Other than just having a high humidity level in the home (due to humid climate), water leaks and other forms of water intrusion into the home or building is the most common reason a toxic black mold problem originates. Below are types of water leaks and places where unwanted water can enter the home, and ways to avoid these types of water intrusion problems. Leaking Pipes: Condensation or rusting on or around a pipe is a sign of a leak. Covering cold surfaces, such as cold water drainpipes, with insulation helps to prevent condensation. The most difficult part of preventing leaking pipes is determining whether or not they are leaking in the first place, since they are normally concealed from view.

Here are some signs to look for:

• Water Meter Spins when nothing is turned on.
• Musty odors that seem to originate from ceiling, walls or floors.
• Running toilets and dripping faucets.
• Abnormally high water bills.
• Peeling Paint.
• Discolored or damaged walls.
• A cracked or damp foundation or slab.
• Warm spots on concrete slab floors, mildew, or excess moisture under carpets.
• Regular sewer backups.
• Areas in the yard that are too wet and with unusual plant or grass growth.

 Foundation

To prevent water from collecting around the foundation, and seeping up through the walls, make sure the ground slopes away from the foundation. Here are some additional tips in preventing water seepage through the foundation:

• 1. Ensure the floor is well ventilated and walls are properly sealed against moisture entry. Polythene put over damp ground can help prevent dampness rising into the house.
• 2. Insulate your home properly. In the winter, insulated ceilings, walls and floors have temperatures similar to those of the warmer air inside the home, therefore condensation is less likely to form.
• 3. Prevent rising damp from entering a foundation wall by improving your home’s perimeter drainage. Direct all surface rainwater away from the home through drainpipes, culverts, French drains, etc.
• 4. If no other methods are feasible, a last resort would be to install either a physical or chemical horizontal damp-proof course.

Roof

• A common cause of leaks is from cracked or damaged chimneys. Look for loose brick, cracked mortar joints, and a solid metal or concrete cap on top. Look for water stains on the inside ceiling, and on the beams in an attic. Beams that have been exposed to water will become weakened and cause a sag in the roof. Look for any visible damage such as cracks, tears, splits. These will most likely lead to leaking. Closely inspect all roof penetrations (i.e. skylights, chimneys, vents, etc). Look for signs that the cement is separating from the surface, especially at a vertical penetration of the roof. Check areas where different materials meet such as metal to brick, shingles to metal, etc. These surfaces expand and contract at varying rates and will pull away from each other. Make sure the seals between materials are tight, not loose. You can attempt to find a leak from the inside by using a flashlight and tracing the leak uphill.
• Protect/Maintain the Roof. Inspect your roof at least twice a year. Especially proceeding harsh weather conditions and between seasons. Roofs will weather under the heat/sunlight. It can essentially be “baked” and become dry and brittle, it is more likely to split and eventually leak. Metal components of the roof can rust and corrode, and asphalt-based plastic cement used for seals around pipes, vents, and other penetrations may deteriorate over time and leak. You can apply a coating to some roofs to create a layer of waterproof protection.
• Ice Dams and Leaks. Leaks caused by ice dams occur when warm, heated air from the home begins to migrate through the insulation and into the attic area of the house. Without proper ventilation, this warm air collects in the attic area and may warm the underside of the roof decking. Cold outside temperatures keep the top outside layer of moisture frozen and the warm decking melts the bottom layer of ice turning into liquid water. This water will run down the shingles until it meets the "dam" at the gutter line. With no escape route, the water pools, then backs up underneath the shingles and enters the attic area through nail holes and seams in the roof decking
• Ways to Minimize the Occurrence of Ice Dams. Keep the attic adequately insulated. Do not cover the attic soffit air intake vents with insulation. Ensure attic has sufficient air exhaust outlets and airflow is distributed evenly throughout the attic. An ice and water shield can be installed at the eaves of the home and under the shingles to prevent water from entering the home. Install electric heat tapes in the gutter system. Windows: Condensation on or around the window is the sign of a excessive moisture. If this is happening, use a sealant around the window to make sure that it is completely air tight. Walls: Taking measures to reduce water leakage through the roof, leaky pipes, and the foundation, as well as through the gutters (below) will go a long way in keeping the walls from collecting too much moisture. In addition to this, make sure that the air pressure is not too high on the positive side. However, you do want the air pressure inside to be slightly positive. Also, make sure that the relative humidity level is below 55% to prevent your walls from taking in too much moisture. Use dehumidifiers if necessary. Gutters: Clogged or faulty rain gutters can cause excessive water leakage through the walls, roof, and foundation of the home. You can clean your rain gutters with a light broom, a garden hose with a controllable-spray nozzle, or by using one of many gutter-cleaning devices on the market. Adding perforated covers over your rain gutters will cut down on the frequency of cleaning. Rainwater and some dirt/small debris can permeate the cover but large debris, such as large leaves and twigs, cannot. These covers can typically be found in a local hardware store for only a couple of dollars for about every 4-feet of length. Make sure your gutters' downspouts are properly cleaned too. Spray water into the gutter or the top of the downspout to ensure it drains freely and with no obstructions. Water must also be diverted away from your home's foundation. If you don't have a spout going directly into a drain system in your yard and toward the street or a drainage basin, use splash blocks. These relatively small devices will channel the water from your downspout and away from your home and only cost a couple of dollars.

Basements/Crawl Spaces

Click here for more on basements and crawls spaces. Basements / Crawl Spaces

• Put a plastic cover over dirt in crawlspaces to prevent moisture from coming in from the ground. Be sure crawlspaces/basements are well ventilated with good cross ventilation under the house so air will circulate freely. Make sure all vents are unobstructed and repair any torn vent screens. If you don’t have sufficient vents, add more.
• Get your basement waterproofed through a professional service: http://www.basements.com/ http://www.housingzone.com/topics/kocht/cmaterials/koc01cv006.asp http://www.xypex.com/ http://www.radonseal.com/ - Seal you concrete yourself against water and vapor with RadonSeal deep-penetrating concrete sealer
• Building construction practices to prevent moisture in a new home, particularly in the basement: Site selection. The first and perhaps most important step is to select a suitable site. Moisture problems are greatly reduced if a home is built on a site with a high water table. Surface drainage. Landscaping should be graded/sloped to direct rainwater and melting snow away from the foundation. At least six inches over the first ten feet from the foundation wall. Dampproofing. A dampproof coating on the below grade portion of the foundation wall. Tell your builder you want a high quality, durable waterproofing. A thin dampproof coating is vulnerable to damage during construction. Floor slab. The basement floor can be a significant source of moisture. To reduce water absorption, the concrete slab should be poured on top of three to four inches of washed aggregate, with a sheet of polyethylene installed beneath the aggregate. Insulating the floor slab saves energy and improves comfort; it also reduces basement condensation in the summer. Drainage system. An effective exterior drainage system drains bulk water away from the foundation. A channel of coarse rock or drainage tile may be used. The drainage system must be installed on the outside, and near the bottom of the footing Foundation wall insulation. Foundation insulation may be placed on the exterior wall, be an integral part of the wall, or placed on the interior of the foundation wall. Regardless of where the insulation is placed, a moisture barrier is required to reduce outdoor moisture from coming through the foundation wall. In the case of insulation placed on the interior side of the foundation wall, both sides of the insulation must be protected. A moisture barrier is required between the insulation and the wall from floor to grade, and a vapor retarder is required on the interior side of the insulation.
• To keep water out of crawlspaces, dig ditches around the sides of the house down to the footing. Install gravel and drain lines that are sloped about 2 inches per 10 feet to carry water away from the house. Direct the water to a natural drainage, to the street, or a French drain. Before backfilling, place waterproof membranes against the foundation wall. Also, ensure water from downspouts is directed away from the house. Ductwork / HVAC System Sanitize Cooling Coils Make sure you periodically wipe any biological growth from the coils. Condensation is continually dripping off the coils when the HVAC system is running. This condensation provides a perfect place for mold to grow. In which case, disinfectant should be periodically applied to the coils. Drain Pan This is where the condensation from the cooling coils drips. If you have a flat drain pan, the stagnant water will become infested with mold growth. In which case, a sloped drain pan should be used, so the water runs off to the proper location. You also need to check to make sure that drain lines are flowing properly. In addition, the drain pan should be cleaned with a disinfectant on occasion, and should be replaced when corrosion becomes significant. Filters Change your HVAC filters on a regular basis. If this is not done, the filter itself can become a fertile breeding ground for all the molds and other biological contaminates that are collected. Once this happens, the spores from the mold will multiply, and will be circulated throughout the home or building through the ductwork. Insulation If you have insulation lining the interior of the ductwork, then it should be removed, so you are left with bare sheet metal. The fiber glass insulation collects a lot of dirt and dust, which provides a good habitat for mold colonies. Once the mold begins to grow inside the ductwork, the mold spores will be spread throughout the house when the HVAC system is running. Cleaning Mold in the HVAC System New Construction In many cases, mold problems can be avoided or caused during the construction of a home or building. In which case, you can take precautions during this phase to save yourself mold headaches down the road. First, review many of the tips on this page to make sure that the house is built in such a way that as many of these as possible can be put into place. In addition, avoid using moldy materials, ensure that any fake stucco that is used is installed 100% properly, since this is a common cause for mold growth in exterior wall cavities. If you are really adamant about preventing potential mold problems, then you may want to avoid using fake stucco altogether. Dirt / Dust Removal An environment that is "dirty" or "dusty" is far more conducive to mold problems than a clean environment. Dirt, dust, and grime are often composed of organic material, which is a staple of the the toxic "black" mold diet. House dust also serves as a means for locomotion for mold spores, enabling them to spread throughout the home more effectively. Ventilation Proper ventilation can reduce moisture in the home. Keeping the air pressure in the home or building at a slightly higher level than the air pressure outside will help to ensure proper ventilation. Slightly positive air pressure forces moisture and contaminates outside. If the air pressurization is the other way around (negative), where the air pressure is higher outside, then it will force moisture and pollutants back into the home or building. Avoid over-pressurization though (too much of a positive air pressure), since it will cause moisture to be forced into walls and structural cavities, compounding the moisture level inside, and potentially damaging the home or building. In order to achieve a slightly positive air pressure, adjust the supply ventilation slightly higher than the exhaust ventilation. Also, try to ventilate appliances and bathroom/kitchen fans outside if possible. Properly Vent Combustion Appliances Combustion appliances include space heaters, ranges, ovens, stoves, furnaces, fireplaces, water heaters, and clothes dryers. Typically these appliances are safe. However, the combustion process always produces water vapor, if the appliance is not properly vented, it can lead to increased amounts of moisture in the home and provide an ideal environment for mold growth. Examples of properly venting combustion appliances include equipping ranges with hood fans that are exhausted to the outside, keeping doors open to rooms where these appliances are operating, making sure that the vents are connected and unblocked, and that there are no holes or cracks in the ventilation systems. Finally, make sure that you follow manufacturer instructions when installing and using combustion appliances. Keep Firewood Outdoors Firewood often has a little mold growth on it before being brought indoors, since it contains nutrients for mold to grow and thrive. This is not a problem if kept outdoors, but the mold growth can really progress if the firewood is kept in contained areas. Shower Curtains Replace shower curtains when mold begins to become visible.

What is Relative Humidity (RH)?

Relative humidity is defined as the ratio of the water vapor pressure or water vapor content to the saturation vapor pressure or the maximum vapor content at the temperature of the air or gas. The saturation vapor pressure in the air varies with air temperature: the higher the temperature, the more water vapor it can hold. When saturated the relative humidity in the air is 100% RH. Relative humidity recommended for houses is between 30% and 50%. This level of humidity is not always easy to maintain, especially in certain “problem” areas of the home or building. A dehumidifier is often used in basements and crawlspaces where humidity can be very high. Howeve the use of the furnace may contribute to areas of your home suffering from the opposite problems: lack of humidity. Therefore, monitoring RH levels in your home will allow you to maintain areas and deal properly with seasonal variation conditions.

Examples of How Relative Humidity Changes can Occur:

On a 30 degree F day with outdoor RH of 60%, the indoor RH can drop to levels as low as 15% when the air is heated to 70F (as the air is heated it will expand giving it the capacity to hold more moisture. If moisture is not added to the air as it is heated the RH level may drop). If the outdoor temperature is 10 degrees F, the indoor relative humidity may fall to 8% or less. These are extreme levels of air dryness.  In the summer, outside air at 70F and 60% RH flows into a crawlspace at 60F causing an increase in RH up to 82%. You can see from the above examples why it is important to measure and control relative humidity levels throughout the entire home or building, since humidity levels in the air may change drastically through the heating and cooling processes. These processes can then lead to extreme highs or lows in the RH levels indoors. If you suspect unhealthy conditions in your home due to humidity being too high or too low, it is prudent to utilize a tool known as a thermo-hygrometer. This handy instrument calculates temperature and measures indoor relative humidity levels. Using a thermo-hygrometer is the best way to learn about and understand your indoor environment. This unit allows you to evaluated the RH levels in your home and understand the RH patterns, such as highs and lows, that exist. If you do have excessive humidity, and see evidence of a mold problem, then you may need an air purifier to remove mold spores from the air.

If you are experiencing any of the following symptoms, you may have been exposed to mold. The top mold health symptoms are the following in alphabetical order. A mold victim may experience one or more symptoms, separately or simultaneously:

• Allergies

• Asthma

• Bleeding Lungs

• Breathing Difficulties

• Cancer

• Central Nervous System effects

• Colds, recurring and with decreased 
resistance to infection

• Coughing and resulting sore 
lungs/chest from excessive 
coughing

• Coughing up blood

• Dandruff Problems (chronic) that do 
not go away despite use of Anti- 
dandruff Shampoos

• Dermatitis and Skin Rashes

• Diarrhea

• Eye and Vision Problems

• Fatigue (chronic, excessive or 
continued) and/or general malaise

• Feeling lost or ―disconnected from 
what is happening around you

• Flu Symptoms

• Hair Loss

• Headaches

• Hemorrhagic Pneumonitis

• Hives

• Hypersensitivity Pneumonitis 
(extrinsic allergic alveolitis, farmers 
lung disease)

• Irritability

• Itching of the nose, mouth, eyes, throat, skin or any area

• Kidney Failure


• Learning difficulties or mental functioning problems or personality changes


• Memory Loss or Memory Difficulties / Alzheimer’s-like symptoms


• Open Skin Sores and Lacerations


• Organic Dust Toxic Syndrome


• Peripheral Nervous System Effects

• Redness of the Sclera (white of youreyes)


• Runny Nose (Rhinitis), clear, thin, watery mucus from your nose may appear suddenly; or thick, green slime coming out of the nose (from sinus cavities)

• Seizures


• Sinus Congestion, Sinus Problems and Chronic Sinusitis


• Skin Redness


• Sleeping Disorders


• Sneezing


• Sneezing Fits (more than three sneezes in a row, happening often)

• Sore Throat


• Tremors (shaking)


• Verbal Dysfunction (trouble in speaking)


• Vertigo (dizziness)

• Vomiting

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