To get rid of mold under linoleum, the linoleum must be removed and the underlying flooring scrubbed with hot, soapy water. It may be necessary to replace the flooring and increase ventilation to the bathroom to eliminate mold.
Determine the cause of the mold growth as an initial step to eliminating the problem. Check toilets, sinks and showers for leaks and make necessary repairs to control moisture in the room. Moldy linoleum should be discarded in the manner determined by local laws and regulations. After making repairs and discarding moldy linoleum, begin treatment to kill mold spores to prevent the problem from recurring.
The Environmental Protection Agency recommends scrubbing the sub-flooring and other areas affected by mold with detergent and water. Undiluted white vinegar effectively kills most mold spores. Vinegar should remain on the floor for 1 hour before scrubbing the floor with detergent and water.
Hydrogen peroxide can also be used to treat mold. Spray a 3 percent solution of peroxide on the area, and allow it to sit for 10 minutes before washing with soap and water. The floor should be completely dry before covering with new linoleum.
To remove mold permanently, use a dehumidifer and increase ventilation in the bathroom. It may be necessary to replace the sub-flooring under the linoleum if the mold is severe. Wood sub-flooring that is warped, appears wet or that is covered in mold should be removed by a mold remediation professional.