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Dog Proof Fence Extension


SKU MM-HDPE-18-40-100

Designed to keep dogs from digging out from under the fence, our dog proof fence extension is constructed of heavy-duty HPDE plastic which easily attaches to the bottom of a fence. The material is available in thicknesses of 40 mil, 60 mil, and 80 mil and ships in 100’ rolls. The fence extension can be purchased in heights of 10", 18”, and 24” and can be easily cut down by the installer to mach the installation requirements.

To install the fence extension, dig a trench below the fence and place the barrier vertically in the ground. Next, attach the barrier to the bottom of the fence using washers and screws and then backfill.

The fence extension is made the in the United States.

Note: Our HDPE plastic is only available in roll widths up to 60 inches.

Please note that we are unable to provide custom roll lengths.

We also offer rigid HDPE in 48" x 96" sheets in both black and white colors.

View pricing and product info >

Product Info

  • Model: HPDE
  • Material: High Density Polyethylene (HDPE)
  • Size: Various
  • Free Shipping
  • Need a written quote? Request Online
  • Questions?  Call (800) 604-5537

Product Benefits

  • Waterproof
  • Commercial Grade
  • UV Resistant
  • Non-Biodegradable
  • Will Not Rot or Mildew
  • Resistant to Rodent and Insect Damage
  • 100 Year Material Lifespan
  • Made in the USA

Connecting HDPE Pieces

There are two ways to connect multiple pieces of HDPE together. One method is to overlap the HDPE and use our double sided seam tape to connect the two pieces. The other method is to butt the ends together and use our 17 mil single sided seam tape to create a solid connection.


Overlap Method
(for underground installations)

The overlap method is best used when connecting two pieces of HDPE in a buried application. Due to the overlap, a ridge is exposed which is not ideal when installed in exposed vertical or flat installations in high traffic areas as there is a possibility of an object catching on the ridge and pulling the two pieces apart.

In a below ground installation, the large overlap area provides a more water resistant connection as well as enhanced protection against tree and plant root intrusion.

View Tape Pricing and Seaming Instructions >

End to End Method
(for exposed installations)

When installing HDPE on a wall, floor or anywhere that is exposed, the end to end method provides a secure connection and does not leave any ridges exposed to potential catching by a person or object.

View Tape Pricing and Seaming Instructions >


  • All HDPE rolls ship for free (standard ground, see map)
  • Call: (800) 604-5537 for pricing and shipping questions.

    Shipping estimates shown on the map pertain to this specific product only. HDPE orders typically ship same day if the order is placed before 12:00 noon CST. Transit times displayed in the map are listed in business days, and are approximate. Transit times are subject to stock levels at regional warehouses.  The day that the order is shipped is not counted as a transit day.

    Shipping Map
    Friendly dog on turf

    Medium Sized Dog Standing on Turf

    Keeping Dogs from Digging Under Your Fence

    You have a dog that spends a lot of time out in the backyard surrounded by a fence. Unfortunately, your little friend is constantly trying to dig under the fence causing an incredible mess. In some cases, dogs will dig under fences just to see what's on the other side while others feel a threat while in the yard. There are solutions to stop this from happening but will need patience and a little creativity to bring this habit to an end. Here are some options to keep your pet from digging:

    To Begin With

    First off, you should find out why he is constantly trying to dig under the fence and then address it. As an example, maybe he's bored and needs some quality playtime and activities to keep him occupied. While there are options you can apply to stop this habit, there are other things you should not do.

    Reasons For Digging Under The Fence

    Once you understand what causes him to constantly dig under the fence, that's half the battle.

    Maybe He's Bored

    There are many cases dogs will dig under fences because they are literally bored. This is really true with dogs who are quite intelligent but are not happy just hanging around in your backyard.  Some breeds that dig more than others are German Shepherds, Border Collies, and Poodles. Just putting toys out back for him to play with will not do the trick.

    Possibly, he spotted a cat on the fence or a squirrel jumping from tree to tree. He is probably trying to get on the other side of the fence to chase down this new excitement. This is actually quite common among terriers and scent hounds.

    In other cases, some breeds have a built-in guardian tendency and feel an obligation to track down the predator they believe is a threat to you and his home. This is prominent among guard breeds of dogs so changing that perception can be a challenge.

    He Needs Companionship

    He needs the companionship of you and your family. Spending time with you is very important to him but that seems to be lacking. Your friend will turn to digging under the fence to find excitement beyond the fence because he's left alone all day long with absolutely no interaction.

    Seeking Mates

    If your dog has not been fixed, especially males, they will try to get out to find mates, it's only natural.  If they smell or hear a female outside the yard, they will try to dig their way out. Mating will usually take center place when they are in heat. Outside of the urge to mate, if he is anxious or stressed out, trying to get out of the backyard is a sign he feels confined.

    Your dog might feel panicked because he's trapped behind a fence and feels separated from anyone or anything. In many cases, this can come on during thunderstorms or other loud noises that frighten him, such as fireworks.

    Ways To Stop Digging

    Here are some great ideas to help keep your dog from digging under the fence. Some ideas take a little time to put in place. Investing in some creative ideas will keep your little friend safe.

    HDPE being installed on fence line

    Under Fence Dog Barrier Installation

    Friendly Goldendoodle in yard

    Dog In Backyard After Digging

    Existing Holes

    Dogs can be attracted to holes in the yard when you spot holes fill them in. If there are certain areas that automatically draw their attention. You can cover these spots with yard fixtures or maybe some landscaping. Chances are, it will deter him from digging over there.

    Fill In Gaps Under Sections The Fence

    If your dog continually tries to dig under the fence, try burying the bottom section of the fence with added soil. If there is space under the fence, filling it in will protect your dog from slipping out under the gap. Use one or two feet of soil below the surface to make sure your friend does not get out and possibly harm himself.  On the other hand, if your dog is a climber and you have a chain-link fence, you should place a large rock or other obstacles near the line of the fence to deter his climbing.

    Use Wire Along The Fence

    Attaching or burying some wire along the fence will create a barrier that your dog cannot dig around or under. An even better and more permanent solution is to install a fence extension at the base of the fence. The extension will act an an underground fence, prohibiting your dog from being able to being able to escape.

    Place Gravel Along the Bottom Of The Fence

    Gravel can be an uncomfortable experience for dogs to try and dig under. or around. Creating a top layer at the bottom of the fence might keep him from digging.

    Pour Concrete Down

    Having a layer of concrete at the bottom of your fence will prevent your dog from getting under it.  Dogs do not have the ability to dig through concrete.

    Choose A Dog Deterrent Alternative

    A dog deterrent spray is a great option to keep your pup at home. You will have to test a small unseen area of your privacy fence with the dog-deterrent spray to make sure there is no discoloration that can harm wood or other fence materials. This is one of the most effective ways to keep your pal in place.

    Another alternative if this spray is harming your fence, try diluting vinegar on the bottom of the fence. Even though this does not work with all dogs, it's certainly worth a shot as vinegar is very inexpensive.

    Plastic lining under fence

    HDPE Liner to Black Fence from Digging

    Create A Puppy Area

    There are plenty of dogs that dig just for pure enjoyment. If you can provide an area for him to dig and have fun and prevent his need to dig where he shouldn't. You can create a sandbox space that will not harm the rest of your yard. Dogs find it very rewarding to dig and many owners have been very successful in getting their dogs to pay attention to a different spot instead of trying to break their digging habits.  One word, you will probably have to take some time to train your friend in his new digging area, but it will be worth it.

    A Privacy Fence

    If you have critters around your house, you might want to invest in a privacy fence. Chain link fences can keep your dog in but they will give him a clear of the outside which will lead to his continuing to dig, and dig. You need to have a solid fence along with good preventative landscaping to stop this bad habit, ie thorny cactus.

    The Invisible Fence Option

    Even though it's a good idea to have a physical fence, some owners might want to look into options like installing an invisible fence. If you decide this is for you, keep in mind you will have to spend a good amount of time training your dog on how an invisible fence works. Some owners will opt for an invisible fence along with an actual fence.

    An invisible fence is not for all dogs or owners.  There are plenty of owners who do not want to put their little friends in a situation of being zapped every time they try to get out.

    Be Sure Your Friend Is Happy

    In some cases, your dog might be digging to cool off or needs a warm place to lie down. You might consider purchasing a doggy pool or a nice dog house to be happy and content. These ideas might even keep him from digging. If the temperature turns cold, make sure his dog's house has a warm blanket or bedding. In some situations, you might want to teach him to wear a jacket before going outside. Not all dogs want to automatically wear a doggy jacket.

    Ensure The Yard Does Not Scare Him

    Some dogs will try to get out because the yard scares them.  You need to understand any fears your dog has so he can relax in your yard.  Watch your dog's body language and habits to find out what is causing him to constantly dig. You can set up a camera to keep an eye out for what he's up to. Some dogs suffer from separation anxiety which can cover other things you might have to put in place. If you don't know what to look for or take care of, talk to a professional dog behaviorist to find out what's causing his fear.

    Small dog laying in yard

    Happy Dog in Backyard

    Prevent Digging Rodents

    Digging rodents can get into your yard teaching your pet how to dig out. Digging will also give your dog the desire to get out and chase them. Getting rid of digging rodents will stop the madness of digging as well. Just make sure whatever treatment you choose, your pet will be safe. To get the very best results, contact a pest control professional to help you out.

    Create A Fun Environment

    There's Always The Possibility Your Friend Is Bored

    If your dog is outside a lot of the time due to your work schedule, you need to give him some fun games and toys to entertain him while keeping him safe. Your dog's mental exercise is very important just like his physical exercise. Some activities your dog might enjoy include:

    Having puzzle toys filled with treats
    To play fetch, offer him a ball launcher game
    Have an obstacle course for increasing his agility
    Shred cardboard or other items that can be shredded

    In the evening when you are home, go outside and play together, he will love it!

    Create Some New Features To Your Landscaping

    If you are creating landscaping, just make sure you plant shrubs and other plants that are safe for your dog if he decides to chew on them. Be creative by placing rocks, gravel, and shrubs that will give your landscaping an attractive look while keeping your friend from digging up your fence.

    When Outside Watch Out For Him

    The bottom line, dogs need a lot of supervision when left to their own devices. Until you know he can be trusted on his own for a given period of time, you should keep an eye on him. If you can't be there all the time, hire someone who will look after him while you are gone. This will help to redirect his actions if he starts digging once again. Just like children, dogs must be trained and taught right from wrong. Above and beyond all else, make sure your yard is safe and comfortable for your very best friend.

    What Not To Do

    When training your dog how to act in the yard, there are things you should never do. Here are a few examples you should avoid:

    Do Not Punish Him Long After The Event

    You can't always be there to catch his bad habits but if it's hours later, he will not know what he did. It's one thing to catch him in the act of digging and redirect his actions but it will do no good if you yell at him long after the incident took place. All you will do is totally confuse him.

    Never Use Anything That Could Harm Your Dog

    Never use chemical repellents or poisons to stop his digging. Chances are you seriously harm him. Stay far away from any objects that are sharp or obstacles that will injure him.

    Never Tie Your Dog Outside And Unattended

    Tying your dog outside and leaving him like that is just wrong. If you are going to be around, you can use a long leash to teach him some walking skills but never leave him outside alone, he could be injured. Keep in mind, he is your friend so be his friend.

    Never Fill A Hole With Water

    First off, water will not keep the hole filled and he could get into exploring this water hole and possibly fall in and become injured. You need to fill the holes properly with soil that matches your landscaping or terrain.

    It can be somewhat frustrating if your dog is a constant digger but using a few good ideas can turn that around. Some good training sessions might just come into play and keep your friend safe when he spends time outside alone.