Posted by s.shabbir · June 5th 2025
Established in 1997, Rockdoor was known as the original composite door. All these years later, we still firmly believe we make the UK’s strongest composite doors.
When you look at a Rockdoor, you see a stylish, secure entrance door built to suit your home. But what you might not see, at least not at first glance, is what’s inside. And that’s where the real strength lies.
Every Rockdoor is built around a high-grade aluminium box section that forms the inner core of the door. This solid aluminium framework is a key component that makes our doors reliable, strong, and long-lasting. It’s something we’ve been refining for years—and today, it’s stronger than ever.
In fact, the aluminium reinforcing we use now is 50% stronger than when we first introduced it. That’s more than just a small tweak, it’s a major leap in our composite door manufacturing and a clear sign of our commitment to continuous quality improvement. We use aluminium not just for its incredible strength, but because it’s completely resistant to water and moisture, ensuring long-term performance.
Aluminium Reinforced Composite Doors
Rockdoors feature a 10mm Aluminium box section reinforcing that runs the full perimeter of the door itself, providing total perimeter security. Aluminium reinforcing is mitred into each section, creating a continuous 360° ring of security to ensure the door cannot bow, bend or deflect.
The benefits of aluminium reinforcing go beyond 360° structural strength and prevent door movement; it also provides a solid foundation for fitting essential door hardware.
Key door components like 3D hinges, Winkhaus lock straps, handles, and cylinders are fixed directly into the aluminium frame, improving screw retention and, ultimately, enhancing the door’s overall security.
So, if you are looking for a strong and secure composite door that is unaffected by moisture, then look no further than Rockdoor.
Explore Our Door Styles
No Bow Guarantee
All of our composite doors are carefully manufactured with a new internal aluminium box section, allowing us to offer an industry-leading 3mm No Bow Guarantee on every door. Hot summers, freezing winters, heavy rain, none of it fazes our doors.
Since this improvement was introduced, we’ve produced almost 200,000 doors with this reinforced design, and our quality stats back it up: bowing issues are a thing of the past.
Every Rockdoor composite door is built with precision, tested with care, and continually evolving to meet the highest standards to give you peace of mind.
It’s the result of years of innovation, smart design, and a deep commitment to building doors that are as strong as they are stylish.
No Timber, No Compromise
You won’t find any timber in a Rockdoor core. And that’s by design. While wood may seem like a solid choice, it doesn’t stand up well to temperature and moisture changes. It can swell, shrink or warp, leading to long-term problems with performance and security.
Other composite doors either use timber to reinforce their doors around the perimeter of the sash or choose timber as the main inner core of the door itself. Neither of these options was chosen by us when designing our door as they didn’t offer the strength we needed, whilst also being susceptible to water ingress.
By building our doors without timber and reinforcing them with aluminium, we ensure every Rockdoor performs consistently with excellent thermal performance, no matter what the weather throws at it.
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