Large amounts of moisture may soak into the pad beneath the carpet. Carpets may come into contact with moisture in bathrooms from these sources:
Wet feet/ wet body dripping on carpet after shower / bath
Condensation from shower steam
Tub or shower water splashing
Water splashes from sink.
Water dripping from the vanity.
Toilet leaks
The presence of moisture in the carpet pad will lead to the growth of decay fungi on the wood or oriented strand board (OSB) sub-floor. The sub-floor will become decayed and weakened by mold. Mold may also releases spores that can could cause respiratory ailments, especially for those with certain health problems. A moisture meter is used during a home inspection to determine if there is excess moisture beneath a carpet.
In addition to potential mold growth beneath the carpet, bacteria can accumulate in carpeting surrounding the toilet.