A Moldy Situation

Advice and help are always available on the John Bridge Tile Forum.


By Juan F. Garcia

Of the many hazards that face us in remodeling projects, none seem to be more misunderstood than properly managing and cleaning up mold. This article will attempt to provide an inclusive source of information on mold; starting from a description of mold, why it is a problem, why it is prevalent in showers, proper cleanup and how to prevent it from coming back.

What is mold?

Mold is usually seen as the blackish green stuff growing in that forgotten container of leftover food in the back of your refrigerator. You know the one, last month’s dinner with the neighbor’s, or the bag of fruit that the kids were supposed to throw away last week. How did it get there? It certainly wasn’t there when you put the food in the refrigerator. Or was it?

Mold is a naturally occurring organism and an essential part of the decomposition and decay of organic matter. Mold is a member of the fungus family, the same as mushrooms. It thrives primarily in moist and warm environments, however it can even be found in cooler temperatures such as in your refrigerator. Its tiny spores are ever present in the air, and it only takes one spore, with the right conditions to begin to multiply. Once present on organic matter, mold spores, like seeds, begin to germinate and grow. The result is the slimy or fuzzy stuff seen on the surface. It can range in color from white to beige, brown, black, red, green and purple.

Why is mold a problem?

Regardless of what you may have been told, mold, in and of itself, is not toxic. The “toxic black mold” as seen in the media and regurgitated by some businesses is a way of duping the uneducated public into a panic. Certain types of mold, however, can produce substances known as mycotoxins, which are toxic. Ingestion, or eating, of mycotoxins is known to cause illness.

Molds have been known to cause some health problems. Allergy like symptoms such as congestion, sneezing, irritated nose, throat, and eyes, and coughing may have been attributed to inhalation and/or ingestion of mold or mold spores. Some individuals, when exposed, show no symptoms at all. Young children, the elderly, those suffering from asthma, and those with suppressed immune systems may be more susceptible to sickness from mold exposure. The exposure limits to mold for certain health effects are not conclusive; hence, it is not specifically regulated under OSHA.

Mold is not only unsightly; it is also a problem in building systems due to its primary purpose, to decompose organic matter. Mold laden building materials such as plywood subfloors and floor/wall framing can deteriorate beyond usability and require replacement. Severely deteriorated building systems can affect the structural integrity of the entire structure. Many times the effects of the deterioration are hidden behind walls or under surface materials and are not discovered until there is a problem.

Why is mold prevalent in showers?

Besides the refrigerator, mold’s next best environment for growth is in a bathroom. What better place to grow than in a warm and moist environment. Perhaps you have seen some mold growing around the bathroom. Maybe somewhere in the far corner, or up on the ceiling where you normally don’t clean. Just as in your refrigerator science experiment, mold has gotten in there, uninvited. Could it also be hiding behind your shower walls?

Have you ever calculated how much “rainfall” your shower gets per year? If you take one 12 minute shower per day in a 48 inch x 48 inch shower and your shower head flows at 2.5 gpm (gallons per minute), you have almost 1100 inches of rainfall equivalent per year – in your shower! Rainforests do not get that much water and look at the fungi that grow there. Is your shower designed to withstand that type of water exposure? Unfortunately, many poorly constructed showers are prevalent in homes today.

What is the proper way to clean mold contamination?

Surface molds, the types seen in many bathrooms, are easily handled with over-the-counter disinfectants and can then be wiped away during routine cleaning. If your cleaning is not so routine or you have mold problems from a flood or a poorly designed shower, here are some guidelines to follow for proper cleanup. As with all cleanup operations, you need to consider your skills, your liability, and your patience. In some cases, it is advisable to hire a professional contractor who has the experience, training, and equipment to properly clean up the mold.

Assuming you have stopped the cause of the moisture where the mold is growing, the first order of business in mold remediation is wearing proper personal protective equipment. At a minimum you should have an N95 respirator, rubber gloves, and splash proof goggles. Depending on the severity of the mold contamination, a full face air-purifying respirator may be needed, and a full body protective suit can be worn.

Secondly, all remediation should be done using wet methods such as a sponge or mop and a wet/dry HEPA filtered vacuum. The key with these tools is to eliminate getting the mold and mold spores airborne. Obviously, water will be the primary “wet” tool along with some type of disinfectant. There a number of commercially available disinfectants on the market, but most sources suggest a chlorine bleach solution with a ratio of 1 cup bleach to 1 gallon of water. Water takes the shape of its container so controlling cleanup water may be the next step in the remediation process. Heavy (6 mil) polyethylene plastic sheeting properly taped to floors, walls, and ceiling is one way to contain the overflow of contaminated water and cleanup solution.

Another recommendation in mold remediation is creating a containment barrier, usually of heavy (6 mil) polyethylene plastic sheeting that isolates the contaminated area from the rest of the dwelling. This setup may require airlock type chambers and negative air filtration units. If the mold is so severe or widespread that this type of containment system is needed, it’s probably time to hire a professional.

Lastly, if the mold cannot be adequately cleaned up, or the building material is beyond salvaging, it is best to remove the building material and rebuild with new material. Any material that is severely contaminated with mold should be carefully handled, wrapped in plastic sheeting or heavy garbage bags to avoid spreading contamination, and properly disposed of.

How do you prevent mold from coming back?

Now that you are educated and have properly handled your mold problem, the final step is to prevent mold from growing again. If your dwelling has required some remodeling, now is the time to rebuild using industry specific techniques and modern materials. A properly constructed shower that utilizes surface applied moisture barriers is becoming the widely accepted method for controlling moisture at the surface and eliminating the buildup of moisture in hidden areas.

Since mold is ever present in our environments, the best solution is to reduce the moisture on the building material where the mold likes to grow. Next to proper construction, here are some steps that will prevent any future mold problems.

1. Wipe or squeegee water from surfaces.
2. Install a fan or dehumidifier in locations where moisture is a problem.
3. Clean surfaces weekly with a disinfectant.
4. Check surfaces monthly for cracks, chips or gaps where water may collect.
5. Fix any problems on those surfaces or where discoloration beneath surfaces is seen.









Juan Garcia is the proprietor of Redrock Tile and Stone in Loa, Utah. Redrock Tile & Stone is a small business focusing on residential and commercial tile installations with an expanding business model in granite fabrication and installation. Mr. Garcia holds a Bachelor of Science degree in Industrial Technology with a safety specialization and brings eight years of safety and health experience, 10 years of technical research and consulting, and five years of contracting experience to the construction industry. He can be reached through his website at http://www.redrocktilestone.com

Disclaimer: The purpose of this article is to provide the reader with a basic understanding of health and safety issues related to the topic. The reader assumes full responsibility for their own actions and will not hold the author liable or responsible for the accuracy, completeness, or usefulness of any information, product or process disclosed in this article or for any injury or illness to themselves or others arising from information derived from this article.

Opinions offered on John Bridge.com are just that – opinions. The operators of the site assume no responsibility in regards to those opinions.

— John Bridge & Associates, LLC

Tile Your World Logo ©2013 John Bridge and Associates LLC - All Rights Reserved