Frequently Asked Questions

Have FAQS about OZCO Building Products and how they can work with your outdoor living space or project? Browse these frequently asked questions we have collected over the years from our dealers, stores and customers.

Are Oz-Post® as strong as concrete?

Oz-Post® have been tested to high levels of horizontal forces and have been proven to be more than suitable for the majority of fencing and sign projects. A fence or sign constructed as recommended using Oz-Post® will be equally as strong as traditional concrete installation. A post placed in a standard 6”-8” post hole with one or two bags of concrete takes minimum of a ½ an hour to install. (not to mention a day to dry) This method is not any stronger than an Oz-Post® installed by one person in four minutes. Independent testing has proven that the weakest part of almost any fence installation is the wooden or metal post. This also holds true for an Oz-Post® installation. Testing has shown that the post will break or bend before the Oz-Post® fails. Of course Oz-Post® and 6”-8” post holes with concrete are not suitable for all fence designs or all signs but most standard fence designs and signs allowed by city councils can be installed with the Oz-Post® system. If you have any questions on the suitability of the Oz-Post® system for your next project feel free to call our customer service department for more information. There are fences, signs and many other projects all over North America that have stood the test of time. Many have been subjected to extreme conditions like the recent hurricanes in the gulf region.

How high can I go?

The maximum height of your fence has more to do with post spacing than your foundation. We recommend 6’ post spacing for a 8’ tall fence and 8’ spacing for a 6’ tall wood privacy fence. Other styles of fences like chain link, vinyl and ornamental simply follow the manufacturers recommended post spacing

What size and type should I use?

The size and style of Oz-Post® is determined by post materials that you intend to use. For some post sizes Oz-Post® offers several different styles for various applications. A good rule of thumb is to use the longest Oz-Post® that can be easily driven into the ground. The more firm and compacted the ground is the shorter Oz-Post® you will require. If you have a special application that you would like to use the Oz-Post® for let us know we more than likely have a special model for your needs. Note: the numbers at the end of the product name is the length in mm of the post. Many post sizes are offered in short and long lengths for example the T4-850 and T4-600 both accept the same size wood post but they are different lengths. The T4-850 is 34” long and the T4-600 is 24” long.

What happens if I hit Rock?

The Oz-Post® becomes an extension of your jackhammer. As a result it will break through loose shale and some rock. Smaller boulders will be pushed aside as the Oz-Post® penetrates the ground. You may need to straighten the assembly a few times as the Oz-Post® hits and deflects small boulders. Large solid bedrock and boulders cannot be penetrated by Oz-Post® without performing additional preparation to the ground. In these extreme cases you will have to move the hole, or try a shorter or tapered Oz-Post® or pre-drill a hole in the rock with a hammer drill, or use a chisel bit with the jackhammer to break up the underground obstruction. Remember a bobcat or post-hole auger will not penetrate most of the softer rock, asphalt or concrete that Oz-Post® can easily handle. Both Oz-Post® and traditional methods will not penetrate solid rock without specialized equipment or site preparation!

Can Oz-Posts® be removed?

Yes, Oz-Post® can be extracted if they are placed in the wrong spot, the fence needs moving, or they are only temporary. In lightly compacted soil conditions you can remove Oz-Post® by using a 6’ long pry bar. Place the pry bar under the housing, and using a piece of wood or a concrete building block placed approximately 10” from the Oz-Post® you can lever the post out of the ground. If this fails your Oz-Post® distributor can sell or rent an Oz-Puller™ to make this process much easier.

What if the ground becomes water logged?

Ground soil will expand and contract depending upon the water saturation levels. This is a natural property of ground soil and cannot be avoided. Due to the large surface area of the Oz-Post® fins there is a high level of adhesion of the soil onto the Oz-Post®. This helps to give Oz-Post® their lateral strength and support. Where the ground is very water logged you may notice some increased movement in your fence, as the ground dries this deflection in your fence will decrease back to usual levels. It should be noted that these effects and properties are also evident when constructing a fence using concrete.

How does wood shrinkage effect Oz-Post®?

Shrinkage in wood is a natural property, as moisture is absorbed and evaporated from the timber. This is not a concern as the Oz-Post® housing fully encapsulates the timber post and also allows for drainage. It is recommended that the hardware be tightened 2-6 months after installation to assure the tightest possible connection. The use of a small amount of polyurethane glue is a great option to allow for a strong connection without the need to re-tighten the screws. Please review installation instructions for the model that you are installing for all installation options. Shrinkage is a far greater problem when considering posts that have been secured using concrete. As the timber shrinks (the concrete does not) a concrete container is created which inevitably will hold water, thus your timber post becomes submerged until the water drains, a great environment for fungal decay. This is one of the reasons why posts rot out before the fence pickets and rails. Oz-Post® protect the wood posts from premature rot because they drain well and separate the wood from the soil.

What about Frost?

Oz-Post® perform excellent in both warm and cold climates. Frost is a force that can easily ruin any kind of post installation that is not done correctly. In areas that experience below freezing conditions evidence of damage caused by frost is easy to spot and very common. The best and easiest solution for this problem is Oz-Post®! Posts that have been installed with post holes and concrete can be “heaved” out of the ground by the freezing and thawing of the surrounding soil. If the buried concrete has rough sides frost can grab the post and heave it out of alignment and eventually completely out of the ground if it is left unattended. To assure that the concrete has smooth sides it is recommended that paperboard sleeves like “sono-tubes®” be inserted in the augured hole to produce smooth sides and help prevent movement from frost. The use of sono-tubes® is highly recommended for frost prone areas. This adds additional cost to traditional installations that should be considered when comparing with the Oz-Post® System. In addition to smooth sides it is recommended that the post hole have an enlarged bottom like an upside down mushroom. This technique reduces the likelihood of the post being heaved. This is very time consuming and costly as it increases concrete requirements and removal of excavated soil. WARNING – many fencing contractors and do-it-yourselfers do not install fence posts this way and that is why you can often see crooked fence posts and sign posts throughout your neighborhood. On the contrary the long, wide and smooth fins of an Oz-Post® give the frost nothing to “grab” onto to push it out of the ground. In addition, an Oz-Post® has a generally pointed shape and does not produce a horizontal plain for the shifting/expanding soil to push out of the ground. You can also think of it another way; it is much easier to push a pointed object into the ground (like an Oz-Post®) then it is a blunt object (a wooden post). With frost heaving the exact opposite principle occurs. When the sub-terrain moisture expands from below freezing conditions it can easily push the blunt end of a post and or concrete out of the ground but because an Oz-Post® is pointed with no blunt surfaces frost can’t push it out of the ground. Oz-Post® installations are far less likely to be heaved by the frost compared to the blunt and rough artificial rock that is formed with concrete. In addition to Oz-Post® tremendous long term performance in frost prone areas they can be installed even if the ground is already frozen!

Can Oz-Post® be used on a Gate?

Yes, Oz-Post® can be used for all kinds of gates that would normally be installed with a 6” – 8” post hole and concrete. This includes pedestrian gates up to 5’. If you are installing a gate that requires more strength there are several options you can use to obtain the desired stability. The simplest and possibly most effective method is to double up the posts on the hinge side of the gate. Placing two posts 10” apart will more than double the strength of the gate. Another gate strengthening technique is to join the top of the gate posts together with a header. These techniques are also a standard practice for installing with concrete. Of course if standard practice calls for a 12” or even 24” post hole with concrete then that post will have to be installed in that way. These are not common situations and in most cases will only be 1 or 2 posts on a job. In these situations the post strength is increased with the large surface area in contact with the surrounding soil (large diameter) and the increase in mass of the concrete. A 12” diameter hole will hold at least 8 bags of concrete which is 480 lbs. In addition a much larger and stronger post should be used to take advantage of the increased strength of the foundation. There is no use in digging bigger holes if you do not significantly increase post strength. To take full advantage of the Oz-Post® system we recommend that even if you have to concrete a post in the ground to still use Oz-Post® so that your post will be protected from rot.

Other Applications for Oz-Post®?

If you are considering using Oz-Post® for applications other than those specified in our literature please consult our customer service department. If we do not have a standard unit that is suitable for your needs our custom engineering department may be able to design and manufacture an Oz-Post® to suit your requirements.

How long will they last?

Oz-Post® are covered by a 25 year warranty against rust perforation. Oz-Post® are hot dipped galvanized and under normal conditions will outlast the expected service of the post that they support. Oz-Post® have a much thicker zinc coating than most common steel fence posts available on the market. Oz-Post® are also suitable for use with pressure treated lumber.

Do I need to have my utilities marked?

Yes, the Oz-Post® is driven into the ground 24”–34” and therefore you must call for locations of all utilities. This service is free and can be accessed nationally by calling 811 or your local utility companies.

Has Oz-Post® been tested?

Yes, Oz-Post® have been wind load tested to 120mph on a 6’ high wood privacy fence. The testing report is available in the download section of our web site.

Will Oz-Post® meet building codes?

You may be required to get a building permit in your area to build a fence. Building codes for fence construction generally relate to the height and style of fence that is allowed on your property. Most of these codes are intended to keep uniform standards throughout a community. Other concerns on fence construction are sight lines for drivers and also to prevent land owners from constructing a fence that would be considered an eye sore. Some cities have specifications for post holes for fence construction but most cases they will accept other equivalent alternatives like Oz-Post®. In terms of the “post hole” many cities require certain depths and widths for fence construction. In frost prone areas this is to assure that the post holes are past the frost line to prevent heaving and in high wind areas these regulations are to assure post stability. Because you are NOT digging a hole with Oz-Post® many of these codes do not generally apply. Most inspectors do not have any issues with the use of Oz-Post® because they are specifically designed, tested and engineered for fence construction. Oz-Post® also assures proper installation because it is difficult to “cheat” with Oz-Post®. Many contractors and homeowners do not follow the building code and dig their holes to the proper depth and width. This is the reason that post hole inspections are required for some fence construction projects. This is uncommon and in most cases is limited to commercial/government projects. Post inspections are not required for Oz-Post® because there is no post hole. In some areas especially high wind areas your inspector may request to see the wind load testing that is available for download on our web site. In all situations you should follow your local building code requirements. If your city requires 4’ spacing for fence posts or a maximum height of 6’ you will have to follow those codes. We recommend printing out the specification sheet for the Oz-Post® you are planning to use and include it with your building permit application.

What is an Oz-Hammer™?

Our exclusive Oz-Hammer™ is a high grade steel attachment that fits most common jackhammers. The Oz-Hammer™ transfers vibrating forces of the jackhammer to the Oz-Post®. You may need to get a Hammer-Spacer™ to adapt the Oz-Hammer™ to the Oz-Post® model that you are using. See our web site to determine which Oz-Post® require the Hammer-Spacer™. If you are planning to rent a jackhammer most rental centers have Bosch® Brute or Wacker® 60# electric jackhammers that are perfect for any size job. There are also gas powered jackhammers (Wacker® model BH-23 is one popular brand) that are great for remote locations where power cords or generators would have difficulty reaching. Air operated jackhammers will also work, but are not recommended because they are very heavy and much more difficult to handle. There are many other jackhammer brands and most of them will do the job. To be sure, the main feature that the jackhammer will need is to have a 1 ⅛” hex chisel holder with a retaining collar. Oz-Post® also offers our own Oz-Tools™ brand of jackhammer for those that want to purchase a jackhammer.

What is a Hammer-Spacer™?

The Hammer-Spacer™ is an adapter for the Oz-Hammer™. An appropriate Hammer-Spacer™ is REQUIRED for many Oz-Post® models. Please refer to your specific model to confirm if a spacer is required. You cannot install Oz-Posts that require a Hammer-Spacer™ without one. If you are planning to install your Oz-Post® with a sledgehammer the spacer is recommended for these installations as well.

How Does Oz-Deck™ Foundation System Work?

Oz-Deck™ utilizes the floating deck building technique. Floating deck construction is a similar concept as concrete patio or slab foundation on a house. Patios, slab foundations or drive ways do not have piers in the ground they rely on distributing the weight over a large area to prevent them from sinking in the ground. Oz-Deck™ uses the same principle of spreading the load for the deck over more square inches of earth compared to the alternative method of digging post holes and attaching a ledger to the house. With post holes and ledger construction one side of the deck is attached to the house with a ledger board that is bolted to the home. This requires special attention to assure that the board is properly attached to the home securely. Most deck failures occur because of improper ledger attachment. Oz-Deck™ is different because there is no ledger board required. The deck simply sits tight to the side of the home but is not actually attached to the home. This is why it is called a “floating deck”. With post holes there is a great deal of pressure exerted on the posts because there are less posts compared to Oz-Deck™. This is why it is very important that the piers be installed properly and why many cities require inspections of deck piers. You can understand the concept of a floating deck vs. a pier and ledger deck by thinking about the old trick of a circus performer lying on a bed of nails. If there are hundreds of nails in the board the weight of the performer is distributed over many points of contact and there is no pain or injury. This is similar to a floating deck. Alternatively if the same performer lay on a board with just a few nails he would become seriously injured. This is similar to a post hole and ledger construction. With Oz-Deck™ the construction of your deck is much faster and easier. Simply locate the deck plates where your posts are required and drive the Oz-Post® through them. In areas that do not get frost heave a ledger board can be used in conjunction with Oz-Deck™. The spacing between Oz-Deck™ must still be maintained even if the deck is attached to the home. The fact is that it is faster, easier and better to build a floating deck but there are options to attach your deck to the house if that is required.

Will the Oz-Deck™ Foundation System work on un-leveled ground?

Oz-Deck™ system is ideal for all types of terrain including areas that are un-leveled. There are very few backyards that are level most having a slope away from the home to promote drainage. Traditional deck construction techniques are used with Oz-Deck™ which makes it very easy to adjust for varying grade changes. This technique is posts that support beams, joists sit on the beams and the deck boards are fastened to the joists. After driving the Oz-Post® in the ground string lines are strung across all of the Oz-Deck™ systems at the desired height with a string level. This is an important step because this will make your deck posts all level. Simply measure from the string line to the base of the Oz-Post® and cut a piece of 4×4 to the exact length. Repeat this for all posts. When this is complete your deck foundation is level with no digging, no concrete, and no mess. The posts are now ready for the beams to be installed. This process is very fast and does not require high skill levels. Please refer to the instruction manual for more information. We also have a 30 min video on how to build a deck that can provide you with many of the tricks of the trade for your project. This video is available on You Tube, Amazon or by calling our office (866) 422-0751.

How high can I build my deck with Oz-Deck™?

Oz-Deck™ system can be used for decks that are up to 10’ high. 2’x2’ angled cross braces are required for all decks over 5’ in height. Note: Cross braces are also recommended for decks that are built with ledger boards and post holes.

Does the Oz-Deck™ Foundation System meet building codes?

When used according to Oz-Deck™ system recommendations, the Oz-Deck™ Foundation System conforms to all national and regional building codes when the deck is unattached from the house. Even though a state may have one building code, the city/county may choose to impose greater regulations and restrictions. The building code in your area may not expressly provide options for Oz-Deck™ installations. This does NOT mean that you can not use Oz-Deck™ in your area. In your application simply include a copy of the specifications and products that you plan to use to make the process move quickly When built according to Oz-Deck™ system plan specifications, the Oz-Deck™ system meets structural requirements for deck construction. They are strong, durable, and safe. Oz-Deck™ is designed to meet a minimum load rating of 52 lbs. per square foot.

What is the difference between Oz-Deck™ and pre-cast concrete deck blocks or pier blocks?

The main difference between deck blocks/pier blocks and Oz-Deck™ is the construction technique for building the structure of the deck. Deck blocks do not use beams to support the joist structure therefore deck blocks are required under every joist on no greater than 5’ spacing. For the average deck this requirement can add up to be twice as many deck blocks than Oz-Deck™ system for the same size deck. Deck blocks are also heavy and difficult to move into location and must be located perfectly level and in line under every joist. This is a time consuming and tedious task. Getting the deck joist framing square is also challenging with this construction technique. Because Oz-Deck™ uses traditional building techniques utilizing plans from deck magazines, books and web sites is easy to do. The only difference will be that with Oz-Deck™ there may be an extra beam. One other advantage is that Oz-Deck™ offers lateral load strength and substantial vertical up load resistance. Because the wood support posts are attached securely to the Oz-Post® there is no risk of the post becoming dislodged with the support. Oz-Post® also deliver substantial lateral load strength to keep long support posts stable. Deck piers offer no lateral load strength and no vertical load resistance because the support post or joist simply sits on the deck pier.

Is Oz-Deck™ available for post sizes other than 4×4?

Yes, Oz-Deck™ is now available for posts that are 4×4 and 6×6. Please take a look at our product page for more information regarding the T4-850 and T6-700 posts which are used in conjunction with the Oz-Deck™ plate.

What beam and joist sizes should I use?

For the beams it is recommended to nail 2 – 2×8 boards together to make the beam and rest them on top of the post and attach with steel connectors. 2×6 boards can also be used but may require closer spacing of beams to comply with your local building code. If the deck is going to be very low profile the beams can be mounted on the sides of the posts and attached with large bolts and/or brackets. Spacing between the boards should follow building code and manufacturers guidelines (for composite decking). Generally 2×6 decking boards can be on 24” centers and 5/4” and composite decking should be on 16” centers.

Can I install a hot tub with Oz-Deck™?

Yes, Oz-Deck™ Foundation System can be used to support the load of a hot tub. In the area where the hot tub is going to be located it is required that the beam and post spacing be decreased to 3’ centers. Also it is recommended to install extra Oz-Deck™ plates so that there is a minimum of 6 under most standard hot tubs. For larger tubs or other special projects call customer service.

How long does the Oz-Deck™ system take to install?

The actual installation of an Oz-Deck™ is about 2 min. but for project planning about an allocation of 10-15 min each post should be expected. So for a standard 12’ x 12’ deck that will require 9 Oz-Deck™ plates you should have all of the piers in place in about 2 ½ hours. We have taken into account the time to run string lines and locate the post locations and cutting the posts to the proper height. It is assumed that this process is being done by two people. After the posts are in the rest of the project is very fast. Making the framing for the deck and squaring it up is easy and then all that is left is the deck boards. A basic 12’ x 12’ can easily be completed in one day by two people.

What does frost heaving and thawing mean?

Frost heave is caused by water that is trapped underground in layers of soil that have become frozen. When the water freezes it expands causing the surface to move vertically. This natural occurrence can cause the surface to move up to ½” in the winter and back to the original location in the spring when the frost thaws. Even if you live in a warmer climate like Texas, the principles are the same. The soil will expand and contract with temperature and moisture changes in the soil. This is less of a problem in these climates, but movement can occur.

What effects does frost have on conventional deck construction?

When footings are not buried below the frost line or without smooth edges, damage can occur. During cold seasons, ice lenses form, exerting pressure against the rough edges of the concrete post, forcing it upward. A pocket will form under the post where the soil is not affected by frost. Dirt particles and water will then accumulate into this pocket. During the spring thaw, it is likely that the post will not return to its original position (due to the accumulation of soil deposits). When repeated throughout the life of the deck, this process of lifting the post can cause significant damage to the structural integrity of the deck.

How is frost heave prevented?

The standard method is to anchor the post down by digging a large hole to or below the frost line. The shape of the hole should be like a bell. The hole must wider at the bottom than at the top. This is difficult to do but is typically required by building codes. If this is not done correctly, there will be heaving over time which could damage your structure. Building inspectors will often require “hole” inspections to make sure that it has been dug correctly significantly adding to the time necessary to build your deck.

What effects does frost have on the Oz-Deck™ Foundation System?

The Oz-Deck™ system performs excellent in frost areas. The compaction of the soil, long fins and large heavy weight distribution plate performs equally as well as other post foundation methods. The deck may move slightly up and down through seasonal cycles. This up down movement is very minimal (it may not even occur) and will not be noticeable.

Will my deck move sideways or pull from the house?

No. When frost heave occurs, the forces in the ground have nowhere to go except up. The deck may move slightly up and down through seasonal cycles, but not from side to side. This up down movement is very minimal and will not be noticeable. The long wide anchor in the ground prevents any side to side movement. A deck built with Oz-Deck™ will not move away from the house when installed properly.

Should I put anything under the Oz-Deck™ piers?

It’s not necessary to put anything under the Oz-Deck™ piers. They can sit directly on top of the soil or grass. The use of a jackhammer to install the Oz-Deck™ post is recommended because as the Oz-Post® reaches the Oz-Deck™ plate it compacts the top soil and removes any air pockets in the soil providing a sturdy foundation. If you want to put something on the ground you can put fine gravel on the surface.

Will my deck sink?

Even on poor soil conditions, your deck will not sink. Oz-Deck™ foundation system is designed to distribute weight EVENLY across the ground. It is essential that you follow the recommended spacing of Oz-Deck™ piers. Oz-Deck™ compacts the soil with the force and vibrations of the jackhammer installation so even poor soils are stabilized with the Oz-Deck™ system. Oz-Posts have been utilized in wetlands and marshy areas with excellent long term results. If you have questions in regards to the suitability of Oz-Deck™ for your project feel free to call our customer service department for assistance.

My local building code requires footings. What do I do now?

The traditional method for installing a deck is to dig a hole and set a footing. There are many new/alternative products that are available that may not be expressly written into the building code that can still be used. The building codes have been developed over many years and are intended to set standards for construction. It takes many years for new products to get written into the code but that does not mean that they cannot be utilized. In most cases your local building department will accept other construction methods as long as you provide if requested any additional engineering documentation that they may require. We are not aware of any situation where Oz-Deck™ system has not been approved for a deck project. In rare circumstances the building department has required post spacing that is different than our recommendations but this was mostly due to unique site conditions that are not common for most installations. In frost prone areas is important that make it clear that you will be building a “Floating Deck” and that you will not be attaching the deck to the house. It is extremely unusual for a local building code to require footings for all types of deck construction. Typically footings are required if the deck is attached to a fixed object, similar to a house. A floating foundation is a different building method and clarification with the inspector should resolve any potential problems. The inspector may also require additional technical information that is available in our Download section.

Can I use Oz-Deck™ for a gazebo or open roof structure?

Open roof structures can act like an umbrella can cause uplift in high wind. Oz-Post® may not offer adequate uplift resistance for this type of roof structure. Call our customer service line with details of your project if you are unsure if your project will be unsuitable for Oz-Deck™. Open arbors and pergolas where wind can easily pass through can be built with Oz-Deck™ also closed structures like a garden shed are acceptable.