991–2020 normals for the Portland Troutdale Airport station, where November brings the most rain. The calendar on this page marks June (after the April 5 bloom and after smoke season and before frost). Frost nights usually run from November 20 to March 16.
City of Gresham Public Works publishes neither hardness nor dissolved solids, so rinse one pane and let it dry in sun; a white ring means switch to pure water. Iron, manganese, sodium and chloride all sit under this site's flags (highest: manganese up to 0.0438 mg/L). It draws on Portland's Bull Run supply until late fall 2025, then groundwater.
In Gresham the dominant residue patterns include moss, algae and lichen on glass, frames and seals and douglas fir and cedar pitch and needle drop. Interval is set by biology and by conifers rather than by any mineral cycle, which is why a north elevation regrows visible film through the wet months no matter how well the last wash went.
Tap water finishes glass here, so the technical barrier that stops homeowners in hard-water markets simply is not present in Gresham.
Restored historic main street with storefront transoms and upper-storey sash. Compact, walkable, and consolidates well into a single commercial stop. Rockwood and Powell Valley have their own housing stock and glazing as well.
Just over the Oregon line