Mold - Where and How Does It Grow?

Aaron signed as he sat his soda can on the table.  True to form, he couldn't finish a drink before it hit his bladder.  Excusing himself from the room, he quietly went to the bathroom.  The door was locked.  "Must be one of their kids," he thought.  Maybe John and Sarah wouldn't mind if he used their master bath, since he had about 30 seconds before the filtered soda would leave his bladder, whether he was in an appropriate spot or not.

As he closed the door and lifted the lid, Aaron noticed the dark staining on the wall and on the baseboard behind the toilet.  "What in the world?" he muttered, and then he recognized that it was mold.  Growing along the wall, it was all the way from the vanity to the tub.  It gave him the chills to know that his best friend lived in such filth.  He quickly finished and gratefully closed the door behind him as he eagerly returned to the party, thinking of any excuse to leave as soon as possible.


Mold requires 3 ingredients to grow; mold spores, moisture and a food source.  Once all three components are in place, mold can begin to grow most any place.  All homes and businesses, regardless of how clean, have mold spores and food sources readily available.  All that is missing is the moisture for growth to start.

While mold can grow in nearly any location in your home, there are a few places where it is much more likely to start.  Regular inspection of these places will help to prevent or reduce mold growth.  Regular means daily if you are paranoid, or once a week to once a month if you are conscientious.

1. Under sink cabinets - Sink cabinets always have water lines.  It is possible for a small or large leak to begin most anytime in either the supply or drain lines.  The older the plumbing, the greater the chance of a leak forming.  They can occur from old gaskets, rusty pipes, or worn-out fixtures, etc.  Once a pin-hole leak starts, the water will erode the hole larger and larger until a drip every day becomes a steady stream.  Because we seldom inspect under the sink, mold can grow undetected for quite some time.
2. Behind and under your fridge - Water and ice lines to the fridge are fragile.  They are usually 1/4" lines of either plastic or copper tubing.  As the fridge is moved in and out for cleaning and inspection, it is easy for the tubing to be crimped or run-over by the wheels, causing a small hole to develop.  Movement and vibration also loosen the fittings, allowing water to leak out.  A slow, steady drip can become an adequate source of moisture for mold growth and remain unnoticed for weeks.
3. Around tubs or showers - In these locations, there is soap scum and bodily oils that collect in corners.  These are food for mold to grow.  If the shower is wiped down or cleaned regularly and the room is properly exhausted, you can minimize mold growth.  Also, over time, the joints and corners of tile and cultured marble surrounds, develop cracks.  These will allow water to seep into the framing under the shower and start mold growth under and between floors, as well as onto ceilings below.
4. Exterior windows and doors - Windows, especially in the colder climates, are frequent haunts for mold.  Dust and water condensing on the glass collect on the sills and provide a perfect environment. This is particularly true when heavy drapes and curtains are over the windows and seldom if ever opened allowing the moisture to build up and condense.
5. Around any other water fixture, i.e.; toilets, water heaters, boilers, swamp coolers, etc. - The older the home, the more likely a leak can begin.  Water heaters have warranties that range from 5-12 years.  They are usually pretty good at not lasting much longer than the warranty.

Here are a few of the less likely places I have seen mold grow.

1. Attics - If you have a leak in the roof, the water will provide the environment for mold to grow.
2. Crawl spaces - Some locations have extremely high ground water.  This water can condense on the framing members and start mold growth.  Venting crawl spaces as per code, as well as installing moisture barriers on the dirt, will greatly reduce the chance of this happening.
3. Between the layers of vinyl flooring - Often the wax ring that seals the toilet to the drain will develop a hole allowing water to seep out along the sub-floor, under the vinyl.  When this water penetrates the layers of paper in the vinyl, mold can grow.  This generally creates a grey to purple stain in the flooring.  It looks much like someone spilled grape juice and it stained.  No matter how hard you scrub or what cleaner you use, the stains will not come off.  The only solution is the vinyl has to be replaced.
4. Sub-flooring under wood or laminate flooring - In the event of a water leak or flood in a room with laminate flooring, the foam or plastic barrier under the laminate will trap moisture next to the sub-flooring material, allowing mold to grow.  Often it takes months to years for this water to dissipate.
5. Exterior walls behind furniture - Mold in these areas usually grow from one of two sources.  First, water intrusions from the outside such as sprinklers or rain water.  Second, high humidity in a room that condenses on the cooler locations behind the furniture near the floor.  Either of these reasons need to be corrected before effective remediation can occur.

Regardless of where or how mold begins to grow, the guiding principles of remediation are:

• Correct the source of water.  If the source is not stopped, mold will begin to grow again within a few weeks of the repairs.
• Remove and dispose of all damaged material.
• Wipe and HEPA vacuum the area until clean.

Tips to Prevent Floods and Water Damage

Sarah stood ankle deep in cold water. A child’s toys floated by. Across the family room, water cascaded over the window sill and spilled onto her new carpet. The piano, her new sofa and the big screen TV were all submerged. Why did this happen and what could she have done to prevent it?

There is no guarantee that you will never have a flood or water damage in your home, but there are some tips to prevent them. I have listened to frustrated customers passionately tell me that they will never leave their home again without turning off the main water line. This would be effective if all floods only occurred while the home was empty. You would also need to have the City turn off the water lines and sewer drain lines to the neighborhood. Oh, and how do you convince God to never let it rain while you are gone?

In truth, most water losses occur while we are in our house using the water. It is characteristic that a valve or fitting ready to fail will do so as the water is turned off.

The water lines in your home generally have 40-60 pounds per square inch (psi) of water pressure. This pressure is the force that pushes the water out of the faucet when you use it. If the water is turned on, the pressure in the pipe drops to nearly zero. As the water is turned off, the pressure instantly jumps back up to 40-60 psi. This sudden increase in pressure from 0 to 60 pounds is enough change to break the weak link in your water system that has been waiting for just the right opportunity.

Because there is no way to totally prevent water damage, we need to concentrate on the preventative measures we can take to limit our exposure and risk. The best method is inspecting your house regularly to find the potential break-before it does break. It doesn't mean you need to take a flashlight and a clipboard and crawl around the house every Saturday morning, because we all know that will not happen.

The best form of inspection is to simply be aware.

• When you turn off a faucet, does it drip?
• Are there white or green deposits on valves, pipes or other water connections?
• Is the floor of the sink cabinet damp or show signs of water damage?
• Is the grout or caulk in the tub or shower chipped, missing or have black discoloration?
• Is there a rusty stream of water or rusty stains coming from under your water heater?
• Are there rust spots on the carpet when you move a piece of furniture that has metal legs or gliders?
• Are there blisters or bubbles in the paint or drywall tape on the walls, especially on outside walls?
• Do you notice a musty odor in any room of the house, especially in the basement?

A "yes" to any of these questions indicates you have or will have a water problem. The size and cost of the problem is directly related to how quickly you remedy the situation. Procrastination will always increase the costs and in some cases, void your insurance coverage. Learn to be pro-active in maintaining your home by being observant and aware. As you are able to prevent water damage, you will find yourself saving money, time and resources.