Is Deck Mold Dangerous?

If you’re in the process of repairing or replacing an old deck, you may have encountered sections of rotten wood that are infested with deck mold. Although unpleasant to deal with, it’s not uncommon for decks to slowly grow mold, especially if you live in a region with persistent rainfall or humidity. Yet many homeowners balk at the discovery and worry whether it’s dangerous to handle moldy wood.

A variety of molds and fungi can grow on a deck that’s exposed to regular moisture but one strain, in particular, can cause serious health problems—Stachybotrys chartarum, AKA black mold. Even if the mold does not contain Stachybotrys chartarum strains, leaving it to rot will damage the wood and can lead to personal injury if the boards break underfoot. 

Before continuing to work on your deck, take a moment to read more about deck mold and how it can affect your health and safety. If your deck is infested with mold, we recommend using caution while removing and replacing the boards and will guide you on how to prevent similar issues in the future.

How to Identify Deck Mold?

Before we get into the details, take a moment to verify whether your deck is infested with mold or simply has a mildew problem:

  • Mold: Mold is a type of fungi that breaks down dead organic matter, such as leaves or wood. It’s often found in areas with high humidity or moisture, such as bathrooms, basements, or kitchens. Mold is usually black, green, or white and can appear fuzzy or slimy.
  • Mildew: Mildew, on the other hand, is a type of fungus that only grows on the surface of organic matter. It’s often found in damp areas, such as shower stalls or laundry rooms. Mildew is usually white or gray and has a powdery texture.

If you’re unsure whether your deck has mold or mildew, simply pour a small amount of bleach onto the affected area. If the wood lightens in color, it’s mildew; if the color remains the same, it’s mold.

Read: How Much Does A 14×20 Deck Cost To Build On The Backyard?

Are all Molds Dangerous?

There’s a general assumption that all molds are dangerous and will lead to health problems but this isn’t necessarily true. For example, penicillin—one of the most common antibiotics—is made from penicillium mold, and, without it, many common illnesses would go untreated. However, the danger lies in not knowing what type of mold has infested your deck.

There are more than 100,000 types of mold, many of which can cause illness. If your deck has become overrun with mold, there’s no telling whether it’s infested with a benign or noxious strain so it’s best to err on the safe side.

For example, one of the most common molds to infest households is Stachybotrys chartarum, or the dreaded black mold. Black mold is particularly bad for your health and can cause a host of respiratory problems, such as coughing, wheezing, and watery eyes. In severe cases, it can lead to memory loss, depression, or even death.

If you suspect that your deck has been infested with black mold, you should take immediate action to remove it. However, we recommend calling a professional to do the job if you are unsure how to protect yourself, as black mold can be difficult to remove and is particularly dangerous to handle.

Read: How To Get Rid Of Raccoons Under Deck?

Safety Measures to Take Before Handling Moldy Wood

If you’ve determined that your deck has a mold problem, you need to take precautions to avoid becoming sick. The first step is to purchase an N-95 respirator, which will protect you from inhaling mold spores. You can buy a respirator at most hardware stores or online.

In addition to wearing a respirator, you should also take the following steps:

  1. Wear long sleeves, long pants, and gloves to avoid coming into direct contact with the mold.
  2. Soak the affected area with a bleach solution (1 part bleach to 3 parts water) to kill the mold.
  3. Scrub the area with a stiff brush to remove any remaining mold spores.
  4. Rinse the area with clean water and allow it to dry completely.

After taking these precautions, you should be safe to handle the moldy wood. If you are still unsure about how to proceed, we recommend calling a professional to remove the mold for you.

Read: How Often Should You Stain Your Deck?

How to Prevent Mold Infestations in the Future?

Modern decking materials are designed to be mold-resistant and are usually coated with chemicals that prevent mold and mildew from growing. However, even the most mold-resistant decking material will eventually succumb to mold if it’s not properly cared for.

To prevent mold from growing on your deck in the future, we recommend taking the following steps:

  • Clean your deck regularly with soap and water to remove dirt, debris, and leaves. Fallen debris creates the perfect conditions for mold to grow in so, by keeping your deck cleared, you can avoid potential infestations
  • Inspect your deck regularly for signs of mold or mildew and treat affected areas immediately using bleach or an anti-fungal chemical treatment.
  • Repair any cracks or damage to the deck to prevent moisture from seeping in and make sure that your deck has proper drainage to avoid puddling water.
  • Keep trees and bushes trimmed so they don’t shade the deck and trap moisture or drop leaves and debris onto the wood.
  • Cover your deck when not in use to protect it from the elements.

By taking these steps, you can prevent mold from growing on your deck and keep it looking its best for years to come. If you live in a particularly damp region of the country, we highly recommend investing in a deck cover to prevent moisture from unnecessarily seeping into the wood.

Read: What Are Composite Decking Pros And Cons?

The Takeaway

Although deck mold is unsightly and can cause respiratory problems, it’s not necessarily dangerous to handle. However, we recommend taking precautions to avoid coming into contact with mold spores. In addition, it’s important to identify the type of mold growing on your deck so you can take the necessary steps to remove it and prevent it from coming back.

Read: Why Retaining Walls Collapse?