Cleaning the windows you can reach from the ground is a fine weekend job. The upper floor is a different task, and not because the glass is any dirtier. Two things change once a window is ten or fifteen feet up: the job gets genuinely dangerous, and getting a streak-free result gets genuinely hard. In Houston, both problems are a little worse than average. Here is why I tell homeowners to let a pro handle the high glass.
The safety case is stronger than it looks
A ladder feels routine, which is exactly the problem. The data that exists on ladder falls is occupational, meaning it covers workers who use ladders for a living, and even they get hurt at rates worth respecting. The people most practiced at ladders still land in the emergency room, most often from the exact height of a second-story window.
According to CDC and NIOSH data on occupational ladder falls, fall heights of six to ten feet were the most common, accounting for half of the emergency-department-treated cases, and nearly 90 percent were from under 16 feet (CDC / NIOSH). A typical second-floor sill sits right in that band. These falls are also more serious than an average injury: the same data shows the hospital admission rate for ladder-fall injuries was about 14 percent, close to three times the overall rate.
What causes them is telling. NIOSH reports that roughly 40 percent of ladder-related injuries come from the ladder sliding out at the base because it was set at the wrong angle, and it names overreaching while on the ladder as another top cause (CDC / NIOSH). Reaching sideways to wipe the far corner of a pane is precisely the move that gets people hurt. OSHA’s basic rules make the point: keep three points of contact, set the base a quarter of the working length out from the wall, use the ladder only on stable and level ground, and never stand on the top three rungs (OSHA). Those are the first rules to go when a homeowner is stretching for one more window over a flowerbed on uneven Houston ground.
The quality case is a Houston water problem
Even if you clean the high glass safely, there is a second reason the result often disappoints: our water. Houston’s tap water is officially hard. The U.S. Geological Survey classifies water from 121 to 180 milligrams per liter of calcium carbonate as hard (USGS), and Houston Public Works’ own water quality reporting puts the main system’s total hardness at an average around 136 parts per million, with peaks well into the very hard range (Houston Public Works). Those dissolved minerals are what dry into the chalky spots you see after the water evaporates.
This is where the pros have a real technical edge, not just a marketing one. The National Glass Association’s cleaning guidance says pure-water pole systems need water with a total dissolved solids content of 20 parts per million or less to prevent spotting and streaking, and states plainly that tap water is not acceptable for it (National Glass Association). Houston tap water sits far above that, so a garden hose and a squeegee are fighting the water itself. Professionals run their water through de-ionizing or reverse-osmosis filters first, which is why their windows dry clear and a DIY rinse dries spotted.
Technique matters too, and it is harder on unreachable glass. The same guidance says to work top down, to avoid cleaning glass in direct sunlight, and never to let cleaning residue dry on the surface, all of which cause spotting. On a hot Houston afternoon, water flashes off an upper south-facing pane before you can squeegee it, and there is no easy way to work fast on glass you can barely touch.
How professionals solve both problems at once
The modern answer to high windows solves the safety problem and the water problem together: a water-fed extension pole. It reaches upper floors from the ground, which removes the ladder and the fall risk entirely, and it feeds purified, low-mineral water that rinses the glass without leaving spots. That combination is the whole reason the method exists.
A pro also identifies your glass before touching it. Coated and tempered glass can be permanently scratched or etched by the wrong tools, and the National Glass Association warns never to use a razor on coated glass. Knowing what you have, and cleaning screens and sills that trap Houston pollen and mineral dust, is the difference between clean windows and a callback.
When doing it yourself is fine
I am not saying never clean your own windows. Ground-floor glass you can reach with both feet planted is a perfectly good DIY job, and if you want the spotting to behave, dry the glass with a squeegee before the sun does and finish with a microfiber cloth. The line I draw is height. Once the window is up a story, the fall risk and the hard-water math both tip toward hiring it out.
If you would rather not chance the ladder, our window cleaning crews clean upper-floor glass from the ground with purified water, and we often pair it with a house wash so the whole exterior matches. It is safer, and honestly it looks better than a hose ever will.
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References
- CDC / NIOSH, Occupational Ladder Fall Injuries, United States, 2011 (MMWR), https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6316a2.htm
- CDC / NIOSH, Ladder Safety (Falls in the Workplace), https://www.cdc.gov/niosh/falls/ladder/index.html
- OSHA, Portable Ladder Safety QuickCard (3246), https://www.osha.gov/sites/default/files/publications/PORTABLE_LADDER_QC.pdf
- USGS, Water Hardness Information, https://www.usgs.gov/faqs/do-you-have-information-about-water-hardness-united-states
- Houston Public Works, Water Quality Report 2022, https://www.houstonpublicworks.org/sites/g/files/nwywnm456/files/doc/003-water-quality-report-2022.pdf
- National Glass Association, FB01-00 Proper Procedures for Cleaning Architectural Glass, https://www.glass.org/sites/default/files/2023-12/FB01-00_2023_Proper_Procedures_Cleaning_Architectural_Glass_Products.pdf
