Secret Fix Copings Your Complete Guide to Specification | HJA Fabrications

Secret Fix Copings: Your Complete Guide to Specification

Wall copings are a fundamental part of any building structure, providing a watertight protective barrier for parapet walls and roofs. Copings don’t just cap the top of a wall, but come down both sides, encasing it and adding extra protection all the way around. 

But when it comes to standard aluminium copings, they do often fall short of the desired outcome specifiers and installers want when choosing a coping system. That’s where Secret Fix copings come in.

A secret, or hidden, fixing coping provides benefits more than just a cleaner line and therefore better aesthetic. They also offer an engineered solution to a standard fixed coping. Secret fix copings are themselves not bolted to the perimeter or parapet wall, but to a bracket which is.

This provides a multitude of benefits ranging from improved weatherproofing, higher wind-loading capacity, more secure mounting, and a much speedier installation.

We must acknowledge that we are an aluminium fabrications company, and do specialise in Secret Fix copings, so are slightly biased. But for this article, we will put favouritism to the side and just give you the plain and simple advantages and need-to-knows for specifying a Secret Fix system on your next architectural project.

In this guide we will cover everything you need to know for the specification and installation of secret fix copings:

HJA Fabrications provides high-quality Secret Fix Aluminium Coping systems available to specification.

Manufactured to a variety of widths and shapes, as well as wind tested to 144 mph, you can ensure ultimate performance and longevity, whatever the elements throw at you. Polyester powder coating is available from standard RAL & BS Colours to Metallics, meaning you can create a unique aesthetic, no matter what the application may be.

Download our guide | Aluminium Copings

What are Secret Fix Copings

Aluminium copings are an architectural element that is fixed to the top of a parapet wall, the most vulnerable part of a roofing structure, in order to make them watertight.

Copings direct water off the top surface, either due to a pitched surface or through projecting the water away from the wall due to the overhang of the coping.

Aluminium copings are a popular style of coping due to their durability, strength and fire-rating. Moreover, aluminium is a lightweight and corrosion-resistant metal, meaning not only is it easier to manufacture but it also looks good for longer than other coping material options, i.e. lead, copper, or stone.

Aluminium fabricated copings are suited for a wide variety of applications and suit most projects. But what about projects which require a clean finish?

For this, Secret Fix aluminium copings are the only option.

As highlighted in the name, secret fix copings offer a hidden fixing system, in contrast to standard fixed copings.

A secret fix coping uses an engineered bracket to attach to a parapet wall. The coping is then clip-fixed to the extruded bracket which provides a secure fixing. This means the finished coping has a clean aesthetic whilst also benefiting from having no holes going straight through it.

The benefits this ideal fixing method provides are numerous:

  • Coping can handle expansion and contraction
  • Will resist the strongest gusts of wind
  • No detriment to the appearance of the coping, (in fact, it improves appearance.)
  • Is installed quickly and easily

HJA’s Secret Fix Coping System

Our Secret Fix copings are proprietary, but we can highlight some of the key benefits it provides.

HJA’s Secret Fix copings are protected against water penetration due to polymer gaskets that are integrated into the brackets. These also prevent wind rattle, along with anti-rattle foam.

As for wind resistance, the HJA Secret Fix aluminium coping system has been independently wind-tested to 144mph. The engineered design, including the extruded brackets’ exclusive design, creates superior wind-loading.

The HJA Secret Fix copings offer an attractive, low maintenance coping system that is simple to install yet both rigid and secure. The out of sight coping fixings provide a smooth, fastener-free appearance that any architect would desire.

Coping Rain Shot

Benefits of Secret Fix Coping

Other than the main advantages hidden fix copings offer which I have highlighted above, there are also numerous other benefits they provide, to specifiers, installers and building owners.

-No Deformation

Firstly, unlike fixed copings, secret fix copings do not risk being deformed in high temperatures. Without bolts going through the coping, the metal is free to expand and contract on hot days. There is no pressure on the system, and therefore there is also no risk of it bowing under pressure, or even in worst-case scenarios, snapping the fixings off.

-No Need for Waterproofing Sealants

Secondly, secret fix copings offer a much higher level of finish. Not only due to the hidden fixing but also due to the fact there is no need for waterproofing sealants, which are often unsightly e.g. mastic or bitumen. Without the need to seal up the fixing holes which go straight through the coping in standard systems, secret fix copings provide superior weather protection.

Also, you can rest easy knowing your secret fix coping has longer-lasting weather protection, since even sealants degrade over time due to UV exposure, meaning water often creeps under the coping and into the brick below in standard fixed coping systems.

Failed fixed copings are often the cause of damp, rot, leaks, and mould in buildings. The lack of protection against water ingress can also then develop into freeze-thaw damage within the bricks themselves, causes rendering to crack and fall off, as well as cavity insulation to be damaged.

With a secret fix coping system you can prevent water ingress and the catastrophic issues that can create.

-Easier and Faster Installation

With a standard coping, the installation process is considerably time-consuming. First, you must bolt plywood and then a bracket into the wall. Then you go along the wall checking it is level, adding any shims or packers to ensure the coping sits flat. Finally, installers go along the wall bolting the coping in place, including making the holes.

With a secret fix system, installers make all the adjustments on the bracket, again ensuring its level, and then all they need to do is go along the wall and snap the secret fix copings onto the brackets. You can even cut the copings down in length easily on-site. The process is much faster and is by far the preferred method of coping when it comes to installation.

-Value for Money

Secret fix copings systems are more expensive than fixed coping ones due to the fact it is an engineered solution.

Although they may cost slightly more than regular fit fixings, this money can be saved in labour costs, as less time is needed to install and complete coping projects.

Moreover, the catastrophic issues that water ingress can introduce can mean it pays to invest more upfront to protect against them in the future.

-Higher Spec Standard

With all fixings hidden out of view, secret fix copings offer a much higher standard of finish. When you see a standard coping next to a secret fix one, it’s clear they are much more attractive.

Secret fix aluminium copings are a popular choice for many architects and designers due to this clean aesthetic. They are a great choice for many roofing and building projects due to the fact they improve the look of any roof terrace, sky bar, or parapet wall.

Choosing a hidden fix coping means choosing a good looking system that has clean lines and doesn’t detract from the rest of the high-quality specifications.

-Anti-Wind Rattle

With standard fixed aluminium copings, you may often hear building residents or tenants complain of wind-rattle on stormy nights. Due to the lightweight and proportions of aluminium, copings fabricated from it do tend to get the wind caught beneath them and make an unpleasant rattling noise.

The mechanical fasteners of fixed copings will always offer at least a slight amount of play. When under pressure from wind, that play will result in wear and tear that will increase the rattling problem. This can even lead to the failure of aluminium copings even remaining in place.

Secret Fix copings use an extruded bracket as the fixing to the parapet wall. Because of this, they prevent wind-rattle. If manufactured with added anti-rattle foam under the bracket you can further deaden any sound of rattle. This gives your residents peace of mind, especially in extreme weather.

Secret fix coping site installation on MOD facility

Why Should You Specify Secret Fix Copings

When it comes to specifying Secret Fix copings, the main reason is to avoid the many drawbacks of fixed aluminium copings. Fixed copings often fail after years of expanding and contracting throughout hot days and cool nights. When constrained, the pressure causes it to buckle and bow in the middle, as well as deform fasteners.

Secondly, the fixings do require holes to be drilled through the top of the coping which is an entry point for the water we are trying to keep out. Over time, sealants can fail, leading to leaks, dampness, and mould, as well as cracked wall rendering and damaged insulation.

These two issues with fixing copings in the standard way is what can be costly and impractical.

But the main reason why architects and construction companies will specify secret fix copings is down to its namesake function – it provides hidden fixings.

Copings are an integral, and visible, element of a building’s structure. Whether on a roof or parapet wall, copings are part of residents’ vistas when they look to neighbouring buildings or from their balcony to another’s.

Let’s face it, roofs are now often deliberately designed into architectural projects and we have seen a massive increase in residents having access to their roof as well as living roof gardens and rooftop bars.

To ensure the coping is an attractive addition to a building, using a secret fixing system will guarantee clean lines and a great finish.

Design Considerations for Secret Fix Copings

Aluminium secret fix copings can provide a superior aesthetic to any roofing job whilst also playing an integral role in waterproofing a parapet wall. But when considering the design, it’s more than just having ‘hidden fixings’ that secret fix copings provide.

As copings don’t just cap the top of a wall but come down both sides – they are a visible part of the building. So whether on roof gardens and balconies, or just basic roofs, copings must deliver an attractive finish.


Efflorescence is the white stains/drips that you can see on aged brick walls. It occurs when water leaves behind salt deposits on the masonry surface.

Wall copings protect against this as the projection of the coping over the edge of the wall allows water to be ‘thrown’ away from its surface. This prevents efflorescence and therefore protects the building from unsightly marks.

However, secret fix copings go one step further. Due to the central bracket, used to fix the coping, you can gain added water run-off capabilities. Coping manufacturers can extrude the bracket to include a channel for this very purpose, further protecting the building from water staining.

-Damaged Rendering

The superior waterproofing of secret fix copings, due to there not being any holes drilled through the surface of the coping, means you can better protect the building from the issues that water ingress creates.

One of the most expensive issues being cracked rendering. When water seeps into the building structure and through the bricks, freeze-thaw damage can occur when the water expands and contracts throughout the day and night.

This freeze-thaw creates awful water damage to a building structure and as more rendering cracks off, more water can seep in, get trapped, and freeze again.

Secret fix copings are a great remedy to this vicious cycle and will extend the life of any rendered wall.

By preventing watermarks and cracked rendering on the outer walls of a building, you can enhance the look of your development. Specifying secret fix copings in your project ensures you will achieve the high-quality visual you are aiming for, for years to come.

Download our guide | Aluminium Copings

Installation Considerations for Secret Fix Copings

Whether you are an architect or a construction company, considering the installation of your upcoming project is important, especially when finding the perfect coping solution. Are secret fix copings easier and simpler to install than standard copings?

What other things will you need to consider when it comes to choosing a coping solution for your next project?

-Installation Time

With a Secret Fix system, the installation process is considerably faster and simpler. Installers make adjustments on the Secret Fix bracket to ensure its level, and then simply go along the wall and snap the secret fix copings onto the brackets.

This clip-fixing process is a much more efficient process in comparison to the standard fixing process.

If you want to check out a video of how HJA’s Secret Fix copings are installed, click here.

-Lead Time

If specifying a Secret Fix coping you will need to consider the fact that they do require a longer lead time. This is due to the manufacture of the bracket which must be made on top of the fabrication of the actual coping itself.

However, due to all the benefits Secret Fix copings provide, ranging from wind-rattle prevention and a more attractive look to being a superior waterproofing solution and a stronger one at that, specifying Secret Fix copings is worth the longer time it takes to manufacture.

-Bi-Metallic Corrosion

Another important consideration for specifying metal copings is the risk that can run due to bi-metallic corrosion. This form of corrosion occurs due to the placing together of two different metals, which means when installing aluminium copings, the bracket and other installation accessories must also aluminium too (not galvanised steel).

Bi-metallic corrosion can be exacerbated by salt and moisture in coastal areas.

Applications for Secret Fix Copings

-Parapet Walls

Practically every modern flat-roofed building incorporates a parapet wall. In addition, many older buildings – particularly terraces – have parapet walls separating the roofs of adjoining properties.

A parapet wall is an extension of the exterior or dividing wall that extends up above the roof. These parapets are generally horizontal, unlike those often used between terraced properties. On these, the wall is often pitched at the same angle as the roof itself.

Water naturally runs off a pitched parapet wall. Horizontal walls need an angled surface to achieve the same effect. In both cases, the coping directs water away rather than letting it rest on, and penetrate the wall itself.

However, there are also other applications where secret fix copings are a great option

  • Perimeter walls
  • Curtain walls
  • Clean outline for roof edging
  • Balconies
  • Roof gardens/access
  • Skybars/rooftop bars

For projects where the roof of a building is a highlight to the project and is being specifically designed as part of the building’s assets, then an attractive coping system is essential.

Roof gardens, living roofs, rooftop bars and others are becoming more and more popular as people aim to make the most of the space they have.

HJA Fabrications Bespoke Aluminium Fabrications

What to Look out for with Secret Fix Copings

Depending on the application of your coping system, specific features may be of more importance than others when specifying your Secret Fix solution.

You also must take into account the weather circumstances at your project site – wind, rain, sunlight, and temperature range can all make an impact on the efficacy and longevity of a coping system.

With wind, you must consider the strength of it at the height of the roof. Gusts of wind in the UK have been recorded as high as 150mph. This is a particular problem in exposed locations, especially along the coast.

Knowledge of the maximum peak wind speeds to be expected informs how the coping should be fixed to the wall. A strong coping attachment must be considered – HJA Secret Fix coping is wind-tested to 144mph and provides superior wind resistance than any other coping on the market.

Rain is also something to consider, especially as the point of the coping is to protect against water. You should consider if water will pool at the roof and whether an incline should be used to divert it (a weathered coping has a slope for this purpose).

Sunlight and variation in temperature are particular challenges when using metal copings. Thermal expansion and contraction must be factored into both the fixing methods used and the joint design. With a Secret Fix coping, one of the key advantages it offers in comparison to a fixed coping is the ability for thermal expansion to take place without putting pressure on the system and risking the fixing failing.

Download our guide | Aluminium Copings

HJA Fabrications: Specialists in Aluminium Coping Systems

HJA’s Secret Fix copings protect against water penetration due to advanced polymer gaskets that are integrated into the proprietary brackets. Anti-rattle foam, combined with the highly engineered bracket, prevent wind-rattle. 

As for wind resistance, the HJA Secret Fix aluminium coping system has been independently wind-tested to 144mph.

Due to the unique way the copings clip into place, they are also much faster to install than any other coping fix system available on the market. This allows construction workers to fit more copings in a shorter period of time, accelerating productivity and efficiency on-site.

The HJA Secret Fix Coping System offers an attractive, low maintenance coping solution that is simple to install yet both rigid and secure. Last, but by no means least, the hidden fixings provide a smooth, clean, fastener-free aesthetic that adds a perfect finishing touch that any architect would desire. 

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