Every January, entries across the DC region start to look wrong. Not dirty exactly. Dull, slightly chalky, with a white bloom that shows worst when the morning light comes through the glass. By late February the shine is gone from the first several feet inside the door, and there is a visible line where the traffic pattern ends.
The building was cleaned every single night through all of it.
What the white haze actually is
Ice melt is salt. Depending on the blend it is sodium chloride, calcium chloride, magnesium chloride, or potassium chloride, usually a mix. It comes into the building on shoes, in slush, and as fine dust blown through the door.
Two things then happen, and they are different problems.
The first is physical. Salt crystals are hard and angular. Ground underfoot across a polished surface, they abrasively scratch it. Thousands of tiny scratches do not read as scratches, they read as loss of reflectivity. The floor looks hazy.
The second is chemical. Salt is hygroscopic, meaning it pulls moisture from the air. A floor that looks dry can hold a damp salt film that keeps reacting. On marble, limestone, and travertine, all calcium carbonate, acidic runoff and some chloride blends will etch the surface outright. Etching is not a coating sitting on top. It is the stone dissolved. No cleaning removes it, because there is nothing to remove. It has to be mechanically honed and repolished.
Why nightly cleaning does not stop it
Because the standard response makes it worse.
A crew sees haze and reaches for something stronger. Most general purpose cleaners are alkaline, some are acidic, and plenty of products labeled neutral are not actually pH neutral in use dilution. On calcium carbonate stone, acidic chemistry etches on contact. Alkaline chemistry leaves residue that attracts soil, so the floor looks dirty faster, which invites more product.
Then someone switches to a more aggressive pad. That removes the polish. Now the surface is open and porous, so it holds salt better than it did before.
Six weeks is roughly how long that cycle takes to become obvious to someone who is not looking for it.
Nearly every etched hotel entry we have been called in to restore was damaged in January and February, by cleaning that was happening the entire time.
What actually works
In rough order of how much damage each one prevents per dollar.
Matting, and more of it than you think. The single cheapest floor protection anyone will ever sell you. The guidance most facilities follow is far too short. You want roughly fifteen feet of matting in sequence: a scraper outside, a scraper or combination mat in the vestibule, and an absorbent wiper inside. Most buildings run three feet of decorative mat and wonder why the stone behind it fails. Mats must also be changed or cleaned during the day in winter. A saturated mat is a salt reservoir that reapplies to every shoe crossing it.
Increase frequency, not aggression. The right winter response is cleaning the entry more often with correct chemistry, not once with something harsher. Salt does its damage while it sits.
Use a neutralizing cleaner, and verify the dilution. Specify products by pH at use dilution, not by the word on the label.
Clean up, not just around. Salt collects at the edges, along base, and in grout lines, where a machine cannot reach. That reservoir feeds the traffic lane all winter. Edge and detail work matters more in February than any other month.
Deal with the exterior. If building staff or a landscape contractor is over-applying ice melt at the door, no interior program will keep up. Over-application is extremely common because more feels safer.
The timing that matters
The winter program has to be in place before the first event, not after the haze appears. Once stone is etched, you are no longer discussing cleaning. You are pricing restoration, and the difference between those two numbers on a hotel lobby is not small.
If your entry is stone and you are reading this before October, you are early enough. If it is already February and the floor looks dull, stop using whatever is currently being used on it and have someone identify the material before the next clean.
More reading
How to read a janitorial scope before you sign it
This is written to be useful even if you hire someone else. Most janitorial disappointment is visible in the scope before anyone starts work.
Your lobby floor is failing and nobody made a mistake
There is rarely a single bad decision. There is a sequence of reasonable ones, and the floor is gone at the end of it.
Start with a walkthrough
Fifteen minutes in the building tells us more than any form would. Call, or send the property address and we will arrange a time that works around your operation.