Putting up a fence can really change your yard, but getting the posts in right is super important. It’s not just about making the fence stand up; it’s about making it last. There are different ways to set fence posts, and how you do it can affect how long your fence stays looking good and doing its job. This guide will walk you through the common fence post setting methods, from digging the hole to making sure everything is solid.
Key Takeaways
- Choosing the right fence post setting method depends on soil type, climate, and the fence’s purpose.
- Proper site preparation, including clearing and grading, is vital for stable post installation.
- Excavating holes to the correct depth and diameter, and compacting the soil, are key steps.
- Concrete and gravel are common anchoring materials, each with pros and cons for stability and drainage.
- Local building codes and regulations must be followed for safe and legal fence installation.
Understanding Fence Post Setting Methods
When you’re putting up a fence, how you set the posts is a really big deal. It’s not just about getting them in the ground; it’s about making sure they’ll stand strong for years, no matter what the weather throws at them. Think of it like building a house – the foundation has to be solid, right? Well, fence posts are the foundation for your fence.
There are a few main ways people go about this, and each has its own pros and cons. You’ve got your classic concrete pour, which is super common and generally reliable. Then there’s the gravel or aggregate method, which some folks swear by for better drainage. And don’t forget about specialized anchors and brackets, which can be great for certain situations or soil types. The method you choose can really impact how long your fence lasts and how much maintenance it needs down the road.
Importance of Proper Post Setting
Getting this part right from the start saves a lot of headaches later. A fence post that’s not set properly can lean, loosen, or even fall over. This isn’t just unsightly; it compromises the entire fence’s integrity. It can lead to panels sagging, gates not closing right, and eventually, the need for costly repairs or even a full fence replacement. Proper setting means the post can handle the forces pushing and pulling on it, like wind or the weight of the fence material itself.
Variations in Fence Post Installation
Different situations call for different approaches. For instance, if you’re dealing with really wet soil, you might want to focus on drainage more than if you were in a dry, sandy area. The type of fence you’re installing also matters. A heavy wooden privacy fence will need a more robust setting than a light vinyl picket fence. Even the climate plays a role; areas with a lot of freeze-thaw cycles require special attention to prevent frost heave from pushing posts out of the ground. It’s all about matching the method to the environment and the job.
Impact of Setting Methods on Longevity
Your choice of setting method directly affects how long your fence will last. Concrete, while strong, can sometimes trap moisture if not done correctly, potentially leading to rot at the base of wooden posts over time. Gravel, on the other hand, allows water to drain away, which is great for preventing rot, but it might not offer the same initial rigidity as a well-set concrete post, especially in softer soils. Using anchors can be a good compromise, offering stability and allowing for some ground movement without compromising the post itself. Ultimately, a well-chosen and correctly executed setting method is key to a fence that stands the test of time. For more on fence installation, check out how to install a vinyl fence.
Site Preparation For Fence Posts
Before you even think about digging, getting the site ready is a big deal. It might seem like just clearing some brush, but it’s more than that. You need to know what you’re working with underground and make sure water isn’t going to become your fence’s worst enemy.
Assessing Soil Conditions
Different soils behave differently. Some hold water like a sponge, while others drain pretty well. You don’t want your posts sitting in soggy ground all the time; that’s a fast track to rot or frost heave, depending on where you live. A quick look at the soil can tell you a lot. Is it heavy clay? Sandy? Rocky? This will influence how deep you need to dig and what kind of base you’ll need at the bottom of the hole. Understanding your soil is the first step to a fence that lasts.
Clearing and Grading the Area
This part is pretty straightforward. You need to clear out any plants, rocks, or old junk that’s in the way. Then, you’ll want to grade the area. This means making sure the ground slopes away from where your fence line will be. If water pools up against your posts, it’s going to cause problems down the road, like rot or the ground shifting.
Planning for Drainage Around Posts
This ties into grading, but it’s worth its own mention. Think about where the water naturally flows on your property. You don’t want your fence posts to be in the path of a small stream after a rainstorm. Sometimes, you might need to add a bit of gravel at the bottom of the post hole, or even create a small swale or French drain nearby if you have a particularly wet spot. Good drainage is key to keeping your posts stable and preventing premature decay.
Excavation Techniques For Post Holes
Getting the hole right is pretty important for fence posts. It’s not just about digging a hole; it’s about digging the right hole. The depth, width, and how you deal with the soil afterward all play a big part in how sturdy your fence will be and how long it lasts. Mess this part up, and you might be dealing with leaning or even falling posts sooner than you’d like.
Determining Optimal Hole Depth
The depth of your post hole is probably the most critical factor for stability. A general rule of thumb is to dig the hole at least one-third of the post’s total length into the ground. For a standard 6-foot fence post, this means digging about 2 feet deep. However, this can change based on a few things. If you’re in an area with a lot of frost heave, you’ll want to go deeper, below the frost line, to stop the ground freezing and thawing from pushing your posts up. Also, if your fence is going to have a lot of weight on it, like a tall privacy fence or one that needs to withstand strong winds, you’ll want to dig deeper for a more secure foundation. Always check local building codes, as they often specify minimum depths for fence posts.
Appropriate Hole Diameter
Once you know how deep to dig, you need to think about how wide the hole should be. For most standard fence posts, a hole diameter that’s about three times the width of the post is usually sufficient. So, for a 4×4 post, a hole around 12 inches in diameter is a good starting point. This gives you enough room to work with when you’re setting the post and adding your concrete or gravel. If you’re using larger posts or setting them in very soft soil, you might want to go a bit wider to provide more surface area for the anchoring material to grip.
Soil Compaction Around Post Bases
How you backfill the hole is just as important as how deep you dig it. If you’re using concrete, you’ll be filling the hole around the post with it, but if you’re using gravel or just tamping soil back in, compaction is key. Properly compacting the soil or gravel around the base of the post provides crucial support and prevents shifting. You can do this by adding material in layers, about 6 inches at a time, and tamping it down firmly with a heavy object, like a piece of scrap wood or a tamper tool. This removes air pockets and creates a dense, stable base. For concrete, you’ll want to ensure it’s packed tightly around the post as you pour it, and then tamp it down to remove air bubbles. This step is vital for long-term fence stability.
Here’s a quick look at recommended hole dimensions:
| Post Size | Hole Diameter | Minimum Depth (Standard) |
|---|---|---|
| 4×4 inches | 12 inches | 2 feet |
| 6×6 inches | 18 inches | 2.5 feet |
Remember, these are general guidelines. Always consider your specific site conditions, climate, and fence type when deciding on hole depth and diameter. It’s better to dig a little deeper or wider than not deep or wide enough.
Concrete-Based Fence Post Installation
When you need a fence post that’s really going to stay put, concrete is often the go-to material. It’s a solid choice, literally, for making sure your fence posts stand firm against wind, weather, and whatever else comes their way. It’s not just about dumping some concrete in a hole, though; there’s a bit of a process to it if you want it done right.
Mixing and Pouring Concrete
Getting the concrete mix right is pretty important. You don’t want it too soupy or too dry. A good mix will be workable but still hold its shape. Most bagged concrete mixes will tell you how much water to add, so follow those instructions. You’ll typically mix it in a wheelbarrow or a mixing tub. Once it’s mixed to a consistent texture, you’ll carefully pour it into the hole around the post. It’s a good idea to have a shovel or trowel handy to help guide the concrete and fill any voids. The goal is to create a solid, monolithic base for your post.
Ensuring Post Plumbness During Setting
This is where you really need to pay attention. As you’re pouring the concrete and filling the hole, you’ve got to make sure that post is perfectly straight up and down. Use a level on two adjacent sides of the post. You might need to brace the post in place while the concrete starts to set. Sometimes, people use temporary wooden stakes or even just hold the post steady with a helper. If the post isn’t plumb when the concrete hardens, you’ll have a crooked fence, and fixing that later is a real pain. It’s much easier to get it right the first time.
Curing Time and Considerations
Concrete doesn’t just harden instantly; it needs time to cure. This is the process where the concrete gains its full strength. For fence posts, you generally want to let the concrete cure for at least 24 to 48 hours before you put any significant strain on it, like attaching fence panels or stretching wire. Full strength can take several days or even weeks, depending on the mix and conditions. You also want to protect the concrete from drying out too quickly, especially in hot weather, which can weaken it. Sometimes, covering it with plastic or keeping it damp can help with proper curing time.
Here’s a quick look at typical curing times:
| Strength Achieved | Timeframe (Approximate) |
|---|---|
| Initial Set | 2-4 hours |
| Handleable | 12-24 hours |
| Load Bearing | 2-3 days |
| Full Strength | 28 days |
Remember that temperature and humidity play a big role in how fast concrete cures. Colder weather slows it down, while very hot, dry conditions can cause it to cure too quickly if not managed.
Gravel and Aggregate Fence Post Anchoring
When you’re setting fence posts, especially if you’re trying to avoid concrete, using gravel and other aggregates is a solid alternative. It’s a method that’s been around for a while, and for good reason. It offers decent stability and, importantly, helps with drainage, which can really extend the life of your posts, particularly if they’re made of wood.
Layering Gravel for Drainage
The key to making this method work well is all about how you layer the gravel. You don’t just want to dump a bunch of rocks in the hole. Instead, you want to create a system that lets water escape. Here’s a basic approach:
- Start with a base layer: Put a few inches of coarse gravel at the very bottom of the hole. This gives water a place to collect and drain away from the post base.
- Add the post: Set your post in the hole, making sure it’s plumb and at the right height.
- Fill with gravel: Begin filling the hole around the post with more gravel. It’s best to use a mix of sizes, from pea gravel up to something a bit larger, like 3/4-inch crushed stone. This helps to fill voids and create a dense pack.
- Work in layers: Add the gravel in 6-inch increments, tamping each layer down firmly before adding the next. This is super important for stability.
- Top it off: Once you’re near the top of the hole, you can add a final layer of finer gravel or even some soil to help blend it in and prevent surface water from easily getting down into the main gravel fill.
Tamping Aggregate for Stability
Just throwing gravel in the hole isn’t enough. You really need to tamp it down. Think of it like building a solid foundation for anything – you want it to be dense and unmoving. When you tamp the gravel, you’re pushing the individual stones together, eliminating air pockets and creating a much stronger, more stable base for your fence post. This is where you get most of your holding power. If you skip this step, your posts might feel a bit wobbly, especially when the fence is under load or during windy conditions. A hand tamper works fine for smaller jobs, but for a longer fence line, you might consider renting a powered tamper if you want to save your back.
Advantages Over Other Methods
So, why choose gravel over, say, concrete? Well, there are a few good reasons. For starters, it’s generally easier to work with. You don’t have to mix anything, and cleanup is usually simpler. Plus, gravel allows for better drainage. Water can seep through the aggregate and away from the post, which is a big deal for preventing rot in wooden posts. This drainage aspect can significantly increase the lifespan of your fence posts. It’s also a bit more forgiving if you need to make adjustments later on. If you ever need to replace a post, it’s usually much easier to dig out gravel than it is to break up concrete. This method is a great option for many types of fencing, including privacy fences where stability is key installing a privacy fence.
While concrete offers maximum rigidity, the gravel method provides a good balance of stability and drainage, making it a practical choice for many DIY fence projects. The key is diligent tamping and proper layering to achieve the best results.
Alternative Fence Post Setting Methods
While concrete and gravel are common choices for setting fence posts, they aren’t the only options. Sometimes, you need a different approach, especially if you’re dealing with specific soil types, environmental concerns, or just want a faster installation. Let’s look at some of these alternatives.
Using Post Anchors and Brackets
Post anchors, often called post bases or post shoes, are metal connectors that attach to the bottom of a fence post and then anchor into concrete or a pre-set footing. This method keeps the wood post itself out of direct contact with the ground, which can significantly extend its life by preventing rot and insect damage. They come in various forms:
- Surface-Mount Anchors: These are bolted onto an existing concrete slab or footing. They’re great for decks or patios where you’re adding a fence.
- Embedded Anchors: These have a long spike or plate that gets driven or set into the ground (sometimes with concrete) before the post is attached. They offer good stability.
- Through-Bolt Anchors: These are designed to be embedded in concrete, with a bracket that the post is then bolted to.
The main advantage here is keeping the wood elevated, reducing moisture issues. It’s a good way to go if you’re concerned about longevity and want to minimize ground contact. You can find a variety of metal fence post anchors designed for different applications.
Dry Setting Techniques
Dry setting, also known as ‘dry packing,’ involves placing the post in the hole and then filling the void with a dry or semi-dry mixture of cement, sand, and gravel. Water is then added, and the mixture is tamped down firmly. This method relies heavily on compaction for stability and drainage.
Here’s a general idea of how it works:
- Dig your post hole to the appropriate depth and width.
- Place the post in the center of the hole.
- Mix your dry-set material (typically 1 part cement to 6-8 parts gravel and sand, with just enough water to make it clump when squeezed).
- Add the mixture around the post in layers, tamping each layer down firmly with a tamper or piece of scrap wood.
- Continue adding and tamping until the hole is filled.
- Plumb the post and brace it while the material cures.
This method can be quicker than pouring wet concrete, and it allows for better drainage than a solid concrete pour if done correctly. It’s often favored in areas with poor drainage or where freeze-thaw cycles are a concern.
Specialized Anchoring Systems
Beyond standard anchors and dry setting, there are more specialized systems designed for specific situations. These might include:
- Screw-in Ground Anchors: These large, heavy-duty screws are driven into the ground using specialized equipment. They offer strong holding power and minimal soil disturbance, making them a good option for certain soil types or when you want to avoid digging large holes.
- Precast Concrete Piers: While not strictly a ‘setting’ method for the post itself, precast concrete piers can serve as a foundation for post anchors. They are often used in areas with unstable soil or for larger structures.
- Helical Piles: Similar to screw anchors but often larger and engineered for significant loads, helical piles are screwed into the ground to a specific depth and torque, providing a very stable foundation.
These systems are often used in commercial applications or for projects requiring a higher degree of structural integrity, but they are becoming more accessible for residential use. They can be particularly useful when traditional methods are impractical due to soil conditions or site limitations.
Material Considerations For Fence Posts
When you’re putting up a fence, the posts are like the backbone of the whole thing. Choosing the right material for these posts is super important because it affects how long your fence will last, how much it costs, and even how it looks. You’ve got a few main options, and each one has its own pros and cons.
Wood Post Durability and Treatment
Wood posts are a classic choice, and for good reason. They look natural and can fit in with almost any backyard style. The most common types you’ll see are cedar, redwood, or pressure-treated pine. Cedar and redwood are naturally a bit more resistant to rot and bugs, which is a big plus. Pressure-treated wood has chemicals forced into it to help it last longer when it’s stuck in the ground.
- Lifespan: With proper treatment and installation, wood posts can last anywhere from 10 to 20 years, sometimes even longer if you’re lucky and the conditions are right.
- Maintenance: You’ll need to keep an eye on them. Wood can rot, warp, or get eaten by termites if it’s not treated well or if it’s constantly wet. Regular checks and maybe some sealant or stain can help.
- Cost: Generally, wood posts are pretty affordable upfront, making them a popular choice for many.
Wood posts offer a natural aesthetic but require diligent maintenance to combat moisture and pests, especially at ground level where they are most vulnerable.
Metal Post Strength and Corrosion Resistance
Metal posts, like steel or aluminum, are known for being really strong and durable. They don’t rot or get eaten by bugs like wood can. Steel posts, especially galvanized ones, are a common sight because they hold up well against the elements. Aluminum is lighter and won’t rust, but it might not be as strong as steel for really heavy fences.
- Strength: Metal posts can handle strong winds and heavy fencing materials much better than wood.
- Corrosion: While galvanized steel is treated to resist rust, it’s not completely immune, especially in salty or very wet environments. Aluminum is a better bet if rust is a major concern.
- Installation: They can be a bit trickier to cut and work with compared to wood, and you might need special tools.
Vinyl and Composite Post Properties
Vinyl and composite posts are newer options that are gaining popularity. They’re made from plastics or a mix of plastic and wood fibers. The big selling point here is that they require very little maintenance. They don’t rot, warp, or need painting, and they’re resistant to insects.
- Low Maintenance: This is the main advantage. Once they’re up, you can pretty much forget about them in terms of upkeep.
- Durability: They hold up well against moisture and don’t degrade like wood can over time.
- Appearance: While they come in various colors and styles, some people find they don’t have the same natural look as wood.
- Cost: They can be more expensive upfront than basic wood posts, but the lack of maintenance can make them cost-effective in the long run.
Ensuring Structural Integrity of Posts
When you’re putting up a fence, making sure those posts are solid is a big deal. It’s not just about how the fence looks; it’s about how long it’ll stand up to wind, rain, and whatever else the weather throws at it. Getting the posts right from the start saves a lot of headaches down the road.
Spacing Recommendations for Posts
How far apart you set your posts really matters. Too far apart, and the fence panels or wire can sag, putting extra stress on everything. Too close, and you’re just using more material than you need. For most standard fencing, like wood picket or chain link, spacing posts about 6 to 8 feet apart is pretty common. For heavier fences, like privacy fences with solid panels, you might want to bring them closer, maybe 5 to 6 feet. Always check what the fence material manufacturer suggests, as they’ll have the best advice for their specific product. It’s all about creating a balanced load distribution.
Bracing and Support During Installation
This is where you really make sure your posts are going to stay put. While you’re setting them, especially if you’re not using concrete, you need to brace them. Think of it like giving them crutches while they’re getting settled. You can use temporary stakes and boards to hold the posts perfectly straight (plumb) until the concrete cures or the soil is compacted. For taller or heavier fences, you might even need permanent bracing, like diagonal supports running from the post down to the ground or to a fence panel. This is especially important on sloped sites or areas that get a lot of wind. Proper bracing prevents any movement while the post is establishing its foundation.
Load Bearing Considerations for Fencing
Every fence has to handle some kind of load. Even a simple garden fence has to resist the outward pressure from the soil or the weight of climbing plants. A privacy fence has to deal with wind pushing against its large surface area. Chain-link fences might have to hold up under snow or ice. You need to think about the type of fence you’re installing and what forces it will face. This affects how deep your posts need to go, how strong the posts themselves should be, and how close together they need to be. For instance, a fence designed to keep large animals in will have very different load-bearing requirements than one just marking a property line. Considering these forces upfront means your fence won’t lean or fall over when you least expect it. It’s a key part of making sure your fence is a solid investment.
The structural integrity of your fence posts is directly tied to the quality of your installation. Proper spacing, effective bracing during setting, and a clear understanding of the loads the fence will bear are all critical steps. Neglecting these can lead to premature failure, requiring costly repairs or complete replacement. Think of it as building a strong foundation for any structure – it needs to be done right from the ground up.
Regulatory Compliance For Fence Installation
Understanding Local Building Codes
Before you even think about digging the first post hole, it’s a really good idea to get familiar with what your local government expects. Building codes aren’t just suggestions; they’re rules designed to keep things safe and orderly. For fences, this often means rules about how tall your fence can be, where exactly on your property line it can go, and sometimes even what materials you’re allowed to use. Ignoring these codes can lead to headaches later on, like having to take down a fence you just built or facing fines. It’s worth a quick call or visit to your town or county’s building department to get the lowdown. They usually have this information readily available, sometimes even online.
Permitting Requirements for Fencing
Depending on where you live and the type of fence you’re planning, you might need a permit. Smaller, purely decorative fences often fly under the radar, but anything substantial – like a privacy fence over a certain height, a fence around a pool, or a fence that borders a public space – usually requires official approval. The permit process typically involves submitting a simple application, maybe a basic site plan showing where the fence will go, and paying a small fee. Getting a permit is a way to ensure your project meets safety standards and doesn’t cause issues with neighbors or public access. It’s a small step that can prevent big problems down the road.
Inspections and Approval Processes
Once you have a permit, there might be an inspection phase. This usually happens after the fence is installed, but sometimes there’s an inspection before you start, especially if you’re doing significant groundwork or working near property lines. An inspector will come out to verify that your fence was built according to the approved plans and that it meets all the code requirements. This final approval is what makes your fence officially compliant. It’s the last check to make sure everything is safe and sound. Don’t skip this step if it’s required; it’s the official sign-off that your fence project is complete and legal.
Here’s a quick rundown of what to look out for:
- Height Restrictions: Many areas have limits on how tall fences can be, especially in front yards.
- Setbacks: You’ll need to know how far your fence must be from property lines, sidewalks, or streets.
- Material Rules: Some neighborhoods or towns have rules about fence materials, like prohibiting chain-link in residential areas.
- Utility Lines: Always call 811 before digging to locate underground utility lines. This is a critical safety step and often a regulatory requirement.
Navigating local regulations might seem like a hassle, but it’s a necessary part of any construction project. Think of it as building a solid foundation for your fence, not just in the ground, but legally too. A little bit of homework upfront saves a lot of potential trouble later.
Maintenance Of Set Fence Posts
Taking care of your fence posts after they’re set is pretty important if you want them to last. It’s not just about putting them in the ground and forgetting about them. Think of it like any other part of your property – a little attention goes a long way.
Regular Inspections for Stability
It’s a good idea to walk around your fence line a couple of times a year, maybe in the spring and fall. You’re looking for anything that seems loose or wobbly. Give each post a good shake. If one moves more than you’d expect, that’s a sign something needs attention. Also, check for any leaning or significant tilting. The goal is to catch small issues before they turn into big problems.
Addressing Soil Erosion Around Posts
Sometimes, rain and wind can wash away the soil right at the base of your fence posts. This can expose the bottom of the post and weaken its support. If you see this happening, you’ll want to add some soil back around the base. A slight mound, or a gentle slope away from the post, can help direct water away. This is especially important if you used a gravel or aggregate method, as that can sometimes shift over time.
Repairing or Replacing Damaged Posts
Posts can get damaged over time. Wood posts might start to rot at the ground line, or metal posts could get bent from an impact. If a post is showing signs of decay or significant damage, it’s usually best to replace it. Trying to repair a severely compromised post often doesn’t work out well in the long run. When replacing, try to match the original setting method as closely as possible for consistency.
Here’s a quick rundown of what to look for:
- Wood Posts: Check for soft spots, insect damage, or rot, especially near the soil line.
- Metal Posts: Look for rust, especially at the base, or any signs of bending or structural weakness.
- Concrete Footings: Inspect for large cracks or signs of the post shifting within the concrete.
Keeping an eye on your fence posts and doing these simple checks can save you a lot of hassle and expense down the road. It’s about proactive care for a long-lasting fence.
Wrapping Up Your Fence Post Project
So, you’ve put in the work to get those fence posts set right. It might have seemed like a lot at first, but taking the time to dig deep enough, get them plumb, and secure them properly makes a huge difference. A well-built fence starts with solid posts, and doing it the right way means your fence will stand strong for years to come, looking good and doing its job without you having to worry about it. It’s one of those things where a little extra effort upfront really pays off down the road.
Frequently Asked Questions
Why is it so important to set fence posts the right way?
Setting fence posts correctly is like building a strong foundation for your fence. If they aren’t put in deep enough or aren’t straight and stable, your fence can lean, fall over, or even collapse, especially when strong winds or heavy snow hit. Doing it right means your fence will last much longer and stay looking good.
What’s the best way to dig post holes?
The best way depends on your soil. For most areas, digging the hole about two to three times wider than the post and at least one-third of the post’s total length (plus a bit extra for frost heave) is a good rule of thumb. Make sure the bottom of the hole is wider than the top to help anchor the post.
Should I use concrete or gravel to set my posts?
Both have pros and cons. Concrete makes a very strong, solid base that’s great for high-stress areas like gates or high winds. Gravel, on the other hand, allows water to drain away from the base of the post, which can help prevent rot, especially in wet climates. Some people use a combination, with gravel at the bottom for drainage and concrete above.
How do I make sure my fence post is perfectly straight?
Use a level! Place a level against the post on two sides as you’re setting it. Have a helper hold the post steady while you fill the hole with your chosen material (concrete or gravel). Check the level frequently and make adjustments until the post is perfectly upright before the material sets.
Does the type of soil matter when setting posts?
Absolutely! Softer, sandy soil won’t hold a post as well as dense clay or rocky soil. In sandy areas, you might need to dig deeper or use more concrete to get a secure footing. It’s always a good idea to check the soil type before you start digging.
How far apart should fence posts be?
The typical spacing for fence posts is usually between 6 to 8 feet apart. However, this can change depending on the type of fence you’re building and how much wind or weight it needs to support. Stronger fences, like those for privacy or security, might need posts closer together.
What are some alternatives to using concrete?
You can use gravel, as mentioned, which helps with drainage. Another option is using metal post anchors or brackets that are driven or set into the ground, and then the post is attached to the anchor. These can be good for certain soil types or when you want to minimize ground disturbance.
How long until I can attach fence panels after setting posts?
If you use concrete, it’s best to wait at least 24 to 48 hours for it to fully cure and harden before attaching any fence sections. This ensures the posts are firmly set and won’t shift when the weight of the fence is added.
