A polished concrete floor that smells is telling you something is in the pores or under the slab. Sealing the surface traps the smell and typically makes it worse in warm weather.

Source map

Odour	Likely source	Action
Musty, damp	High slab moisture, no vapour barrier	Moisture test, mitigation plan
Urine	Animal or human urine in pores	Enzymatic clean, then densify and seal
Chemical	Residue of cleaner or sealer	Strip and rinse
Sour, adhesive-like	Old adhesive residue under finish	Grind to clean concrete
Inconsistent, room-specific	Drain, trap or subfloor issue	Plumbing inspection first

Diagnostic steps

1. Smell at floor level in several rooms; note whether it rises after cleaning or after rain.
2. Test moisture with a sheet or calcium chloride; record relative humidity.
3. Lift a small inspection patch at a joint to check for adhesive or organic residue.
4. Check drains and traps before blaming the slab.

Treatment by cause

Urine: enzymatic cleaner with dwell time, extract, repeat until the test area smells clean when wet, then densify twice and seal. Moisture: a breathable treatment or a vapour-retarding system, not a film sealer. Chemical residue: strip with the correct chemistry, rinse twice, dry fully.

What not to do

• Do not apply a sealer to mask odour; it traps the source.
• Do not use chlorine as a deodoriser; it reacts with organics and can create new odours.
• Do not steam clean to "sanitise"; heat drives odour deeper.
• Do not polish over an odour source; polishing closes the pore and locks it in.

Prevention

In new builds, confirm the vapour barrier and cure the slab before densifying. In clinics and kennels, clean within minutes and specify a sealer rated for organic load. Odour complaints are a maintenance signal, and the fix is usually upstream of the floor.