Moisture control eguide

Indoor Moisture Control

A Comprehensive eGuide

Flood Damage Pro | Water Damage Restoration | 866-869-4167 | www.flooddamagepro.com © 2005-2014 All Rights Reserved

Table of Contents

Addressing Mold: Indoor Moisture Control .................................................................................................. 2

Mold Spores in the Air .............................................................................................................................. 2

Water Sources for Mold Growth................................................................................................................... 3

Leaks and Floods ....................................................................................................................................... 3

Water in the Air......................................................................................................................................... 3

Humidity ........................................................................................................................................................ 4

What is Relative Humidity? ....................................................................................................................... 4

Measuring Humidity ................................................................................................................................. 4

Effects of Low Humidity ............................................................................................................................ 5

Effects of High Humidity ........................................................................................................................... 5

Is Condensation a Sign of High Humidity? ................................................................................................ 6

Temporary Increases in Humidity ............................................................................................................. 6

Mold and Your Health ................................................................................................................................... 7

Common Reactions to Mold ..................................................................................................................... 7

Is it Mold or Something Else? ................................................................................................................... 7

Toxic Mold ..................................................................................................................................................... 8

Treating Mold ............................................................................................................................................ 8

Controlling Indoor Moisture ......................................................................................................................... 9

Water Damage: Water Extraction and Controlled Drying ........................................................................ 9

Reducing Relative Humidity ........................................................................................................................ 10

Increase Air Temperature ....................................................................................................................... 10

Vent Appliances ...................................................................................................................................... 10

Insulate Pipes and Ductwork .................................................................................................................. 11

Use Exhaust Fans .................................................................................................................................... 11

Air Conditioning ...................................................................................................................................... 12

Keep Humidity Outside ........................................................................................................................... 12

Home Dehumidifiers ............................................................................................................................... 13

A Word from Flood Damage Pro ................................................................................................................. 14

2


Addressing Mold: Indoor Moisture Control If you see visible signs of mold on the walls or ceiling or can smell a musty, moldy odor, you may have a

mold problem in your home or business. Where there's mold, you can be certain that there is water as

well.

Any treatment to get rid of the mold must also remove the source of the water. If this is not addressed,

mold will grow there again in the future.

Mold Spores in the Air Mold is a fungus which reproduces by sending out spores into the air. Mold spores are too tiny to be

seen and are always present, both indoors and outdoors. They float on the air from place to place, just

like pollen does. When the spores encounter moisture, mold growth does not start immediately.

However, mold growth will begin within 24 to 48 hours.

Mold remediation arrests mold that is actively growing and removes it. However, it is simply impossible

to completely eliminate all mold spores from our living and working environments. For susceptible

individuals with mold allergies or asthma, this is bad news. Mold allergies and asthma are triggered by

breathing in the spores. The good news is that there are ways to minimize the amount of mold indoors.

Mold can only grow when the following conditions are met:

1. There must be moisture. Mold cannot grow without moisture.

2. Mold needs nutrients. This can be food or other organic materials, but it can just as easily be

cotton and other permeable fibers.

3. There must be a sustained moderate temperature. Typically this means between 40° F and

100° F. If it is colder or hotter, mold won't grow, and mold grows most between 70° F and 90° F

3


Water Sources for Mold Growth

Leaks and Floods Whether from a leaky pipe or from a heavy rainstorm, when water soaks your home or office, you have

to make sure the area gets dried again quickly. Water damage is an emergency that justifies an

emergency response. But what is the nature of the emergency?

It all comes down to those 24 to 48 hours, that window of time to prevent mold growth before it starts.

Once mold starts growing, mold remediation is necessary to make sure that the mold is completely

removed. Removing the moisture alone won’t kill the mold. It will merely become dormant, ready to

reactivate when it gets wet again.

In most cases, if wet or damp materials are completely dried within 24 to 48 hours after the leak or spill

occurred, mold will not grow. That's why the first response to water damage is to remove excess water,

and the second response is to employ drying equipment to speed the drying process. This drying

equipment often includes powerful air movers and dehumidifiers.

Water in the Air Remember that sticky, uncomfortable feeling from a hot, humid day? You can feel the moisture in the

air with every breath you take. People are very sensitive to humidity level as it relates to their comfort.

In fact, lower humidity is perceived as colder and higher humidity as hotter, even at the same

temperature.

Humidity is literally water in the air. High relative humidity at home or in the workplace affects more

than just our comfort. By supporting mold growth, humidity affects our health. Note that normal indoor

temperatures fall in the perfect range for mold growth, so high humidity can make mold growth

extremely likely.

4


Humidity

What is Relative Humidity? When people talk about humidity, they’re really talking about relative humidity. Relative humidity

measures the percent of water saturation in the air, based on how much water the air can hold at that

temperature. Warmer air holds more water than cooler air, which is why it is so much more common to

have really humid weather in the summertime. And relative humidity affects the rate that water

evaporates. On a hot day with low relative humidity, water will evaporate rapidly. For this reason, it is

really important on a hot day with low relative humidity to make sure you drink enough water, as you

can get dehydrated easily without realizing it.

Relative humidity in your home can increase in two ways; either the temperature stays the same and

more moisture enters the air, like taking a shower and letting the bathroom get steamed up, or the

temperature drops, and the same amount of water is now a higher relative humidity since the cooler air

can hold less water overall.

Measuring Humidity You can measure the exact relative humidity in your home with a humidity monitor called a hygrometer.

They are readily available at stores like Target and Home Depot, with a digital display that tells you the

current temperature as well as the relative humidity. These go for about $10 to $20, and you can buy

low-tech versions for even cheaper.

If you just want to know whether the indoor humidity in a particular room is too low, you can find out

with a glass of ice water. Fill the glass with water and add a few ice cubes. Wait around three minutes,

but don't move around too much in the room, as you can change the humidity level that way. Check if

water has condensed on the outside of the glass. If not, then the relative humidity in that room is too

low.

5


Effects of Low Humidity People are most comfortable with relative humidity that is between 30% and 50%. When humidity is

lower than 30%, it can impact you and your possessions negatively.

When you get shocked by static electricity in the winter, it is due to low relative humidity indoors. Low

humidity is more common in colder climates, and in the winter time.

Low humidity can cause you to have dry, itchy skin and dry eyes. Drier mucus membranes in your nose

and throat can make it more likely that you will catch a cold or other illness.

It can even affect your furnishings. Wood absorbs moisture when humidity is higher but can dry out if

humidity is too low. So hardwood floors can shrink and even crack. Wallpaper can begin to peel off as

well.

Even houseplants react to low humidity; the tips of their leaves can turn brown and dry. There is a high

tendency to over water houseplants in the wintertime when humidity is lower.

Effects of High Humidity High humidity (above 60%) can cause problems for almost all of your furnishings. High humidity can

cause mold to grow in carpets, rugs, and on upholstered furniture, as well as in permeable building

materials, like ceiling tiles and drywall.

Wood floors are particularly susceptible to moisture levels and can buckle and cup from sustained high

humidity.

Paint can begin to flake off the wall, and drywall can start to fall apart.

Moisture can condense inside air ducts, giving mold more places to grow.

Both dust mites and cockroaches thrive in high humidity, and the increased amounts of allergens they

create with their waste can trigger attacks in asthmatics and people with allergies.

6


Is Condensation a Sign of High Humidity? Condensation inside your home, whether on walls, pipes, or windows, can be a sign of high humidity.

This humidity is usually due to reduced air flow inside your home. When buildings are constructed to be

more energy efficient, the normal air flow that could reduce indoor humidity is cut off.

When water condenses inside the home, you should not only dry the wet surfaces, but you must also

locate the source of the moisture. It could be there is a leak somewhere around the window or near the

wall that should be repaired. Or you may have to take greater steps to address the higher indoor

humidity. See Reducing Relative Humidity for more information.

Temporary Increases in Humidity There are common day-to-day activities that can cause higher humidity temporarily in part of your

home.

These include:

showering

cooking

breathing

watering houseplants

But these incidences of increased humidity needn't lead to mold growth in a home where the humidity

is typically lower. Remember, mold needs humidity to be higher for a sustained period of time, 24 to 48

hours. So raising humidity temporarily is only dangerous if it is more than occasional and does not

disperse afterwards.

7


Mold and Your Health

Common Reactions to Mold Studies have found that exposure to mold can affect the health of allergic and non-allergic individuals

alike. Even in a person who is otherwise healthy, the body's reaction to mold can mimic illness in many

ways. It can seem like a bad cold, with nasal congestion and wheezing. Eye irritation and itching is also a

typical sign of mold exposure.

Like most allergies, mold exposure can also cause hives or a raised, itchy rash from direct contact of the

skin with active, growing mold colonies. The direct contact could be indoors, or even from mold in the

yard during yard work.

These minor symptoms can occur in allergic individuals and in individuals who are sensitive to molds. In

more severe cases, mold can cause fever and shortness of breath. Immunocompromised individuals can

suffer more severely from mold exposure, possibly developing a pulmonary fungal infection.

Is it Mold or Something Else? The difficulty in identifying minor reactions to mold is that many of these symptoms also occur in other

illnesses and allergies.

If the symptoms seem more allergic than viral, or last much longer than you might expect a cold to last,

it makes sense to look for these mold risk factors:

Your home has high humidity (higher than 60%) on a regular basis.

There are visible signs of mold growth on walls or furniture.

There has been water damage to the property in the past.

You smell a musty, moldy odor.

Your child is sick more often than other children.

8


Toxic Mold If you have heard of toxic black mold (Stachybotrys chartarum), and worried which type of mold is in

your home, you should know that the risk of additional health concerns from Stachybotris chartarum

and other toxigenic molds is very small and has not been definitively linked through scientific research.

The Environmental Protection Agency and the Centers for Disease Control and Prevention and do not

recommend testing the mold to see what type it is. They do, however, recommend removing any active

mold growth, regardless of the type..

There are more than 100 distinct types of mold, and any active mold growth should be addressed

promptly and removed from your living environment. Recent studies have shown a link between early

mold exposure and the development of asthma in predisposed children.

Treating Mold For small amounts of mold, you can treat it yourself, but for larger affected areas it is prudent to hire a

mold remediation specialist. A mold remediation specialist can address the moisture source that caused

the mold to grow. Until this moisture source is removed, mold can easily return in the same location.

Complete mold removal is also required. When you take away the source of moisture, mold doesn't die

but becomes dormant and can remain until there is another moisture source. So mold must be actively

removed, and permeable surfaces that cannot be completely cleaned of mold must be discarded.

For more information about mold, please see these excellent resources:

http://www.cdc.gov/mold/faqs.htm

http://www.mayoclinic.org/diseases-conditions/mold-allergy/basics/definition/con-20025806

http://www.epa.gov/mold

http://www.cdc.gov/mold/faqs.htm

http://www.mayoclinic.org/diseases-conditions/mold-allergy/basics/definition/con-20025806

http://www.epa.gov/mold

9


Controlling Indoor Moisture To control mold growth, you need to control sources of moisture indoors. The two main sources of

moisture indoors are water damage from leaks or damaged and high relative humidity. With the rapid

growth of mold in moist environments, you can’t afford to procrastinate when it comes to excess

moisture indoors.

Water Damage: Water Extraction and Controlled Drying When there has been just a small leak or a minor spill, wipe it up as best you can as soon as possible.

That way it will have a good chance of drying completely before mold can start growing.

When there is more widespread water damage, the job is a little more involved and may require special

equipment. There are two main phases in the drying process:

1. Water removal using professional water extraction equipment to remove excess sitting water

2. Controlled drying using air movers and dehumidifiers

It is easy to understand why water removal is necessary, but the reason for using drying equipment after

water removal may be less obvious. This has everything to do with the water cycle (see

http://pmm.nasa.gov/education/water-cycle for a good explanation) and how water evaporates into the

air. In a closed building with limited ventilation, when objects or surfaces dry, the water that evaporates

into the air has nowhere to go. This causes relative humidity to increase and with it the likelihood of

mold growth.

Air movers help increase ventilation to move more of the humidity from the closed structure, and

dehumidifiers remove the moisture directly from the air. Both aspects are necessary to make sure that

the area dries in time to prevent secondary damage from mold.

Since it may not be possible to adequately remove mold from permeable surfaces, preventing its growth

in the first place can save many belongings from certain disposal and may limit damage to the structure

of the property as well.

http://pmm.nasa.gov/education/water-cycle

10


Reducing Relative Humidity For health and comfort in the home, the relative humidity should be between 30% and 50%. But

everyday activities can increase the relative humidity. Some temporary increases in humidity can occur

after showering, cooking, washing dishes, and even watering plants. To return your home to its normal

humidity level, some ventilation is in order.

When humidity is more systemic, you need to look a little more closely at the possible sources for the

increased humidity. Crawl spaces, attics, and anywhere that rain and other precipitation can slip in

should be addressed. Humidity can be consistently kept lower through a combination of ventilation, air

conditioning (according to the season) and using a home dehumidifier. Be cautious in how aggressively

you lower the humidity. Indoor humidity must be carefully balanced. Just as too much is bad, too little

humidity is bad, too.

No matter which method or methods are employed, be sure to monitor the humidity closely with a

hygrometer to track the effectiveness of the measures used.

Increase Air Temperature One of the simplest ways to lower relative humidity is to increase the temperature. When the air is

warmer, the relative humidity goes down automatically, as warmer air can hold more moisture.

However, this is limited in use, as the hottest months are also the most humid, and you usually don’t

want to make it hotter.

Vent Appliances Any appliances that produce moisture in the course of their regular operation need to be vented to the

outdoors. A good example of this is the clothes dryer, which generates a lot of humidity. Most dryers are

vented to the outdoors, but keep in mind that the venting only works if the dryer vent is clear. Lint

blockages can obstruct venting of the moisture-laden air, forcing the humidity to be released into the

laundry room instead. If you find that your laundry room feels more humid than the rest of the house

during or after drying a load, then dryer vent cleaning may be required.

11


Insulate Pipes and Ductwork Some sources of moisture indoors are hidden from view behind walls, ceilings and cabinet doors. These

are the water pipes and air ducts. Even when the relative humidity is in the right range, water can

condense on cold water pipes and on air ducts. Insulating the pipes and ductwork will prevent this

condensation from occurring and causing localized damage to your property.

Use Exhaust Fans For temporary but recurring increases in humidity, there are built in solutions. Have you ever wondered

why there is a fan in the bathroom? Have you wondered how and when to use it? Many people don’t

realize that the bathroom fan was installed to remove moisture and humidity after a bath or shower.

Without ventilation, bathrooms can quickly become dank and full of mildew.

It may have its own switch, or it may come on automatically along with the light switch. According to the

Home Ventilation Institute, the fan should run both during and for at least 20 minutes after the shower

or bath is completed. Don’t be tempted to turn off the fan earlier even if the room seems back to

normal, as the full time is required to remove the water droplets from the exhaust vent ducting as well.

If you don’t have a fan, cracking the window open will help get rid of the excess moisture, but it is not as

effective. For convenience, you can even install a timer on the fan so that it will automatically turn off

after the required time has elapsed.

In the kitchen, a vented cooker hood performs much the same job as the fan in the bathroom, removing

moisture generated by cooking. In addition, the cooker hood filters the air, removing airborne grease

and odors. If you have a recirculating hood instead, it does not remove moisture from the air, so

increased ventilation from opened windows, doors, fans or air conditioning can be very helpful in the

kitchen.

http://www.hvi.org/publications/bathroom_ventilation.cfm

12


Air Conditioning In hot and humid weather, air conditioning cools indoor air as it also removes moisture. The air

conditioning unit draws indoor air in and passes it over the evaporator coils, where the air is cooled and

the water that condenses is collected and removed from the structure.

People sometimes complain that their air conditioner does not dehumidify or may even increase the

relative humidity. This is usually due to an inappropriately sized air conditioner for the space.

When an air conditioner is too powerful for the space it is supposed to cool, it will cool too rapidly. Then

it shuts off before it has an opportunity to condense the water vapor. This rapid cooling can increase the

relative humidity if it is not condensing the water before returning the air to the living space, since the

cooler air can hold less moisture than the warmer air.

Air conditioners that are too small for the space are simply too weak to remove enough moisture from

the air.

Keep Humidity Outside Especially in humid climates, vented crawl spaces can draw in more humidity than the ventilation

removes. Encapsulating the crawl space can help prevent this, but then there is the new problem of how

to depressurize the air underneath the home. A dehumidifier can be installed successfully to address the

air quality issues and reduce humidity entering the structure from the crawl space.

It also makes sense to look at the rain pathway to identify places where moisture can enter the

structure. This can be through the roof and walls, but could also be from areas around windows and

doors. If you seal these air leakage paths, you can prevent humidity from pooling in attics and wall

cavities.

Gutters should also be kept clean and in good repair, to keep rain water away from the foundation and

out of the basement.

13


Home Dehumidifiers Last but not least, running a dehumidifier can remove water directly from the air. The water is then

deposited in a collection tank which has to be emptied on a regular basis, or a hose can be connected to

the dehumidifier so that the condensed water flows directly to a drain. Many times, dehumidifiers are

used in basements, and directing the water to the drain is convenient and effortless.

A dehumidifier works very similarly to an air conditioner. It also takes in air from the room, and passes it

over evaporator coils to cool the air and condense the moisture. The dehumidifier then warms the air

again as it blows it back into the room.

Humidifiers can be used safely, as long as you follow a few simple guidelines.

Humidifiers are not recommended for use in the winter, as they can reduce the relative

humidity too much.

When using a dehumidifier, it is also beneficial to increase the ventilation to the area.

Dehumidifiers do not ventilate the air that they process. Nor do they filter it. It is simply the

same air, circulating over and over through the basement. Without introducing fresh air,

allergen levels in the air can increase and make indoor allergies worse.

Follow the manufacturer’s maintenance instructions. It may seem like a pain, but the

instructions are designed to keep the machine up and running properly, as well as reducing the

risk of bacteria and mold growth. Because the dehumidifier deals with water, bacteria or mold

that grows inside the dehumidifier could be blown into the air.

14


A Word from Flood Damage Pro

Thank you for taking the time to read our eGuide. We hope that you know a little bit more now about

the importance of monitoring and treating humidity at home. Information is powerful, and it is our goal

as a service provider to keep open and clear lines of communication in all our endeavors.

If you would like more information on moisture control or are interested in finding out about mold

remediation and water damage restoration, please feel free to give us a call. You can also find additional

information on our website, www.flooddamagepro.com.

http://www.flooddamagepro.com/

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