Carpet and underlay

Can conceal dampness, odors and residues beneath a dry-feeling surface.

What changes first

Look for musty odor, staining and tack-strip corrosion. The pattern and location usually matter more than color alone.

Moisture and movement behavior

Record whether the material changes after rain, water use, heating cycles or seasonal humidity. A material can display the damage while the source is somewhere else.

Before repair

Determine whether the material is the source, a pathway or only the final surface. Correct the controlling condition before replacing finishes.