Can’t figure out where the moldy, musty, earthy smell in your home is coming from? Try looking under your flooring. Mold growth is easy to see on walls, tubs, grout, etc., but it is more difficult to spot if it grows under your floor covering. Mold grows anywhere when the right conditions are present.
Signs Of Mold Under Flooring
Mold is responsible for health problems such as asthma attacks, breathing issues, runny noses, coughs, and more. You don’t want mold in the attic, mold in the basement, and especially in living areas. Here is what to look for.
- Musty Odor. Musty odor without visible signs of mold. Especially if confined to one room.
- Damp Spots. Damp spots on flooring that never seem to dry.
- Discoloration. Watermarks or discolored spots.
- Warping or Lifting. All types of flooring react to mold beneath them by eventually lifting or warping.
- Spongy Feel. If the mold infestation grows thick enough or floor boards lift enough, the floor may feel spongy.
- Mold on Walls. Close to the floor or on baseboards.
- Observation. Pull up the flooring where you suspect mold growth to look at the subfloor and backside of the flooring.
- Rotting Subfloor. Check subflooring from the basement–especially around plumbing penetrations–for signs of mold, rot, or leaks.
Causes Of Mold Under Flooring
Mold spores settle on organic material–like wood and dust–but remain inert until moisture is added. Leaks, spills, and high humidity all lead to mold growth under flooring. Once moisture gets under the flooring, it is difficult to remove. Subfloor and floor coverings like wood, laminate, and carpet absorb moisture. Many types of flooring prevent evaporation–especially in poorly ventilated spaces like basements.
Small unnoticed leaks from plumbing penetrations, toilets, and condensation running down pipes provide enough moisture to start mold growth. Spills that are not wiped up soak into or through the flooring. High humidity areas–like bathrooms, kitchens, and basements–encourage mold growth–especially if poorly ventilated.
Mold growth often starts on baseboards and walls near the floor. If left unchecked, it migrates under the flooring. The reverse is also true. Mold that starts under the flooring can migrate up the walls and into insulation and stud cavities.
Removing Mold From Under Flooring
You can buy mold testing kits online or from home improvement outlets. They indicate the presence of mold, but eventually, you have to remove some of the flooring to confirm mold growth.
Different types of flooring require different solutions but the basics are similar.
- Expose all of the mold.
- Remove mold growth from the flooring material and the subfloor using 50/50 vinegar/water solution. (Spray bottle and brush)
- Allow everything to dry thoroughly.
- Find the water source–leaks, drips, condensation, or spills–and prevent it from happening again.
- Replace the old flooring or buy new material.
Wear personal protective equipment including a respirator. Make sure you get rid of all of the mold. Replace any rotted subfloor. Hire a mold remediation company if you are uncomfortable dealing with mold.
