Exterior Cleaning Glossary: Iowa Homeowner’s Reference

Plain-English definitions of every term you’ll hear from window cleaning and pressure washing companies in the Des Moines metro. Use this glossary to decode quotes, compare bids, and know exactly what you’re paying for, from Ankeny to Waukee.

Soft washing

Soft washing is a low-pressure cleaning method (under 500 PSI) that uses biodegradable detergents to kill mold, algae, and bacteria on siding and roofs instead of blasting them off. It’s the right choice for Iowa vinyl siding, which turns brittle after years of freeze-thaw cycles and cracks under high pressure. Most professional house washing in Des Moines is actually soft washing, and the results last longer because the organic growth dies at the root.

Pressure washing vs power washing

Pressure washing is cleaning with high-pressure cold water, while power washing adds heated water to the same process. The heat helps dissolve grease, gum, and the road salt residue that Des Moines metro driveways collect every winter from Iowa DOT brine treatments. For most flatwork, professional pressure washing with the right detergents gets equal results, so don’t pay a premium for “power washing” unless there’s oil or grease involved.

PSI

PSI (pounds per square inch) is the measurement of how much force a pressure washer’s water stream delivers. Concrete can handle 3,000+ PSI, but vinyl siding, window seals, and roof shingles need under 500. Central Iowa concrete is especially vulnerable to over-pressuring because decades of freeze-thaw cycles leave micro-cracks in the surface; too much PSI etches permanent wand lines into a driveway that no amount of rinsing removes.

GPM

GPM (gallons per minute) is the measure of water flow a machine produces, and it matters more than PSI for most cleaning jobs. Higher flow rinses debris away faster, which is why pros run 4 to 8 GPM machines. In mature-tree neighborhoods like Beaverdale or older Urbandale, spring oak pollen coats entire driveways, and it’s flow, not force, that carries all that yellow film off your concrete.

Surface cleaner

A surface cleaner is a round, hooded attachment with spinning spray bars that cleans flat concrete in wide, even passes. It eliminates the zebra striping you get from cleaning a driveway with a wand alone. On big Iowa driveways and three-car garage aprons common in Waukee and Grimes subdivisions, a surface cleaner cuts cleaning time in half and leaves a uniform finish that wand work can’t match.

Water-fed pole

A water-fed pole is a telescoping pole with a soft brush that delivers purified water to clean windows up to four stories high from the ground. It removes the ladder risk on steep-lot homes common around Des Moines’ rolling terrain. Professional window cleaning companies in Des Moines use water-fed poles for exterior glass because the purified water dries spot-free without squeegeeing, even on second-story windows above landscaping.

Deionized (DI) water

Deionized water is water that’s been filtered to remove all dissolved minerals, so it dries on glass without leaving spots. It’s essential in central Iowa, where municipal water runs hard and private well water in rural Dallas and Madison County runs even harder. Regular hose water here can carry 20+ grains of hardness, which is exactly why rinsing your own windows with a garden hose leaves them looking worse than before.

Squeegee technique

Squeegee technique is the traditional method of cleaning glass with a mop and rubber-bladed squeegee, still the standard for interior windows and detail work. A skilled tech leaves zero streaks and wipes edges dry with a lint-free towel. It matters most on interior glass in winter, when Iowa’s furnace-dried indoor air makes cleaning solution flash-dry fast and sloppy technique shows up as haze the moment the sun hits the pane.

Hard water stains (mineral etching)

Hard water stains are white, cloudy mineral deposits left when water evaporates on glass, and over time the minerals chemically bond to and etch the surface. The classic central Iowa cause is sprinkler overspray hitting first-floor windows all summer in Waukee, Ankeny, and Johnston subdivisions. Fresh spots wipe off; stains older than a season usually need professional hard water stain removal with polishing compounds before the glass is permanently damaged.

Oxidation (chalky siding)

Oxidation is the chalky white film that forms on vinyl and aluminum siding as UV rays break down the surface over years of sun exposure. Wipe your siding with a dark rag; if it comes back powdery, that’s oxidation. Iowa’s strong summer sun hits south- and west-facing walls hardest. Oxidized siding needs careful low-pressure washing, because sloppy wand work leaves permanent shiny streaks in the chalky layer.

Gloeocapsa magma (black roof streaks)

Gloeocapsa magma is the airborne cyanobacteria responsible for the black streaks running down asphalt shingle roofs across Iowa. It feeds on the limestone filler in shingles and spreads fastest on humid north-facing slopes. Des Moines’ muggy summers make it nearly universal on roofs older than ten years. Professional roof washing kills it with a soft wash treatment; pressure washing a shingle roof voids most manufacturer warranties.

Artillery fungus

Artillery fungus is a wood-decay fungus that grows in hardwood mulch and shoots sticky black spores up to 20 feet onto siding, windows, and cars. The tar-like specks bond so tightly that even professional washing often can’t remove every one. It thrives in the damp, shaded mulch beds along north-facing foundations in Iowa springs. Switching to cedar mulch or rock beds near the house is the only reliable prevention.

Efflorescence

Efflorescence is the white, powdery mineral deposit that appears on brick, concrete, and stone when water moves through the masonry and evaporates, leaving salts behind. Iowa’s freeze-thaw cycles drive moisture deep into retaining walls and foundation brick, so efflorescence is common on Des Moines area homes every spring. It brushes or washes off, but if it keeps returning, that’s a sign of a moisture problem worth investigating, not just a cleaning issue.

Ice dam

An ice dam is a ridge of ice that forms at the roof edge when attic heat melts snow that refreezes over the cold eaves, backing meltwater up under the shingles. Central Iowa’s January freeze-thaw swings make ice dams a yearly threat, and gutters packed with fall leaves make them worse by trapping the first refreeze. Late-fall gutter cleaning is the cheapest ice dam prevention there is.

Downspout flush

A downspout flush is running water through each downspout after gutter cleaning to confirm it drains freely from top to outlet. It’s the step that separates thorough gutter work from a quick scoop-and-go, because clogs love to hide in the elbow joints. Iowa’s heavy maple and oak seed drop in spring packs downspouts with helicopters that a visual check from the ladder simply can’t see.

Gutter guards

Gutter guards are screens, foam inserts, or micro-mesh covers installed over gutters to keep leaves and debris out while letting water in. They reduce cleanings but don’t eliminate them; shingle grit, pollen, and maple seeds still build up on top of and inside most systems. In heavily treed Des Moines neighborhoods, guarded gutters still benefit from an annual inspection, and cheap foam inserts often make Iowa ice damming worse.

Sodium hypochlorite (SH) mix

Sodium hypochlorite is the active sanitizing ingredient in soft wash solutions, essentially a professional-strength version of household bleach diluted to the job. A typical house wash runs 1 to 3 percent SH; roofs need stronger mixes to kill Gloeocapsa magma. A responsible Iowa contractor tells you their mix ratios, pre-wets your landscaping, and rinses plants after treatment, because hostas and hydrangeas common in Des Moines beds are sensitive to overspray.

Pre-wet / rinse

Pre-wetting is soaking landscaping, grass, and adjacent surfaces with plain water before applying cleaning solutions, and rinsing is doing it again afterward. Saturated plants absorb less detergent, so overspray does no harm. This matters in established Iowa yards where mature perennial beds sit tight against the foundation. If a house washing crew starts spraying detergent without wetting your plants first, that’s a red flag worth stopping the job over.

Screens & tracks

Screen and track cleaning is the removal, washing, and reinstallation of window screens plus vacuuming and wiping the channels your windows slide in. Iowa screens trap a full season of oak pollen, cottonwood fluff, and dust from spring field work blowing in from farmland surrounding the metro. Dirty screens re-contaminate freshly cleaned glass with the first rain, which is why thorough screen cleaning is bundled into a proper window cleaning visit.

Storm windows

Storm windows are secondary panes mounted outside or inside primary windows to add insulation, common on older Des Moines homes in Sherman Hill, Beaverdale, and the Drake neighborhood. Cleaning them properly means removing each storm panel, cleaning four glass surfaces instead of two, and reinstalling without bending the frames. Expect quotes for storm-window homes to run higher; anyone quoting the same price as modern double-hungs probably isn’t planning to remove them.

Low-E glass

Low-E glass is window glass with a microscopically thin metallic coating that reflects heat, keeping Iowa homes warmer through subzero Januaries and cooler through humid Augusts. On most modern windows the coating sits inside the sealed unit, safe from cleaning. But some units carry exterior-surface coatings that abrasive pads or razor scraping can permanently scar, which is why a pro asks about your window manufacturer before attacking construction debris or paint specks.

Wood brightener

Wood brightener is an oxalic or citric acid solution applied after washing a deck to neutralize cleaners, open the wood grain, and restore the natural color of gray, weathered boards. Iowa cedar and pressure-treated decks gray fast under the combination of intense summer UV and winter snow load sitting on the boards. Professional deck washing that includes a brightening step leaves lumber looking years newer and ready to accept stain evenly.

Sealing (concrete and glass)

Sealing is applying a protective coating after cleaning: penetrating siloxane sealers for concrete, hydrophobic polymer coatings for glass. For Iowa driveways, sealing is arguably more valuable than the cleaning itself, because it blocks the water intrusion that freeze-thaw cycles and road salt turn into spalling and pitting. Sealed glass sheds rain and sprinkler water instead of letting minerals bake on, stretching the time between window cleanings.

Solar panel soiling

Solar panel soiling is the buildup of dust, pollen, and bird droppings on panels that blocks sunlight and cuts energy production, often by 5 to 20 percent. Central Iowa panels collect field dust from spring planting and fall harvest, plus a heavy oak pollen coat every May. Rain alone doesn’t remove the bonded film. Professional solar panel cleaning uses purified water and soft brushes so warranties stay intact.

Curb appeal package

A curb appeal package is a bundled service, typically house washing, window cleaning, and driveway or walkway cleaning done in one visit at a discount over booking each separately. It’s the standard prep for listing a home, and Des Moines realtors often schedule one before photos because a clean exterior photographs dramatically better. Bundling also makes sense practically: washing the house after cleaning the windows would just dirty the glass again.

Service plan

A service plan is a recurring maintenance schedule, usually two to four visits per year, that keeps windows, gutters, and siding clean automatically at a lower per-visit rate. In Iowa the rhythm practically writes itself: spring cleaning after oak pollen drops, a summer touch-up, and late-fall gutter clearing before the first hard freeze. Plans also mean priority scheduling during the October rush, when every gutter in the metro fills at once.

Hear a term we didn’t cover?

Hear a term we didn’t cover? Text us at (515) 642-1986 and we’ll give you a straight answer, no sales pitch. We’re a local Des Moines metro crew, and we’d rather you understand exactly what you’re buying before anyone puts a ladder against your house.

Last updated: August 2026