Technician in a protective suit and respirator cleaning shoes on a rack

Technician in a protective suit and respirator cleaning shoes on a rack. A representative photo of the task, not a record of work at any particular property.

Three layers, three different problems

Most apartment carpet sits on a foam pad over plywood or oriented strand board in upper units, or over concrete on the ground floor. A spill or fluid that sits long enough passes through the carpet backing, spreads in the pad, and then soaks into the subfloor. Each layer needs a different response.

Spills of food, drinks or other liquids, a leaking aquarium or plant, a refrigerator water line, or a slow toilet leak can all leave odor behind. Long-term smoking also loads carpet and pad, though usually across the whole unit rather than in spots.

Picking the response

Start by pulling back a corner of carpet near the worst spot and looking at the pad and floor.

  • IfPad is clean and dry, odor is in the fibers onlyExtraction with an odor-appropriate cleaning solution is usually enough.
  • IfPad is stained or smells in a few spotsCut out and replace those sections of pad, clean the subfloor beneath, and re-stretch the carpet.
  • IfPad is stained across a large part of the roomReplace pad in that room; consider whether the carpet is near the end of its life anyway.
  • IfSubfloor wood is stained or smellsClean, let dry, and seal the stained area with a primer or sealer made for odor before new pad goes down.
  • IfSubfloor is soft, delaminated or moldyCut out and replace the section; check below for a leak that may still be active.

Factors that push toward replacement

Factor
Carpet age
Leans clean
Few years old
Leans replace
Near the end of its expected life
Factor
Area affected
Leans clean
A few spots
Leans replace
Most of a room
Factor
Odor after a test extraction
Leans clean
Gone once dry
Leans replace
Returns as it dries
Factor
Turn schedule
Leans clean
Time for cleaning and drying
Leans replace
Replacement can be installed faster than repeated cleaning
Factor
Planned renovation
Leans clean
No upgrade planned
Leans replace
Unit is scheduled for hard flooring soon

Photos for the unit file

  • Carpet surface with stains visible, under raking light.
  • Pad after carpet is pulled back, with a tape measure for scale.
  • Subfloor stains before cleaning and after sealing.
  • Any leak source found, before and after repair.

Common questions

Does a black light help find spots?

It can help show where some fluids dried, but it also lights up cleaning residues and some fibers. Use it to decide where to pull back carpet, not as proof.

Can hard surface flooring go over a stained subfloor?

It can trap odor under the new floor if the subfloor is not cleaned and sealed first. Seal before any new flooring.

General information for Centennial, not a quote or professional advice. In an emergency, call 911.