Mineral Deposits and Rain Spots on Windows
Mineral deposits are the white or cloudy spots left when hard water or rain dries on glass. Light spotting can come off during a normal pure-water exterior clean, while heavy or long-untouched deposits need a specialty treatment that is quoted separately from the flat rate.
Describe the job and add your city. Free to request, no obligation.
Storms bring rain spots, grit and a film of pollen or dust, and a sprinkler aimed at the glass leaves minerals every time it dries. Fresh spotting is far easier to lift than deposits that have baked on through a few summers. The longer a deposit sits, the more likely it is to need that separate treatment.
Describe what you see when you ask for help, including how many windows are affected and how long the marks have been there. Exterior work is seasonal in Greater Montréal, about March to November, so plan stain work for the warm months.
What the work includes
- Light rain spotting and pollen film cleared during a normal pure-water exterior clean
- Exterior glass, frames and sills cleaned with pure deionized water on a water-fed pole
- Screens rinsed in place
- A specialty treatment for heavy or long-untouched mineral deposits, quoted separately
- A quote for the specialty work that stays separate from the flat exterior rate
- Streak-free guarantee on the clean: report a streak within 24 hours and the crew returns free
Signs of mineral deposits rather than plain dirt
White or cloudy spots that stay after you wipe the glass
Rings or a stripe pattern where a sprinkler hits the window
A rough, chalky feel when you run a fingertip over the glass
Spotting that returns within days of a normal wash
Marks concentrated at the bottom of the glass and on the sills
A hazy look that is worst when the sun hits the glass
How the work goes, step by step
Describe the marks
Tell us how many windows are affected, where they face and how long the spotting has been there.
Get the treatment quoted
Heavy deposits are quoted separately from the flat rate, so you see that cost before agreeing to it.
Exterior clean
Glass, frames and sills are cleaned with pure water on the water-fed pole, and screens are rinsed in place.
Specialty treatment, if quoted
Windows with heavy deposits get the separately quoted treatment.
Report any streak
If a streak appears after the visit, tell us within 24 hours and the crew returns free.
What changes the price
- Age of the deposits
- Fresh spotting is usually handled in a normal clean. Deposits left for years are the ones that need a specialty treatment and a separate quote.
- Number of windows affected
- A few windows by one sprinkler are a smaller job than a whole side of the house marked by hard water.
- Where the water lands
- Sprinkler overspray hits the same windows repeatedly, which builds heavier deposits than occasional rain does.
- Height and access
- The pole reaches up to three storeys from the ground. Taller or hard-to-reach windows can need a site visit before a price is set.
- Regular cleaning on the same visit
- The exterior flat rate by window count applies to the regular clean, and the deposit treatment is quoted on top.
What a good quote spells out
- Which windows are treated for deposits and which only get the regular exterior clean
- What the specialty treatment costs, written separately from the flat rate
- What result to expect, since deposits that have etched into glass may not come out completely
- Whether the sprinkler or another source of hard water will keep marking the glass
- The streak guarantee terms: report within 24 hours and the crew returns free
Post-Storm Deposit Removal: questions people ask
What causes mineral spots on windows?
Hard water or rain dries on the glass and leaves behind the minerals it carried. Sprinklers aimed at windows are a common cause, and repeated drying builds the spots into a harder deposit.
Will a normal window cleaning remove mineral stains?
Light mineral spotting usually comes off during a normal pure-water clean. Heavy or long-untouched deposits need a specialty treatment, which is quoted separately.
How can mineral spots be kept from coming back?
Redirect sprinklers away from the glass and keep the windows on a regular cleaning schedule. Regular visits keep deposits from building up.
Is stain removal part of the flat rate?
No. The flat rate covers the exterior clean of glass, frames and sills. Heavy mineral stain removal is quoted separately.
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