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 onlyThenExtraction with an odor-appropriate cleaning solution is usually enough.
- IfPad is stained or smells in a few spotsThenCut 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 roomThenReplace pad in that room; consider whether the carpet is near the end of its life anyway.
- IfSubfloor wood is stained or smellsThenClean, 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 moldyThenCut out and replace the section; check below for a leak that may still be active.
Factors that push toward replacement
| Factor | Leans clean | Leans replace |
|---|---|---|
| Carpet age | Few years old | Near the end of its expected life |
| Area affected | A few spots | Most of a room |
| Odor after a test extraction | Gone once dry | Returns as it dries |
| Turn schedule | Time for cleaning and drying | Replacement can be installed faster than repeated cleaning |
| Planned renovation | No upgrade planned | 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.