Why wooden fences turn green and how to fix them.

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Wooden fences are a popular choice for many homeowners because they offer privacy and can be customized to match the look of your home. However, one downside of wooden fences is that they can turn green over time. This is caused by a build-up of algae or moss on the surface of the wood. While it may not be harmful to the fence, it can be unsightly. There are a few things you can do to prevent your fence from turning green, or to remove the green build-up if it has already occurred.

In this article we will look at what is causing your fence to look green and what to do about it, as well as providing information about the best choices to prevent greening in the first place.

What causes fences to turn green

Over time, wooden fences can become discolored and even start to grow moss or algae. This is often due to a build-up of moisture, either from rainwater or humidity.

Green growth can also be caused by fertilizer run-off, which will encourage the growth of moss and algae, particularly if the fence is located near a garden. In some cases, the green discoloration is simply due to the aging of the wood.

Lets take a deeper look at each cause:

algae on fence

– Algae

Algae on a fence can appear as green, slimy patches. In some cases, the algae may also have a musty or earthy smell. If the growth is extensive, it can make the fence feel damp to the touch. In addition to discoloration, algae can also cause the wood to deteriorate more quickly.

Also note that the nutrients in fertiliser can encourage the growth of algae, mold, and mildew, thereby causing your fence to turn green.

– Mold

Mold on a fence can appear as green, black, or brown patches. It is often fuzzy or slimy in texture. Mold is dangerous because it can release spores into the air, which can cause allergies and respiratory problems.

– Mildew

While green mildew on a fence may not seem like a big deal, it’s actually a sign of a bigger problem. If the wood is allowed to stay damp, it can start to rot. This can lead to serious structural problems, and it can also create an ideal environment for mold and mildew to grow. If you have green mildew on your fence, it’s important to take steps to remove it and prevent it from coming back.

old wooden fence various colours

– Ageing of wood

As the wood breaks down, it can change color and texture, making it more susceptible to staining. Look for changes in the color of your fence, as well as any new growths or patches. If the wood is starting to flake or peel, this is another sign that it is breaking down.

Identifying the cause

There are a few ways to tell what is causing your fence to turn green. If you see green patches that are slimy or fuzzy, it is likely algae or mold. If the growth is powdery or has a musty smell, it is probably mildew. If the wood is also discolored or feels damp, it may be due to a build-up of moisture.

If you’re not sure what is causing the green growth, you can take a sample to your local nursery or garden center for identification. Once you know what is causing the problem, you can take steps to remove it and prevent it from coming back.

How to fix a green fence caused by algae, mold or mildew.

If the cause of the green fence is algae, the first step is to remove as much of the algae as possible. This can be done by scrubbing the fence with a brush or pressure washer. Once the majority of the algae has been removed, a solution of bleach and water can be used to kill any remaining algae spores. Finally, the fence should be rinsed with clean water to remove any residual bleach.

How to fix a green fence caused by ageing wood.

If the cause of the green fence is an old fence, the first step is to sand down the surface of the fence to get rid of any loose paint or wood fibers. Next, a solution of vinegar and water can be used to clean the fence and brighten its appearance. Finally, a fresh coat of paint or stain can be applied to protect the wood and give the fence a new lease on life.

1. How to clean your green fence by scrubbing with bleach

soap bucket next to fence

Supplies you will need:

-Bleach (chlorine bleach, household bleach)

-Water

-Bucket

-Pressure washer (optional for removing stubborn algae growth)

-Scrub brush

-Hose (optional)

-gloves

*If you do not have a pressure washer, you can use a hose to rinse the fence after scrubbing.

Step 1: To make the bleach solution, mix one part bleach with nine parts water.

Step 2: Pour the solution into the bucket and then dip the brush into the bucket. Scrub the fence with the brush , making sure to cover all of the algae growth.

Step 3: Allow the bleach to soak for 5 minutes or so then rinse the fence with clean water. If you are using a pressure washer, you may need to hold the nozzle further away from the fence to avoid damaging the wood.

Wear gloves when handling bleach and be sure to rinse the fence thoroughly after scrubbing to remove all residual bleach.


2. How to pressure wash your green fence

power washing fence

Supplies you will need:

-Pressure washer

-Hose

-Water

-Detergent (optional)

-Gloves

-Eye protection

Step 1: Set up the pressure washer according to the manufacturer’s instructions. If you are using a detergent, mix it with water according to the directions on the bottle.

Step 2: Hold the nozzle of the pressure washer about two feet away from the fence and start washing. Work in sections, moving the nozzle back and forth until all of the algae is removed.

Step 3: Rinse the fence with clean water after power washing to remove any residual detergent or bleach.

*Wear gloves and eye protection when using a pressure washer. Be sure to follow the manufacturer’s instructions carefully to avoid damaging the fence.


3. How to sand down and refresh an old fence with vinegar.

Supplies you’ll need:

-Sandpaper

-Bucket

-Water

-Vinegar (white)

-Sponge

-Scrub brush

-Hose

-Gloves

-Eye protection

-Mask (optional)

Step 1: Use sandpaper to sand down the fence. Start with coarse sandpaper and then move to finer grits until the fence is smooth. Use eye protection and a mask if needed to prevent dust from going in your eyes and mouth while you sand.

Step 2: Fill a bucket with water and add one cup of vinegar. If you are sensitive to the smell of vinegar the mask will help here too.

Step 3: Wet a sponge in the bucket and use it to wet down the fence. For more stubborn or affected areas use a scrub brush instead.

Step 4: Rinse the fence with clean water and allow the fence to dry completely before applying a new coat of paint or stain.


4. How to apply a sealant or stain to your wooden fence

painting after cleaning fence

After you have cleaned your fence and allowed it to dry completely, you can apply a sealant or stain to help protect the wood and prevent the growth of algae. If you are using a sealant, apply it according to the manufacturer’s instructions.

Supplies you’ll need:

-Stain or sealant

-Paintbrush or roller

-Drop cloths

-Gloves

Step 1: Choose the stain or sealant you want to use. Make sure it is compatible with the type of wood your fence is made of.

Step 2: Cover the ground around the fence with drop cloths to protect against spills.

Step 3: Put on gloves to protect your hands from the stain or sealant.

Step 4: Use a paintbrush or roller to apply the stain or sealant to the fence. Work in sections, starting at the top of the fence and working your way down.

Step 5: Allow the stain or sealant to dry completely before putting anything back against the fence or walking on the drop cloths.

Trim any vegetation around the fence that is touching the fence

Trimming any vegetation around the fence that is touching the fence will help to prevent the growth of algae and other organisms that can cause the fence to turn green. Use a pair of sharp shears or a lawn mower to trim any grass or plants that are touching the fence. Be sure to dispose of the trimmings properly so they don’t end up back against the fence.

How to prevent fences from turning green in the first place

1. Go for heat treated wooden fence panels

Wood fence panels that have been heat treated are more resistant to the growth of algae and other organisms that can cause fences to turn green. The heat treatment process kills spores and bacteria that may be present on the fence, preventing them from taking root and causing the fence to turn green.

Heat treated wood fence panels are available from most fencing companies and should be used to prevent the problem from occurring in the first place. You can identify heat treated panels by looking for a stamp that says “HT” on the panel. If you are unsure, you can always ask the fencing company or your local building code department to verify that the panels you are considering are indeed heat treated.

Heat treated panels are usually more expensive than untreated panels, but they will last longer and keep your fence looking new.

Heat treated panels are more suitable for indoor use than pressure treated because they don’t release any chemicals into the air, a downside of pressure treated panels.

2. Or Pressure treated wooden fence panels

Likewise, Pressure treated wood fence panels are also effective at reducing the growth of algae and other organisms that can cause fences to turn green.

The pressure treatment process forces chemicals into the wood, which kills spores and bacteria that may be present on the fence. This prevents them from taking root and causing the fence to turn green.

Pressure treated wood fence panels are available from most fencing companies and should be used to prevent the problem from occurring in the first place.

Pressure treated panels are usually more expensive than untreated panels, but they will last longer and keep your fence looking new.

3. Seal your fence

Sealing your fence with a quality sealant will help to reduce greening by preventing the growth of algae and other organisms that can cause the fence to turn green. The sealant creates a barrier that these organisms cannot penetrate, keeping your fence looking clean and new.

Which types of wood are least likely to turn green?

Cedar and redwood are two types of wood that are naturally resistant to rot and decay, making them ideal for outdoor use. These woods also contain oils that act as a natural repellent to insects, helping to keep your fence looking new for longer.

Cypress is another type of wood that is resistant to rot and decay, making it a good choice for fences. Cypress contains cypressene, an oil that gives the wood a natural resistance to insects and rot.

Whats the average lifespan of wooden fences?

Pressure treated wood fences can last up to 20 years, but they may start to turn green after a few years. Cedar and redwood fences can last up to 30 years, but they may also start to turn green after a few years.

The lifespan of your fence will depend on the type of wood you choose, the climate you live in, and how well you maintain your fence.

Alternative materials to wood fences

white composite fence

Wood is a popular choice for fences, but it is not the only option.

There are many other materials that can be used to create a fence, and each has its own advantages and disadvantages.

One material that you may want to consider is composite. Composite fences are made from a mixture of wood and plastic, and they are very durable. They are also low maintenance and won’t rot or decay like wood fences can.

Another material that you may want to consider is aluminum. Aluminum fences are lightweight and low-maintenance, and they will not rust or corrode.

Conclusion

Fences turn green when algae and other organisms grow on the surface of the wood. This can happen because the wood is not sealed or because the fence is located in a humid environment.

To prevent your fence from turning green, you should seal it with a quality sealant and choose a type of wood that is resistant to rot and decay.

If your fence does turn green, you can clean it with a power washer or a bleach solution. You may also want to consider repainting or staining your fence to help protect it from the elements.

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