5 Tips from the Experts on Crawl Space Mold Prevention
Crawl spaces are notorious for growing mold. Is crawl space mold prevention possible? What steps can you take to prevent major damage from occurring to your home? If you do find mold, do you know what to do next? We answer all your questions and more!
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Why Are Crawl Spaces Prone To Mold Growth?
Before we talk about mold prevention, let’s talk about crawl spaces are so prone to mold growth. After all, you have to know your enemy before you can fight it.
Reason 1 – Dry Inside, Wet Outside
Generally, the dirt in a crawl space (under your home) is drier than the dirt around the foundation. This results in moisture wicking into the crawl space from the dirt outside. Once inside the crawl space, the moisture evaporates into the air and the water vapor moves up and settles on ductwork, floor joists, subfloor, and/or floor insulation.
During the summer, the air and surfaces inside a crawl space are generally cooler than the outdoor air. As warm, humid air moves into a crawl space through the foundation vents, it begins to cool, resulting in an increase in relative humidity. Condensation from water vapor gathers on the ductwork, floor joists, subfloor, and/or floor insulation.
Reason 2 – ‘Sweating Pipes and Ducts’
Crawlspaces are places where water pipes, air conditioning vents, duct work, and other functional parts of the house are located. The pipes, vents, and ducts frequently ‘sweat’ or have excess moisture associated with them, especially in the summer. The temperature inside the pipe or duct is much cooler than the surrounding air and moisture is attracted to the cool surface.
Think about it like this…picture a glass with ice water. The ice inside the class melts, decreasing the temperature of the water. Moisture from the surrounding air condenses on the glass making the glass ‘sweat.’
Pipes and ducts are very similar. The temperature inside the pipe or duct is much cooler than the surrounding air, and moisture is attracted to the cool surface. Therefore, the pipes, vents, and ducts frequently ‘sweat’ or have excess moisture associated with them, especially in the summer. Excess moisture is always a problem, because excess moisture leads to mold growth.
Reason 3 – Leaks
Leaks are another a frequent cause of mold growth. The crawl space is an area of your home that is rarely visited. When was the last time you went down there? It’s not the most pleasant place to visit. Leaks are a preventable problem in a crawlspace. Tiny drips can cause even more problems than gushing water if left unchecked. Simply checking all the pipes 4 times a year can prevent many problems.
Reason 4 – Inadequate Ventilation
Although most crawl spaces are vented, they are still passive systems, meaning that ventilation only occurs due to pressure changes and wind that happens to blow through the vents. Few crawl spaces have powered ventilation systems, which can create their own problems. Limited ventilation results in an accumulation of stagnant air. In this environment, mold, radon, and moisture (which attracts termites and rodents) can build to dangerous levels.
Warm air inside a home rises and escapes through the attic, drawing in cooler air from lower levels, including outdoor air and air from the crawl space. Running exhaust fans in the kitchen and bathrooms creates a negative pressure inside the home. This negative pressure also draws in air from outside the home and from the crawl space.
Reason 5 – Leaks in Your HVAC System
HVAC systems are frequently located in the crawl space. Most HVAC systems, even many new systems, have some leaks around the air filter, between individual sections of ductwork and at the duct boots. These leaks reduce system efficiency and allow dirty crawl space air into the system and your home.
We’ve discovered many problems with customer’s HVAC systems including:
- disconnected supply and return ducts
- loose and leaking joints between sections of ductwork
- missing air filters and covers
- unsealed ductwork
- holes chewed into flex ducts by rodents
- seen rodents—dead and alive—inside ductwork
In a particularly bad situation, air filters are located inside the floor or walls inside the home, and there is a leak in the return ducts. In this case, airflow is slightly restricted by the filters. Like water, air will take the path of least resistance. Unfiltered air from the crawl space will be drawn directly into the return ducts. This dirty air is then heated or cooled, and blown directly back into the living space through the supply ducts.
Although your crawl space is not part of the living space of your home, you should think of it as an extension of the breathing space of your home when it comes to indoor air quality. Like it or not, you are breathing air from your crawl space.
To learn more check out our post: HVAC System in Your Crawl Space? You May Be Breathing Dirty Air.
How Does Mold Grow?
Molds grow from microscopic spores that are universal. You can find molds on every continent, and in almost every type of environment. Mold needs 4 things to grow: oxygen, moisture, a food source, and warmth. The most unusual thing about mold is that molds grow inside of their food sources. They can penetrate deeply into drywall, carpets, underneath kitchen and bathroom sinks, etc. Mold is going to live in your crawlspace. However, there is something you can do to stop it from growing. Keep reading to find out!
Symptoms Of Mold In Your Crawl Space
How do you know if you have mold in your crawl space? Musty smells (think wet dog, old gym sock type smells) in your home or coming from your crawl space may be the first clue you have a mold problem.
Mold grows because of excess moisture. Anything that causes excess moisture in your crawl space can cause mold to grow such as:
- condensation on air conditioning ductwork or water pipes
- leaking pipes
- moisture damage
- high humidity in the living area
- buckled hardwood floors
- insect infestations
- rot of floor timbers
Is Crawl Space Mold A Health Problem?
In one word… Yes. Mold is an insidious, invisible predator in your home. It hides in places no one ever thinks to look like under cabinets, in crawl spaces, and behind furniture. People may spend weeks, months, and even years fighting illness, and never know what they are really fighting…mold. Many of our customers find us after a recommendation from their doctor, that they may in fact have a mold problem, and not just an illness.
Mold is most often associated with allergies, but mold is much more menacing than people know. While all molds have the potential to cause irritation and allergy symptoms, molds can also cause much more dangerous health problems including: fungal poisoning and mental health problems.
You can learn more about mycotoxin poisoning in our article: When Mold Is Worse Than Allergies.
To learn more about how mold can affect mental health check out our articles: Mold and Mycotoxins: Effects on the Brain and Nervous System in Adults and Effects of Mold on Children’s Health.
Crawl Space Mold Prevention Tips
At last we are going to get into the meat of this article, and talk about prevention. It’s important to know your enemy (mold) before you can prevent it from causing problems. The best way to prevent mold growth is by preventing excess moisture from entering your home. Check out our top tips for crawl space mold prevention.
Tip 1 – Start at the Top – Check Your Gutters
It may seem counterintuitive to start at the top of your home when you’re trying to prevent water damage to the bottom. However, gutters and downspouts are very important in routing water away from your home and foundation. Water must be routed away from the foundation of your home so that you can prevent numerous problems including: foundation and structural damage, water damage, and of course mold.
A home without gutters is just asking for water damage and foundation issues. Clogged gutters are just as bad and don’t help funnel water away from the foundation.
Clean gutters (or have a professional clean your gutters) at least twice a year to prevent clogs. Downspouts should carry water at least 2 feet or more away from the home, and have a 90 degree angle elbow at the ground level. 10 This prevents soil from washing at the foundation level, and helps prevent foundation damage. 10
Downspout extensions can help to move the water further away from the foundation. 10,16 This is a DIY project and can easily be done for all downspouts in a few hours. Click on the link for a great video on ‘How to Use Downspout Extenders to Protect Your Foundation.’
Tip 2 – Check your Water Pressure
High water pressure can make your home more prone to leaks. If the water pressure in your home is too high, it can put a strain on pipes, hoses, gaskets, and more. To check the water pressure in your home, you can purchase a water pressure gauge, and attach it to an outside faucet to check the pressure. Turn the water on full force and check the measurement. You may need to attach a pressure regulator to the water line as it enters the home if the pressure is too high.
To learn more go to: How to Test Your Home’s Water Pressure.
Tip 3 – Check for Leaks 3-4 Times per Year
Cracks in pipes, hoses, and clogs in drains can become a nightmare if forgotten long enough. Check pipes in the crawl space, under sinks, around toilets and showers, and near appliances at least every 3-4 months. Areas under sinks, behind appliances, around toilets, and baths or showers should stay dry to prevent mold growth.
Use strainers on all sink drains to help prevent clogs from hair or food buildup. If a clogged pipe develops, fix it quickly! Don’t wait weeks or months to solve the problem of a slow draining sink. The longer you wait… the longer the mold has time to grow.
For more about how to keep drains healthy and flowing go to: How to Prevent Water Damage to Your Home.
Tip 4 – Check your Water Heater
Corrosion can cause traditional water heaters to leak over time. Avoid problems with repairs and plan a replacement date (about every 10 years) for your tank type water heater.
One way to avoid this type of water damage is with tankless water heaters. According to Energy.gov tankless water heaters “can be 24%–34% more energy efficient than conventional storage tank water heaters.” Tankless water heaters can be more expensive initially, but save energy and typically last longer than tank type water heaters.
To learn more about tankless water heaters go to Energy.gov, How to Select the Right Size Tankless Water Heater, and Read This Before You Buy a Tankless Water Heater.
Our top pick for a tankless water heater –Rinnai RL75IN, Large, Natural Gas Tankless Hot Water Heater.
Tip 5 – Check Your HVAC System For Leaks
A leak in the supply or return lines can suck dirty air into the ducts, and blow it directly into your home. On several occasions, we have performed mold inspections where the only real problem was that the HVAC system was sucking in unfiltered air.
Improperly sealed and leaking returns and supplies are more common in older homes, but newer homes are not immune to these problems. Be sure to check your HVAC system when you are checking for leaking pipes as part of your routine home maintenance schedule.
Check out our post How to Seal Floor Vents for a great DIY video.
What Do I Do if I Find Mold?
Now that you have checked all those little seen places, what should you do if you find mold? Customers often ask us, “Can I clean the mold myself or do I need a professional?” Our answer depends several factors including:
- how extensive the mold problem is
- what building materials, furnishings, and belongings are affected
- where the mold is located
- whether or not you mind being in confined spaces such as your crawlspace, basement, or attic
If you’re familiar with our blog, you know that the first thing to do when cleaning mold is to fix the moisture problem that led to the mold growth. Until you fix the moisture problem, mold will continue to grow and spread.
Mold is great at hiding in hard to detect locations such as in drywall and insulation. There is a good chance the mold problem is more than an isolated issue, if the area of mold covers more than about 10 square feet. If you smell a musty odor in your home you can’t identify, or have health problems associated with mold, it’s time to call in the professionals.
To get all the details check out our post: Cleaning Mold: DIY vs. Professional.
Especially if you don’t live in our service area, you should check out our post: How to Choose a Mold Removal Company. We answer every question you should ask a mold removal company, and give you the details you need to know.
The Branch Difference
If you think you’ve got a real problem, you’re far better off with a thorough inspection like ours. At Branch Environmental, we analyze the symptoms to determine the root cause of your problem. We see each mold inspection as an in-depth investigation, not an opportunity to hand over a guess-based estimate of work. If you think you may need a crawl space mold inspection, get in touch with us, and we’ll get down to the source.
Call Branch Environmental. We’re experts not only at mold removal, but at determining and remediating the underlying causes. From hidden mold sources to major contaminants, we can identify exactly what is going on in your home and rid it of environmental toxins, often for good.
Branch Environmental – Because nobody should live or work in a building that makes them sick.
For more information go to:
- How to Prevent Water Damage to Your Home – The Spruce
- How to Prevent Bathroom Mold – Branch Environmental
- Do You Have Mold? How to Choose Between a Paid or Free Mold Inspection – Branch Environmental
- What’s that musty smell? MVOC’s – Branch Environmental
- Is mold damage covered by homeowners insurance? – Insurance.com
- How Does Mold Affect Your Health? – Branch Environmental
- How Your Home Can Affect Your Allergies – Branch Environmental
- When Mold Is Worse Than Allergies – Branch Environmental
- Mold and Mycotoxins: Effects on the Brain and Nervous System in Adults – Branch Environmental
- Effects of Mold on Children’s Health – Branch Environmental
- HVAC System in Your Crawl Space? You May Be Breathing Dirty Air – Branch Environmental
- Top 10 Ways to Prevent Water Damage – Branch Environmental
- Home Mold Remediation – Branch Environmental
- How to Choose a Mold Removal Company – Important Facts That You Should Know – Branch Environmental
- How Your Crawl Space Impacts Indoor Air Quality – Branch Environmental
- $75 Crawlspace Special and Why It’s NOT a Bargain – Branch Environmental
- How to Seal Floor Vents – Branch Environmental
- 6 Ways to Prevent a Wet Crawl Space – Branch Environmental
- Mold vs. Mildew – Branch Environmental
- What’s that musty smell? MVOC’s – Branch Environmental
- Cost of Mold Removal – 5 Important Facts You Should Know – Branch Environmental
- How to Use Downspout Extenders to Protect Your Foundation – Ron Hazelton
- Top 6 Types of Water Damage – Branch Environmental
- Spotlight on Mold Removal – Branch Environmental
- 10 Tips To Avoid Water Damage to Your Home – McClain Insurance
- How to Test Your Home’s Water Pressure – The Spruce