Mold Under Wet Carpet: Signs, Timeline & Fix

A wet carpet from a burst pipe, a leaking washer, or heavy rain creates an immediate clock with a start time. Moisture sealed between the fibers begins to ruin the padding and subfloor and provides a growing substrate for mold. This can happen weeks before anything shows up on the surface.

Signs of mold growth beneath a carpet can manifest in several ways. For example, a musty smell resulting from mold growth can permeate the entire room. Mold growth will also cause the carpet to stain, and if the pad underneath the carpet is also moldy, pressing on the carpet may result in mold spores being released and visible as fuzzy black growths.

The biggest threat to your flooring and indoor air quality is time – if you find yourself with standing water, or calling in a service like Carpet Cleaning in Burlington, working quickly is essential.

Indoor air contains mold spores, which are completely harmless until they find a nutrient-rich, damp place to land. Mold needs a consistently dark and still environment with its food source – that means your wet carpet is the perfect breeding ground.

The backing of your average carpet can contain either jute or latex, and the padding contains a dense layer of polyurethane foam. When saturated, that foam acts like a giant sponge and creates a barrier to moisture evaporating from the bottom – so there is a lot of trapped moisture against your floor.

The fibers of your carpet trap all kinds of particles like skin and even pet dander, which provide a continuous supply of nutrients for the spores. After a while, the moisture spreads to wood, drywall, and even baseboards, turning a localized issue into multiple structural issues.

The speed of this process depends on a couple of different factors:

What the water came into contact with:

Water from a burst pipe means you have 24 to 48 hours to complete the restoration process. Contaminated water from a sewer backup or drain overflow contains all kinds of bacteria and organic materials that can start to grow and spread mold almost as quickly as the moisture does.

Padding density:

The densest materials for padding (such as memory foam) retain the most moisture, most notably in dense rubber padding. The moisture can soak subfloors for several days if the carpet is not removed.

Room conditions:

The spores will begin to grow and multiply in rooms heated between 21°C (70°F) and 32°C (90°F) with closed windows and no airflow. Moisture will just stay trapped.

During early stages of growth, mold can develop not only on the pad but also on the subfloor. Traditionally, people will look at the carpet fibers, but that will not be helpful, especially in these early stages. Look for these instead:

• Musty, sour smell:

  If there is a smell of dampness that almost resembles earth, that will be mildew, and will be growing in the pad beneath.

• Discoloration Along Seams or Edges:

  A dark brown, black, or green discoloration either alongside baseboards or seams of the carpet most likely is caused by moisture being drawn through the backing of the carpet.

• Squishy Padding:

  Padding that has been saturated will cause an uneven and soft feeling when stepped on.

• Bubbling baseboards:

  Moisture drawn from subfloors will cause the paint near the floor to bubble up.

• Indoor allergies:

  If there are no previous allergies, and you find yourself becoming allergic when in that room, it is a good sign that there are spores being released from the subfloor that are causing the allergic reactions.

If any of these signs sound familiar and you’re not sure who to call, this guide on how to choose the right carpet cleaning company walks through what to look for.

Improper treatment of damp carpet padding is not only a safety and health risk when walking on wet carpet, but it can also adversely affect indoor air quality. The mold and mycotoxins can spread freely as the carpet is walked on, and the spores and mold can become airborne. This can cause serious respiratory illnesses in you and your family.

The carpet mold, spores, and mycotoxins can cause persistent runny noses, constant sore throats, and may even cause asthma attacks for children and elderly family members.

Clean water spills, if dealt with quickly, can be dried out with basic equipment.

1. The source that is leaking must be repaired before all water is removed.
2. A wet/dry shop vac should be used to pull as much water as possible from the carpet and pad.
3. Using a pair of pliers, you can remove the carpet from the tack strips on the edge of the affected area. Fold the carpet back to expose the pad and below floor.
4. Before replacing the carpet, the subfloor and backing should be sprayed with a diluted disinfectant (hydrogen peroxide) because bleach can damage the backing and corrode tack strips.
5. With the carpet lifted, place high-velocity fans aimed across the subfloor. Use a dehumidifier in the room to pull the moisture from the air. Keep the fans until the pad and subfloor are completely dry.
6. Secure the carpet to the tack strips. Use a vacuum with a HEPA filter to clean up loose dirt from vacuuming.

For small, clean water spills you can catch early, a shop vac and some patience will do the job, but for anything larger it helps to know what works better, professional cleaning or rental machines, before you decide how to handle it. 

Professional teams use advanced commercial tools, such as:

• Units with infrared cameras and moisture meters:

  These tools obtain moisture maps behind walls and in deep subfloors without the need to open any wall surfaces.

• Truck-mounted pumps:

  Remove carpet backings and padding that houses are unable to reach with vacuum cleaning.

• Heavy-duty air movers and LGR dehumidifiers:

  Air movers move air at high speeds over moisture, and LGR dehumidifiers evacuate water from air at a rate of many gallons per day.

• HEPA air scrubbers:

  During mold remediation, isolation barriers and negative air pressure systems are in place to keep mold spores from spreading.

• Deep sanitization of the subfloor:

  Technicians can use a treatment, sanding, or sealing of the subfloor to prevent mold from growing back under new padding.

These tools are one of the main reasons professional carpet cleaning in Burlington gets results a homeowner can’t match on their own. 

It is best practice to catch room humidity issues and carpet mold development as early as possible to minimize the potential for damage.

• Deal with drips from plumbing, seal condensation on windows, and seepage from basement walls as soon as you notice them.
• Keep indoor humidity below 50 percent by using an AC or dehumidifier.
• Use exhaust fans in basements, laundry areas, and bathrooms to prevent moisture from settling on hallway carpets.
• Schedule annual professional carpet maintenance to remove dust to prevent mold.

Even Cold months bring their own moisture problems, so it’s worth reading our winter carpet cleaning tips for Burlington homes to keep humidity in check year-round. 

There are times when restoration is not financially helpful. It is best to replace the carpet and padding when:

The water source was contaminated:

Flooding from sewage backups, toilet overflows, or river runoff can introduce contamination, which makes padding impossible to sanitize.

The carpet was saturated for more than 48 hours:

After two days, fungal hyphae start to penetrate through the primary and secondary backings and cannot be removed completely.

Delamination of the carpet occurs:

Water destruction of carpet padding also breaks the synthetic latex glue, which causes the padding to buckle permanently

If you do end up calling in a crew, a little planning goes a long way. Here’s how to prepare your home for professional carpet cleaning so the visit goes smoothly.

Wet carpet can grow mold within 24 to 48 hours. Musty odors and spongy padding are signs that can signal you to pull up carpet to dry the subfloor to avoid expensive structural repairs.

When a large-scale flooding event occurs, it is best to lean on a reliable team for the assurance that you are not overlooking key steps in the restoration process. For over 20 years, Aberdeen Carpet Cleaning has provided Burlington and its surrounding area with flood restoration, complete floor care, and emergency response services including carpet, area rug, and upholstery cleaning. Additionally, we provide pet stain and odor removal and restoration of commercial and residential carpet and fabrics. Please call us to come inspect your flooring, remove trapped water, and improve the air quality inside your home.