Will Bleach Stop Wood Rot? — Wet and Dry Treatment

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If you notice wood rot in a workpiece or surface, chances are it can lead to structural damage and costly repairs. Because of this, many homeowners are eager to find ways to stop the decaying process at all costs. 

Among the available preventive measures, will bleach stop wood rot or not? Here are some insights into this widely debated topic.

3 Different Types of Wood Rot and Their Causes

Before I discuss the steps in treating wood rot, here are all the rot fungi types you’ll encounter on decayed wood. You must know the difference between them to determine the proper method of preventing wood rot. 

1. Brown Rot

Although most woodworkers call it “brown” rot, this type of wood-destroying fungus comes in slightly different color tones. These rot stains can make the wood soft, resulting in the structure’s crumbling and breaking.     

wood brown rot

If you don’t prevent wood rot, it will slowly turn the material’s parts into powder until it’s not strong enough to hold against weight and pressure.       

2. Dry Rot

Dry rot is a decaying process that stems from brown or white rots. The wood surface must have 20% excess moisture before these fungus spores can spread in the material. 

Even if the affected wood dries, this destructive fungi can take the rot damage further. 

What Does it Look Like and What are the Causes?

You can identify an early case of dry rot if you sight traces of white cotton-like wool on the wood surface. 

If you let the fungus spores germinate and spread further, the wood structures will likely develop small square-shaped cracks. 

deck water damage

After that, the dry wood rot will turn into a mushroom-like form. It indicates that the decay has consumed all the fresh wood and will crumble at any moment. 

Treating Dry Rot

You must remove the rotted wood parts to prevent rot from developing further. I also suggest cutting away portions of the sound wood, especially if they exhibit visible signs of decay [1]

It’s wise to remove rot stains since they could escalate to fungal growth. Stopping wood rot also entails removing the mushroom-like fungus. Once they’re out, you can use a stiff brush to treat wood and its surroundings from surface growth.  

In addition to the aforementioned approaches, wood rot can also be addressed by utilizing readily available fungicide products found in today’s market. These fungicides are specifically designed to combat and prevent the growth of fungi that cause wood decay.

3. Wet Rot or White Rot

Wet rot requires at least 50% moisture before spreading and manifesting over your wooden workpiece. Regardless of where these water leaks are coming from, the fungi will continue to consume the lignin, leaving you with rotten wood. 

rotting wood due to water damage

What Does it Look Like?

It’s easy to spot this wood rot because it darkens the affected area. Since the wood soaks with moisture, it’ll show a soft texture with brittle breakages. 

Most rotted wood pieces with this fungi also have a rising damp and musty smell. 

Treating Wet Rot

I highly recommend assessing the moisture source and the material’s current condition first to determine how to prevent wood rot from spreading. 

Don’t forget to scrape the decayed parts away before applying wood rot treatments over the surface. 

Ensure that the wood is dry before adding another coat of treatment. It will also help if you apply fungicide on surrounding surfaces to avoid material decay in the long run. 

How Bleach Works to Stop Wood Rot

When repairing impermeable surfaces, you can stop recurring wood rot with bleach. You may not know, but bleach kills mold and mildew with oxidizer components. 


Chlorine bleach produces chemical reactions that block enzymes from spreading and reproducing. 

Why is My Bleach Solution Not Working?

Although you can apply bleach on rotted wood, it’s only effective on the material’s surface level. 

No matter how much bleach you add, this treatment won’t penetrate the board. If the rotting persists after its application, I recommend exploring alternative methods.

5 Easy Steps to Stop Wood Rot with Bleach — Here’s How!

Tools & Materials You’ll Need

Step #1: Know the Main Source of the Moisture

The moisture could come from washing machine leaks or damaged plumbing, so it’s worth checking these typical sources. 

moist deck

Besides the laundry room, water damage can also stem from leaking windows and other exposed house parts. 

After identifying the source, wear protective gloves and start repairing the leaks. You should also run a humidifier to dry out the moisture in the affected area. 

Step #2: Prepare Your Wood for Bleaching

If the wood sections are rotten to the core, it’s time to replace them with pre-treated boards. Meanwhile, you can salvage repairable pieces by carving the decayed parts with a chisel and brush. 

Step #3: Start Applying the Bleach to the Affected Area

Next, you must dilute chlorine bleach in a clean container. After a while, soak a cotton cloth in the diluted chlorine bleach. 

neutralizing bleach with vinegar

You can apply the solution and rinse the excess bleach with lukewarm water before letting the surface dry. 

Step #4: Applying the Wood Filler (to the Holes/Cracks) and the Finishing Coat

After drying the wood, you must fill the gaps from fungus extraction. You can use polyester or epoxy wood filler for this step. It’s okay to apply generously since fillers often shrink after they dry. 

Step #5: Maintain Your Wood in Ideal Condition

Removing rotten wood sections isn’t the end of the process, especially because you must maintain the workpiece to prevent decay formation. 

If you live in a humid area, you must install ventilation or a humidifier to keep the surface dry.

Suggested: Will an Outdoor Rag Damage a Wood Deck?

Alternatives to Stop Wood Rot

Boric Acid (or Borate)

You can use boric acid as a wood hardener to prevent the decaying process from escalating to the surface. Borate solutions also protect materials from potential rotting in the long run. 

treating wood with boric acid

Ethylene Glycol

Although it’s a toxic material, Ethylene Glycol can penetrate wood fibers and eliminate fungus. It sticks to the surface and prevents rotting recurrence. 

Treating Wood to Prevent Rot: 6 Tips and Tricks

Tip #1: Apply Wood Preservatives

These don’t block moisture, but they can stand against decay and rot. 

Tip #2: Use Decay-Resistant Wood Types

I recommend opting for wood species that have a strong resistance to rot, such as oak or redwood.

Tip #3: Refrain from Installing Your Wood Deep in the Ground

A deeper ground installation can expose the material to more moisture, so the depth shouldn’t exceed 15 inches. 

Tip #4: Use a Dehumidifier

Maintain the dryness in the area with a dehumidifier, reducing the chances of moisture developing. 

dehumidifier power and control buttons

Tip #5: Keep Downspouts & Gutters Away from Outside Wood

You must ensure outdoor wood pieces are away from gutters or outlets where water often gathers.

Tip #6: Consider Installing Good Ventilation in High-Moisture Areas

Highly humid areas like bathrooms and washrooms must have air vents and exhaust fans for cooler and drier airflow. 


How can You treat wood rot fungus?

You must identify and fix the moisture source. After that, remove the rotting wood from the affected area and kill the remaining decay with bleach.

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Whether bleach will stop wood rot or not highly depends on the material’s current condition. More crucially, I advise acting promptly at the first signs of decay, no matter how small. After all, you wouldn’t want to turn this repair job into a costly board replacement task.

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Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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