Step-By-Step: Protect Your Fence Posts from Rotting


Fence posts can withstand rain, snow, wind, and other things, but only for so long if they are not protected.

After some time, the wooden fence posts soak in the water from rain or from the soil, and if the post does not dry out, it will rot.

Whether you are building a new fence or you want to treat your current fence as a precaution, this step-by-step list will help you keep your fence posts from rotting!

Step One: Pick the Best Wood for Your Fence

There are many different types of wood out there. Some are better for fences than others. For example, pine and cedar are most often used when building fences.

When planning your fence, you want to pick the best kind for the best price. Since there are many options, it is important to do your research to find which fence post material will work best for you and your fence.

Here are some of the options that you have:

  • Rot-resistant woods
  • Pressure-treated wood
  • Fresh wood

Rot-resistant Wood

There are some types of wood that are naturally moisture repellent. Cedar, redwood, and mulberry strains are great types of wood that do not soak up a lot of moisture.

They are more expensive, but for some, they may be worth it, since they fight back against the signs of decay. In the long run, you will probably have to replace your fence less often and have to do less maintenance.

Pressure-treated wood

If rot-resistant wood is too expensive for your taste, you should try pressure-treated wood.

This type of wood is infused with preservatives to keep the wood from rotting or being destroyed by insects.

Pressure-treated wood is less expensive than rot-resistant wood but works just as well. You can find it at any home improvement store and it will usually have a green tint to it.

For wood to be pressure-treated, it has to go through a special process.

  1. The wood is placed in a pressurized tank where the air in the wood is removed.
  2. Preservatives are sprayed to fill where the air used to be in the wood.
  3. The pressure chamber is drained, allowing the wood to start to dry.
  4. The pressure-treated wood dries for 24-48 hours.

The pressurizing process helps the wood become safe from water and insects. With pressure-treated wood, your fence will be, for the most part, safe from any weather and rot.

It is a good idea to use either pressure-treated wood or rot-resistant wood for a fence.

Fresh Wood

Fresh wood is wood that has just recently been chopped down.

Maybe you wanted to use your own wood from a tree in your backyard, a friend had extra wood lying around, or you like the idea of fresh wood for your fence.

Whatever the reasoning is, you can use fresh wood for your fence posts, if you take the proper precautions.

The most important thing to do when you are using wood is to make sure that the wood is completely dry before using it as a fence post.

The drying process could take several months if you decide to use fresh wood, so keep that in the back of your head when choosing which fencing materials you want for your fence posts.

Rot thrives when the wood is wet and moist. Wood has a hard time absorbing preservatives, so it is important to use dry wood for your fence post.

If you decide to use fresh wood, it is important to treat it with preservatives before using it for your fence post. A common preservative is Cuprinol.

When treating your own wood, make sure that you are in a place with great ventilation or outside. The chemicals in the preservative can be toxic if inhaled.

Next, you need to measure what piece of wood is going to be in the ground. This is the part that you want to treat.

Take a paintbrush and brush on the preservative in layers. You will want to apply the coat every hour until the wood stops absorbing the preservative.

Once the wood does not absorb any more preservatives, the fence post is protected from moisture and pests.

This option is time consuming and not used frequently, but if you have the time and means, as well as the know-how, it definitely can work.

Step Two: Dig the Hole for the Fence Post

Now that you have chosen your fence post material, you are ready to build your fence.

When you are digging your fence post hole, you need to make sure the hole is 1/3rd as deep as the post so the post will be sturdy enough to hold the fence.

So, if your fence post is 6 feet tall, you should dig a hole about 2 feet deep.

The diameter of the hole should be three times as wide as the post so there is room to pour gravel and concrete.

When digging the hole, you can use a shovel or a fence post driver. The process is up to you and your preferences.

It can be tough work but it is important to make sure you dig far enough down and wide enough for a sturdy fence.

Step Three: Pour 6 Inches of Gravel into the Hole

After you dig the hole, you will want to fill the hole with 6 inches of gravel. Gravel is a great barrier from the soil because it will act as a funnel so water will not sit in the hole.

It also protects the fence post from the moisture of the soil, so the wood will remain dry and safe from rotting.

Gravel works best when you have heavier soils, so if you have loose, sandy soil, you may want to try something different. Any type of gravel will work.

Step Four: Insert the Post into the Hole

After you have put the gravel in the fence post hole, you are ready to insert the fence post.

Before doing this, make sure the wood is completely dry and that it has been treated properly or that it is rot-resistant wood.

If it is not, the wood could rot, even if you use gravel.

Make sure you insert it straight and deep enough for the length of your post.

Step Five: Fill the Rest of the Hole with Concrete

Adding concrete creates another layer to protect your fence post from water and pests.

After the fence post is in place, add the cement to the rest of the hole. You will need another person to either hold on to the fence post to keep it steady or to pour the cement into the hole.

The concrete should be two to three inches above the soil level and angled away from the post, so water flows away from the wood post.

Since the concrete is above the ground just a few inches, it keeps the water from finding a way to the fence post, which keeps the wood dry and safe from rot.

By creating an angled effect with the cement, the water will flow into the grass or soil, rather than sitting in a pool by the fence post, keeping the wood as dry as possible.

Step Six: Caulk around the Fence Post Base

Now that the fence post is anchored into the ground, you will want to make sure there is no room for any water to seep down and allow for the wood to rot.

Once the cement is dry, you will want to take exterior caulking and create a seal around the fence post base. Use either exterior acrylic latex caulk or silicone caulk because they will stick to the concrete.

Caulking the fence post will create the final seal that will protect your fence from rot and pests.

Step Seven: Stain the Fence

After your fence post is sturdy and ready to go, it is wise to stain the post.

Not only does it make the fence look better, but it also acts as another layer of protection from the weather and any pests.

You have done all of the steps to protect the part of the fence post that goes in the ground. Staining the fence helps protect the top part of the fence from weathering and rot.

There are many ways to stain a fence. One way is to paint on the stain with a brush or a roller. This usually takes longer.

You can also use an airless sprayer, which is a much faster way to stain wood.

Keep in mind that it typically takes two coats to stain a fence, but that is up to personal preference and style.

You can also use paint instead of stain. There’s some debate as to what is best. You can read our article on whether to stain or paint here.

Step Eight: Clean the Fence Regularly

Preparing your fence post when building your fence is important, but keeping your fence post clean is just as important.

Fences are constantly faced with the weather, sunshine, mud, bugs, and anything else that is outside. If the fence gets dirty and is not cleaned, it can easily start to grow bacteria and fungi, which will rot your fence posts.

An easy way to keep your fence clean is to power wash it occasionally.

Just like your house, your fence needs to be cleaned as well.

You could power wash your fence when you power wash your house, or you could do it more often. It is up to you!

Step Nine: Regularly Examine the Fence for Damages

Your fence is something you see every day, but you may not inspect it every day.

Fences should be regularly examined to check for any damages. If there is a piece that is damaged and you do not see it right away, fungi or bacteria could cause the post to rot.

You can check your fence however often you want, but it is especially a good idea after a storm or if there is a windy day.

The inspection does not have to be intense or timely. All you need to do is walk around the border of your fence and see if there is any damages or spots where water could get into.

If you do see anything of concern, you should fix it as soon as possible. When there are damages, water can seep through and cause your fence posts to rot.

Just when you let your guard down about checking your fence is when a little bit of water could cause a lot of damage.

Tips and Tricks to Protect Your Fence Posts

  • Keep sprinklers away from the fence. If there is any way to keep your sprinklers away from your fence, you should do it. The less your fence gets wet the better. Especially if the sprinklers go off every day.
  • Use baking soda and vinegar to remove any fungus or algae to keep your fence clean and safe.
  • Some people will use plastic or metal barriers to protect their fence posts. This is one option, but it can be more expensive.

Just remember:

Whenever there is moisture, there is a chance to rot.

If you think about it, fence posts are in the ground, which is dark and wet. Dark and wet is a bad combination when there is wood around. Fungi, bacteria, and bugs thrive in dark moisture.

When wood is not properly treated and protected, it is exposed to the elements, where wood can rot easily.

That is why it is important to create barriers between the wood and the soil. A great barrier is concrete. Not only does it keep the wood away from the soil, it also soaks up any water or moisture that is near it.

Treated wood can last up to fifteen years, while untreated and unprotected wood only lasts about five years.

To prevent your fence posts from rotting and to save money down the road, follow the steps above.

We hope that this post has helped you protect your fence posts!

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