Recently at Nelson Port, Interbloc units were subjected to a significant real-world impact after being struck by heavy machinery, involving an excavator weighing approximately 30 tonnes.

Despite the force of the collision, the Interbloc blocks remained standing, clearly demonstrating the inherent strength, stability, and resilience of the system.

This incident highlights the safety and performance benefits of reinforced Interbloc systems, which are engineered not only to retain ground but also to protect people, assets, and operational continuity in high-risk environments such as ports, industrial sites, and transport hubs.

Real-world events like this provide powerful validation of why properly engineered, reinforced infrastructure solutions matter. In locations subject to heavy plant movement and constrained operating conditions, the consequences of failure can be severe. In this instance, the robustness of the Interbloc system helped mitigate what could have been a far more serious outcome.

At Envirocon, we are proud to supply and support Interbloc solutions that perform when it matters most, delivering confidence, safety, and resilience in demanding applications.

A major storm event on the West Coast recently caused widespread disruption, cutting all road access into and out of the region. Several critical routes were closed due to significant slips and underslips, including State Highway 6 near Coal Creek, south of Murchison, leaving communities and freight operators isolated.

At this location, the rapid reopening of SH6 was critical to restoring connectivity for local communities and maintaining essential freight movements. The speed and effectiveness of the emergency response were made possible through the use of Interbloc precast concrete blocks, which enabled the fast construction of a temporary single-lane carriageway capable of carrying heavy vehicles.

One of the key advantages of the Interbloc solution was local availability. Interbloc units were already stockpiled at Fulton Hogan’s Appleby Quarry, allowing construction crews to mobilise immediately. This eliminated the significant delays that would have occurred if materials had needed to be transported from Christchurch via Blenheim, enabling repair works to begin without delay and the highway to reopen sooner.

This project demonstrates how modular, reusable infrastructure systems such as Interbloc can play a vital role in emergency response and network resilience, particularly when supported by strategic local stockpiling. The ability to deploy a proven, heavy-duty solution at short notice was instrumental in reducing downtime on a critical transport corridor.

Credit goes to Fulton Hogan and all crews involved for their efficient, safe, and highly effective work under challenging conditions.

The newly installed Croatia-texture Interbloc+ retaining wall at Northcote College is a standout example of how modern precast systems can deliver both structural performance and architectural quality. Installed only a few months ago, the wall is already demonstrating the durability, stability, and visual refinement expected from the Interbloc+ product range.

Positioned alongside one of the school’s main buildings, the retaining structure supports significant elevation changes while presenting a clean, cohesive appearance that enhances the overall site. The Croatia texture — inspired by natural stone — adds depth and character, helping the wall blend seamlessly with both the landscaped terraces and the contemporary architecture of the college.

Engineering Performance with an Architectural Edge

The Northcote College project highlights the versatility of Interbloc+ in delivering two key outcomes:

The interlocking design of Interbloc+ enables rapid installation and reliable long-term behaviour, making it ideal for environments where safety and durability are paramount.

Designed for Schools and Public Facilities

Schools require infrastructure that is safe, resilient, and low-maintenance. Interbloc+ systems meet these demands through:

At Northcote College, the retaining wall is performing exactly as intended — supporting pedestrian circulation, tiered outdoor areas, and seating zones while maintaining an architectural finish that enhances the everyday environment for students and staff.

A Strong Example of Interbloc+ in Action

This installation demonstrates how the Interbloc+ Croatia texture can transform a functional retaining structure into an architectural feature. The result is a safe, durable, and visually cohesive space that reflects the standards increasingly expected in modern educational and public facilities.

Interbloc+ continues to prove that high-performance engineering and high-quality design can — and should — go hand in hand.

Situation

Waste Management is New Zealand’s leading provider of waste disposal services. Its purpose is to collect, transport, treat, recycle, recover and dispose off residential, commercial, and industrial waste. They operate facilities throughout the country dedicated to storing and processing all sorts of waste, from ordinary residential to liquid and hazardous waste.

In one of Waste Management facilities is a pond used for collecting water generated during the waste dewatering process. Recently, there has been an increase in waste inflow which raised the capacity requirement for the pond. This required for the pond to be modified to keep up with the inflow and improve the efficiency of its dewatering capacity.

Solution

The modification of Waste Management’s existing pond involved dividing it into to separate halves and adding an end extension. To do this, they considered a few options:

Waste Management found the Interbloc Modular Wall System to be the ideal solution for this project. The box-pour method was prevented by the existing pond’s central wall height, while using pre-poured tilt slab proved too costly.

Using the Interbloc Modular Wall System allowed for the pond to be modified easily and cost-effectively. The system was quickly assembled despite the challenging environment of the pond. The installation process simply involved lifting the blocks into the pond using the lifting anchor and assembling them in the pond using a forklift.  Ross, Waste Management’s Production Supervisor described the installation of the system an “easy, hassle free process”.

Benefits

Apart from the efficient installation process provided by the Interbloc Modular Wall System, Waste Management also obtained extra benefits for using Interbloc.

The modular quality of the blocks, along with its lifting anchor component, allowed for the structure to be safely installed. “Safety is held as our highest priority and value at Waste Management”, said Ross.

Furthermore, the modular quality of the blocks also provides Waste Management with the option to modify the pond in the future without any major construction.

Waste Management was also able to reduce their environmental footprint by using Interbloc’s Modular Wall system. Interbloc as a supporter of the Envirocon Product Stewardship Scheme provided them with environmentally sustainable products, which is line with Waste Management’s purpose of tackling New Zealand’s waste.

Liveable Streets is a joint venture between HEB Construction and Higgins Contracting. Its primary goal is to deliver the Central East Road Corridor Maintenance Contract for Auckland Transport.

The Liveable Streets team is tasked with general maintenance, emergency management, renewals, rehabilitation, road rails, kerbs, crossing, and spill response.

Early in 2022 heavy rains resulted in landslides in Whitford, Auckland. Just 7m from the slippage site on Whitford Road, was housing. With further heavy rains expected, there was an immediate threat to property. There was also the added potential risk of damage to nearby power/utility lines which needed to be considered in the solution’s design. To keep the residents and community safe, a protection wall needed to be erected, fast.

Interbloc to the Rescue

Envirocon’s high productivity, quick reaction Interbloc Precast Concrete Wall System was chosen. When compared to the other options - timber and gabion baskets - it was a no brainer. Both legacy construction systems were too slow to install.

In contrast Interbloc allowed for rapid deployment, with trucks rolling in one after the other offloading blocks which were installed in real time. In just 4 days, 337 blocks were installed to build a wall 2.4m wide, 2.4m high, and 20.4m long.

The Liveable Streets Team installing a temporary slippage solution

Wall being installed by the TWC Contracting team

The wall will be in place for an uncertain amount of time and subject to high loads and hydrostatic pressures. Interbloc’s inherent flexibility added additional benefits. A unique block stacking configuration was required, eliminating the need for vertical reinforcing. This aided the speed of installation without compromising structural integrity. Interbloc mortarless interlocking system also allows for water to drain through the wall.

Another key benefit for Liveable Streets is the ability to non-destructively dismantle the wall with ease at any stage in the future and reuse the blocks for another structure or take advantage of Interbloc’s industry leading Buyback Guarantee.

Finished Interbloc Slippage Wall

Liveable Streets is an excellent example of the suitability of Interbloc for emergency slip management - a common problem faced by road maintenance contract holders across New Zealand. Similar solutions have been provided throughout the Waikato and Marlborough.

Interested to know more? Get in touch today.

“At Daltons we are the best in our field and we like to deal with the best and that’s why we chose Interbloc” - Kerryn, Auckland Area Manager

Daltons is one of New Zealand’s largest landscape supplies businesses. Their products range from fertiliser and compost to aggregate and mulch. Key to Dalton’s success has been their investment in state-of-the-art manufacturing systems and commitment to quality. Tidy, flexible, and efficient bulk materials storage plays a small, but important role as well. Since 2008, Daltons have chosen the Interbloc precast wall system to build their storage bins.

Daltons Interbloc Bin

(Interbloc Bin for Daltons Landscape Supplies' Christchurch Yard)

One of the most common solutions that Daltons has used is Interbloc bins. A natural benefit of the bins is it separates their product, making it easier to pick out what’s needed. That’s not the only reason why they chose Interbloc, though. A key plus for them has been the flexibility in the system. Giving them the ability to grow (or shrink) their bins as needed.

“ We can change it. If our bins are too small, we can make them wider, it’s just putting in another footing, putting the rods back in, and restacking them” - Kerryn Gibson, Dalton Landscape Supplies Auckland Area Manager.

Daltons has used the Interbloc solution time and time again. So when it comes to designing or redesigning their yards, it’s easy. This is largely thanks to Interbloc’s intuitive and simple modular design. With the blocks’ interlocking shear key, it is quick and easy to build structures.

Cleanliness is also an important factor for landscape yards. Landscaping is all about creating a space where aesthetics are important. To fit this concept, storage solutions need to create a clean and organised environment. Interbloc fits the brief largely because of its modular design.

“The tidy aspect is something for a landscaped yard. You want to stand out and look good”

If you’re wanting a well-organized landscape yard that suits your current and future needs, get in touch:

https://www.envirocon.co.nz/pages/contact-us

We also offer other Interbloc solutions, some of which are:

Fulton Hogan is one of New Zealand’s leading civil contractors. They have a deep commitment to building the infrastructure that powers economic growth. Most recently, this has meant they’ve expanded asphalt production at their Silverdale plant in the rapidly expanding area of North Auckland. Key to asphalt production is aggregate storage. Envirocon’s Interbloc wall system was used to build flexible, durable, and safe storage bunkers. 

When additional aggregate storage was required at Fulton Hogan’s asphalt manufacturing plant in Silverdale, the company specified Interbloc. It was a no-brainer - Fulton Hogan has extensive experience utilising the Interbloc system throughout the country for similar purposes.

12 bins of varying sizes were constructed from the Interbloc precast wall system, giving an additional capacity of 1,750m3 of aggregate storage, equal to 2,750 tonnes of material. 

Fulton Hogan Silverdale Aggregate Bins

(Looking straight onto the finished Fulton Hogan Silverdale aggregate bins)

To complicate matters, the bins had to be built at the top of a 3m high retaining wall on three sides.  The combined weight of the filled bins and the backfill material meant that engineers needed to be satisfied that the retaining walls would be able to handle such loads, especially since unsuitable base soil meant retaining walls had failed in the past. Interbloc showed its unique versatility by allowing high surcharge capacity reinforced earth walls to be built by simply casting geogrid into the blocks during the manufacturing process.

“Due to the steep topography of the landscape, a retaining wall was constructed out of Interblocs to provide a level surface for the aggregate bins to be built on,” explained  Fulton Hogan's Project Engineer Oli Brooks. “Geogrid was used in the backfill behind the retaining wall, and tied into the blocks. Granular backfill (DQ65 which has a compacted dry density of 2.14tonnes/m3 ) was then placed and compacted in 150-200mm layers, with geogrid installed at each Interbloc row ", explains Envirocon’s Peter Fowler. 

Geogrid being installed on the Fulton Hogan Silverdale retaining wall

(Fulton Hogan employees installing geogrid reinforcing for the retaining wall)

The asphalt plant had to remain in production throughout the expansion process. As a result, the 20-year-old storage yard had to be deconstructed in stages. This meant temporary bins were built using Interblocs, in a different area of the yard, to accommodate some of the material while the full operation of the plant continued. These blocks were then re-used at the final bin sites. 

This project was the first to use the new Interbloc base block for the storage bins. The combined forces of the product, the height required to store materials in the footprint available - and to provide support for a fixed roof – meant base blocks could spread the wall load over a bigger footprint, delivering greater design efficiency.

Retaining Wall and Base Blocks at Fulton Hogan Silverdale

(Holding the aggregate bins (with the new Interbloc Base Block) up is a 3m long retaining wall)

All bins were assembled on-site, and Brooks felt the process was “pretty straightforward - the 3D drawings helped significantly,” he said. This was critical as the density of stored aggregates varied between 1.4 to 2.3 tonnes/m3.

“The new layout and storage volumes have removed the safety and storage problems, and future-proofed it for many years to come,” said Peter Fowler proudly.

Fulton Hogan Silverdale Aggregate Bins

(The finished aggregate bins at Fulton Hogan Silverdale)

 

The Interbloc system easily absorbed the loadings required of such a structure, and the team found its construction very straightforward.

The number of 3D drawings of the block layouts supplied by Envirocon really helped the team visualise what they were building, said Brooks. “This made the whole process go a lot more smoothly.”

Brooks particularly praised the support received from Envirocon during the build. “The Interbloc team, specifically Peter and Cole, have been very responsive and accommodating to design changes and last-minute requests,” said Brooks. “And the 3D drawings of the block layouts were very helpful for the site team to visualise what they were building.”

Wyatt Landscape Supplies is the latest addition to the Wyatts Haulage group based in Warkworth, north of Auckland. Key to setting up and running a landscape supplies yard is a well organised site for you and your clients to navigate easily, and the flexibility to rearrange bins as demand for materials change.

Traditionally, building bulk storage solutions is expensive, time consuming and inflexible. Interbloc offers an antidote. Faster to install and easier to rearrange whenever a change is required. 

Wyatt Landscape Supplies had used the Interbloc system before, and knew it would be right for the aggregate bins at their new landscape yard. The company stores a range of aggregates including metals and scoria, sand and lime, and landscaping pebbles, mulches and mixes - some of which are also under cover. Each bin measures between 5000mm wide x 4500mm deep x 1800mm high and 3500mm x 3500mm x 1800mm, depending on the product being stored.

Dave Wyatt, Managing Director of Wyatt Landscape Supplies, knew that whenever he needed to re-configure the site it would always be quick and easy, because of how easy it is to assemble and rearrange the bays. A ‘nice’ added extra was the sustainability credentials entrenched in every Interbloc block – made from 100 percent recycled wet concrete, every block contains zero embedded carbon.

At the heart of the Interbloc precast concrete wall system is a unique interlocking concrete block. The block delivers a high productivity system, meaning Interbloc customers can build faster, stronger, safer. The certified, central lifting anchors built into each Interbloc block help with moving them safely, and also serve as anchor points for ropes and strops. The blocks have excellent horizontal shear strength in both directions, which helps them withstand any knocks and bumps from forklifts or other mechanical machinery. 

No specialist heavy-lifting cranes are required when constructing the bins - the right forklift is capable of constructing Interbloc walls like this, and the blocks “pull apart” like LEGO so that no destructive dismantling is ever required, and the blocks can be reconfigured endlessly.

“We’re so confident in our system and blocks we offer a unique buyback guarantee,” explains Envirocon’s Sales Director Jack Bright. “This buyback guarantee means when you no longer require the blocks, you’ll be able to trade them in for cash.

Lex Norton owns and operates the lime prill storage facility for the far north located in Kaikohe. The bin has a capacity of 500 tonne and was constructed in February 2008 using Interbloc in combination with a simple externally supplied shelter roof.

Although the Interbloc solution is able to keep gods dry in combination with a suitable roofing structure, it is imperative that Lime prills be kept dry so the Interbloc team sealed all joints between the blocks for added comfort for the client. Jack Bright said, “Our solution can be customised to meet the clients needs and the ability to seal for added product protection is a good example of being able to meet the customers need correctly and without additional complexity”

Lex Norton said that he chose Interbloc for many reasons, they included,

● Strength of the blocks to withstand the odd hit from the loader,
● They where free standing
● Assembly could be carried out with their fork lift,
● The product was competitively priced compared to other solutions
● The ability to expand and or relocate the bin at a future date.

When asked to summarise the process and his dealings with Interbloc, Lex stated “I was very happy with the Interbloc fertiliser bin and would recommend Interbloc structures for smaller farm storage requirements”.

Situation

Errol Watts is a typical Te Puke farmer. Born and bred in the region, Errol farms a total of 295 hectares across two sites. Milking 1200 cows means Errol requires
supplementary feed to ensure maximum productivity throughout the year. One
of the supplementary feeds utilised by Errol is Palm Kernel Expeller (PKE). PKE’s a bit like fertiliser, in that it is highly susceptible to moisture damage. When you’re dealing with a product that costs around $300 a tonne, reducing waste is important. Achieving cost effectiveness and weather tightness weren’t the only concerns of Errol’s. A company which could handle the project from start to finish was also important, “Service matters, and with Interbloc you get good service” says Errol.

Solution

Errol had previously contracted Interbloc, so when he went looking for a new
PKE bin he took the time to look into Interbloc’s standard PKE bin package. As
Errol puts it “They did some work for me a couple of years ago so when I found I
needed a PKE bin and saw Interbloc’s PKE bin all in one package I gave them a
call”. The standard PKE bin was designed by Interbloc in conjunction with
farmers. It is a 48m³ bin made from Interbloc interlocking concrete blocks. The
the walls are 600mm wide for strength and stability. The price tag includes a
concrete slab with a 2m apron to ensure any spillage out the front doesn’t go to
waste. The bin utilises a heavy duty canvas cover which five removable
galvanised steel hoops to keep it taunt. The hoops slide into hole locates on the
top of the bin. The canvas cover is attached for the bin at the back and is easily
pulled back and forth. All this can be installed quickly – one day once the
concrete slab has been laid.

If you ask Errol, the features of the standardised bin weren’t the deal maker, “it
was a no brainer. Firstly the blocks are a brilliant idea. They’re convenient,
durable, and flexible. When I am not using the PKE bin for feed storage, I can use it to store fertiliser or something else. It’s not just a bin, you see, because of the modular design of the blocks we can use the blocks to build other structures any
time”.

Errol’s story is typical of the farmers who have purchase Interbloc PKE bins.
Modern farming means Interbloc solutions need to cater to a variety of on farm
requirements. The standardised design means Interbloc can offer a competitively priced product and this shows in sales to day. 

Benefits

When Ruawai pedigree Holstein breeders and dairy farmers Blair and Neil Sidwell needed to build a new maize silage bin they called on Interbloc for the solution. With 35 years farming experience the Sidwells know what they want when it comes to their business, and Neil was quite precise. “Build us a silage bin, forty by twenty, by one point two metres high!” he said.

Once the floor was poured, and the required number of blocks had been transported to the site, the Interbloc team had built their bin within two days, and it was full of good maize silage, safe and sound, two weeks later. Before committing themselves to building an Interbloc maize silage bin, the Sidwell brothers went through an extensive cost comparison process, from which Interbloc emerged to beat the nearest competitor’s price by 50%.

Combining this factor with the flexibility and durability of its products, and the speed of the Interbloc operation was, as the Sidwells’ said, “… a no-brainer!” Like the Sidwells’, more and more farmers now recognize the advantages of the Interbloc silage bins over the alternative in-ground pits.

“No more mud contaminating the precious resource, which on a bin this size (1000M3) can lead to silage losses of up to 30%, or $23000,” said Interbloc’s Jack Bright. “The approaches to the new bin are clean and tidy, and with a more even compaction of the silage, its quality is maintained.

And the Sidwells are better able to more efficiently and economically deliver it to the Stock.” Blair Sidwell was also very pleased with the Interbloc solution and noted that when the planned increase in herd size takes place they will be able to easily increase the bin’s capacity with the simple addition of another row of Interblocs.

Good silage stack management is essential if best results are to be achieved. A poorly designed pit or bunker not only adds to wastage but also increased the workload involved with feeding out. “The objective must be to do it right first time,” says Jack Bright, who has been in the industry for over 15 years and shares some of his experience here.

The Sales Director, Bright says, “farming has become big business, farmers have to maximise the return they get from every dollar. If they don’t adapt” he says, “they’ll be left in the wake of those who do!” “Good farming is all about maximising potential for quality production and consequent profit, and minimising factors that could adversely affect those goals!” says Bright.

A properly specified and constructed silage bunker ensures greater and more even compaction so, in the case of maize silage, farmers can achieve an average density of 225kg DM/m³ compared with less than 200kg DM/³ when stacked Otherwise. Positioning the bin handy to where the silage will be fed out is important, and so is its orientation to prevailing wind, rain and sun. And it’s also important that the site is able to be easily accessed by large truck and trailer units and that the surrounding ground is firm. And while harvesting maize at the right time will minimise any leeching to almost nil, it’s also important to make provision for the water to be drained away from the site. *Based on a tractor bucket reach of 2.5m high and a twin U bin structure – the most economical and easiest to build. Actual bunker size will be determined by each individual farmer’s herd management practices but ideally 15 – 20cm
of the face should be removed each day and the whole face every 24 hours.

These factors will also determine the optimum stack height for efficient operation of the facility, with maximum height also being affected by the loader’s bucket reach. Oxygen is the number one enemy of good silage making and so, to ensure its access is controlled, a good quality 150mm micron thick polythene is essential. Choosing black or white polythene will pay dividends and better enable the farmer to keep temperatures in the stack below 30° Celsius, the point where the silage is over cooked and the food value can start to drop off rapidly.

Some things never change and old car tyres are still one of the best ways of ensuring the stack is kept properly wrapped and sealed and it’s always a good idea to lay baits for rats, mice and possums, making sure the bait is secure from other farm animals.