It is not possible to kill mold in carpet; instead homeowners must fix water problems and then scrub away remaining mold, remove the carpet and install new carpet. The mold cannot be "killed" on the carpet because carpet is absorbent and porous, meaning that a moldy carpet has mold inside of the fibers.
The presence of water problems is usually what causes mold so all water problems, such as leaky pipes, must be fixed first. Then, mold must be removed from any hard surfaces, such as wood floor or metal kitchen sinks. The carpet must then be pulled up and removed. This includes the carpet padding. The area should be dried and then new carpet should be installed as well as a new carpet pad. It is important to choose high-quality pads that can withstand minor amounts of water damage in the future without mold growth.
The easiest way to "kill carpet mold" is to prevent it from existing in the first place. Once the mold that is there has been removed, homeowners should take precautionary measures to ensure that mold does not re-emerge. These steps should include reducing indoor humidity to between 30 and 60 percent, to keep carpet out of areas such as bathrooms that are prone to high humidity temperatures and to use high-quality padding for all carpeted areas.