How soon before an event should windows be cleaned?

The date that matters is the one on the invitation. A pane cleaned on any earlier day looks its clearest on that earlier day, and every day after it is time for something new to settle.

The glass industry's own technical paper frames cleaning around what is on the glass rather than around a calendar. NGA's Glass Technical Paper FB01-00 says that for routine maintenance, glass should be thoroughly cleaned as dirt and residue appear, with frequencies tailored to the site and the local environment, and its do-not list reads “DO NOT allow dirt and residue to remain on glass for an extended period of time”. Neither line gives a count of days, and neither was written with a party in mind.

So the question before an event is a lead time, and it is answered by working backward: what can reach this glass between the cleaning and the guests, and how quickly does it show. A related but different question, how glass reads in a camera, belongs to whether windows should be cleaned before listing photos.

Five things can put something back on a clean window on this coast, and none of them waits for an event to pass.

• Salt spray. The PGT, CGI and WinDoor care guide names salt spray deposits on its aluminum window frames and warns that wax applied before the frames are cleaned may seal them in, “allowing corrosion to occur”. The guide says that of its own frames, not of the glass, and puts no distance from the water on it.
• Love bugs. UF/IFAS writes that lovebugs “seem to collect on light-colored buildings” and that stronger winds concentrate them against downwind objects, so a pale house during a flight is the kind of surface they gather on.
• Pollen. A fine, dry deposit that settles on still surfaces in the months trees release it.
• Rain. Water that dries on a pane leaves behind whatever it carried or picked up on the way down.
• Sprinklers. A head that reaches a window wets it on every run, and the water dries in place each time.

Sprinkler water is the one agent on that list a household controls directly, which puts the irrigation schedule in the plan for an event alongside the cleaning date. Why it marks glass at all is set out in why sprinklers spot windows.

The agents above do not arrive evenly across the year, and the published calendars for Florida and for Naples show where they bunch up.

The two flights in the table are UF/IFAS's, and the same publication adds: “Higher temperatures cause adult populations to peak slightly earlier in the southern areas of the state.” It also notes that “Their remains can be removed from surfaces easily if not left to bake in the sun.” An event inside a flight is the case where a short gap matters most; how the remains themselves come off glass is the subject of cleaning love bugs off windows.

For pollen, UF/IFAS puts Florida's season at January to June, starting in North Florida and moving south, “peaking in South Florida from February to May”. Why that powder clings to a pane is taken up in whether pollen sticks to windows. The rainy season shows in the NOAA normals above: June through September each carry more than 7 inches of rain, against under 2 inches in December and February. How each surface of a house responds to that year is set out in what the Naples year does to a roof, a driveway and a pane of glass.

The documents read here print two cleaning intervals, and both answer how often, which is a different question from how soon.

NGA's FB01-00 puts its general figure at two cleanings a year and qualifies it in the same sentence: “specific regions may require more frequent cleaning due to environmental factors and atmospheric pollutants.” The PGT, CGI and WinDoor care guide, written for its own windows and doors, sets a separate figure for owners who, in its words, “live in a coastal area”: cleaning the listed materials at least monthly. The same guide adds that more frequent cleanings may be necessary depending on environmental factors.

Neither line says anything about a party, a wedding or a visit, and neither can be stretched into a lead time. A monthly coastal figure shows how much weight that maker gives a coastal site for its own products; it does not say how many days before an event the glass should be done. How often coastal glass needs cleaning in general is argued in frames, drainage and how often coastal glass needs cleaning, and a window maker's own care guide is the document that sets the interval for its product.

With no printed figure, the date comes from reasoning about the house and the season rather than from a rule.

The reasoning runs in one direction. Every day between the cleaning and the event is a day for salt, pollen, insects and water to settle, so a shorter gap leaves less on the glass when guests arrive. How much that matters depends on the calendar: the same number of days sits differently in a dry December week than inside a lovebug flight or a wet August.

A few things in that window are within reach. Sprinklers that reach the glass can be adjusted so they miss it. On PGT, CGI and WinDoor aluminum frames, that guide puts the cleaning before any wax goes on. And the UF/IFAS line on lovebug remains, quoted above, favors dealing with a flight's remains early.