How to Remove Mildew from Stained Decks

Mildew on a stained deck is more than just an eyesore; it can compromise the structural integrity of your wood over time. Fortunately, with the right approach and cleaning products, you can effectively remove mildew and restore your deck's beauty. This comprehensive guide will walk you through the process, answering common questions along the way.

What Causes Mildew on Stained Decks?

Mildew thrives in damp, shady environments. Your stained deck is particularly vulnerable if it's located in a humid climate, receives limited sunlight, or isn't properly maintained. Standing water, poor drainage, and infrequent cleaning all contribute to the growth of mildew, a type of fungus that feeds on organic matter within the wood's surface. Understanding these factors is the first step in preventing future infestations.

How to Identify Mildew on Your Deck

Before you start cleaning, it's crucial to properly identify mildew. Mildew typically presents as a dark, fuzzy growth, often black, green, or gray in color. It can appear as spots or spread across larger areas. Don't confuse mildew with discoloration from age or weathering; mildew is a living organism, unlike simple staining. If you're unsure, a small test area can help confirm whether it's mildew or simply dirt.

What's the Best Way to Clean Mildew Off a Stained Deck?

The best approach involves a two-pronged attack: cleaning and prevention. Let's break down the cleaning process:

1. Preparation is Key:

• Safety First: Wear protective gear, including gloves, eye protection, and a respirator, especially when using chemical cleaners.
• Clear the Deck: Remove all furniture, plants, and debris from the deck's surface to allow for thorough cleaning.
• Pre-wetting: Use a garden hose to thoroughly wet the deck. This helps to soften the mildew and prevents the cleaning solution from drying too quickly.

2. Choose Your Cleaning Solution:

Several options exist, ranging from natural remedies to commercial cleaners:

• Oxygen Bleach: A safer and environmentally friendly option, oxygen bleach is effective against mildew without harsh chemicals. Follow the product instructions carefully, typically involving mixing it with water and applying it with a scrub brush.
• Commercial Deck Cleaners: Many commercial deck cleaners specifically target mildew and algae. Read the product label carefully to ensure it's suitable for your stained wood. Always test a small inconspicuous area first to check for any color fading or damage.
• DIY Solution (for mild mildew): A mixture of water and white vinegar (roughly a 1:1 ratio) can be effective for light mildew infestations. Apply, scrub, and rinse thoroughly.

3. Scrubbing and Rinsing:

• Scrubbing: Use a stiff-bristled brush to scrub the deck thoroughly, paying special attention to areas with heavy mildew growth. A deck brush with a long handle can make this task easier on your back.
• Rinsing: Rinse the deck thoroughly with a garden hose to remove all traces of the cleaning solution and mildew. Ensure that all cleaner residue is removed to prevent staining or further damage.

4. Drying:

Allow the deck to air dry completely before applying any sealants or stains. Sunlight will help accelerate the drying process.

How Often Should I Clean My Stained Deck?

The frequency of cleaning depends on factors such as climate, shade, and usage. At a minimum, inspect your deck at least twice a year (spring and fall) for signs of mildew. In humid climates or heavily shaded areas, more frequent cleaning might be necessary.

Can I Prevent Mildew from Growing Back on My Stained Deck?

Prevention is key to maintaining a mildew-free deck. Here are some essential strategies:

• Regular Cleaning: Regular cleaning, as discussed above, prevents mildew from establishing a foothold.
• Proper Drainage: Ensure that water drains away from the deck efficiently. Consider adding grading or drainage systems if necessary.
• Sunlight: Trim overhanging branches to allow more sunlight to reach the deck, inhibiting mildew growth.
• Sealing: Applying a high-quality wood sealant helps protect the wood from moisture, making it less susceptible to mildew.

What if the Mildew is Extremely Persistent?

For stubborn mildew infestations that don't respond to standard cleaning methods, consider consulting a professional deck cleaning service. They have access to stronger cleaning agents and specialized equipment that can effectively remove even the most tenacious mildew.

By following these steps and implementing preventative measures, you can effectively remove mildew from your stained deck and keep it looking its best for years to come. Remember to always prioritize safety and follow the instructions on any cleaning products you use.