PVC-U inner frame
The hidden hero that plays a vital role in energy efficiency, strength, and overall door performance.
A CLOSER LOOK SERIES
PVC-U INNER FRAME
Following on from our previous topics in this series, where we explored the benefits of aluminium reinforcing and the leading edge, now we’re continuing our ‘A Closer Look’ series with an equally important, yet often unseen, key component: PVC-U inner frame, the hidden hero that plays a vital role in energy efficiency, strength, and overall door performance.
WHY DO WE USE A PVC-U INNER FRAME?
Unlike timber frames used by many other manufacturers, our rigid PVC-U inner frame is built to last. It won’t absorb moisture, rot, or warp over time – ensuring long-term stability and strength.
Made to measure for every door, it’s completely resistant to British weather, highly thermally efficient, and designed to complement the overall structural integrity of the Rockdoor.
It’s one of the key components that make Rockdoor the most reliable and secure composite door on the market. Take a look below to see why it plays such a vital role in every Rockdoor we make.
MADE TO MEASURE, NOT CUT TO FIT
Every Rockdoor is made to size, rather than being trimmed down from a blank and cut to fit. This allows us to maximise the security of our doors by using a welded PVC-U inner frame, reinforced with an aluminium box section that runs around the full circumference of the door. This means that, no matter the door size, the level of security is never compromised.
IMPERVIOUS TO BRITISH WEATHER
By using PVC-U instead of timber for our inner frames, whether as a sash material or reinforcement, we eliminate the risk of water absorption and swelling that can compromise a door over time. Unlike wood, PVC-U is completely impervious to moisture, making it ideally suited to withstand the challenges of British weather. This ensures long-term durability and reliability, meaning you won’t face call-backs due to water damage affecting a customer’s door.
THERMALLY EFFICIENT
As you would expect, PVC-U performs exceptionally well when compared to timber, meaning the energy ratings of our doors are industry-leading.
LEADING EDGE INTERGRATION
The PVC-U inner frame used within a Rockdoor is completely unique, as it has been designed to feature a leading edge on the vertical lock side of the door to improve performance. Although only a small feature, it makes a big difference to the experience of opening and closing a Rockdoor for a homeowner.
EXPLORE THE FULL CLOSER LOOK SERIES
SERIES 1
ALUMINIUM REINFORCING
Aluminium Reinforcing explained – what it is and why it matters
SERIES 2
LEADING EDGE
Discover why a Rockdoor shuts so smoothly.
SERIES 3
PVC-U INNER FRAME
The hidden hero who plays a vital role in Rockdoor.
SERIES 4
S-GLAZE TECHNOLOGY
Discover one of our most significant innovations.
SERIES 5
PREMIUM QUALITY HINGES
Discover why these hinges have been on every Rockdoor for almost 30 years.
SERIES 6
GASKETS
Learn how gaskets influence door perception.
SERIES 7
LOCKING MECHANISMS
Discover our tried, tested & trusted locking systems.
SERIES 8
STEEL MESH REINFORCING
The integrated security enhancement for Rockdoor.
SERIES 9
3-STAR CYLINDER
Learn about the 3-Star Diamond Sold Secure cylinder.
SERIES 10
HERITAGE PLUS LOCKS
Learn how our locks provide advanced multi-point technology
SERIES 11
UNIQUE DOOR STYLES
Discover door styles that make Rockdoor unique.
SERIES 12
ROCKDOOR STABLE DOORS
Reimagined through the years with modern engineering.
SERIES 13
ROCKDOOR FRENCH DOORS
Learn how French Doors brighten homes with elegance.
SERIES 14
ROCKDOOR DOUBLE DOORS
See why homeowners choose Double Doors for versatility & security.
SERIES 15
SMALL DETAILS, BIG IMPACT
Grub screws, switch latches & viewing clips.
Latest News
30 Years of Innovation
For almost 30 years, we’ve been redefining what a door can be. From signature styles and striking glass designs to pioneering construction and unmatched security, our innovations have earned the trust of more than one million homeowners throughout the UK.
Unique Doors
Every Rockdoor is uniquely made to reflect your personal taste, not just for how it looks, but for how it feels the moment you step through.
Customised Glass
With Rockdoor, each glazing design is crafted individually to strike the perfect balance of light, privacy, and personality for your home.
Standout Colours
Make an unforgettable impression with Rockdoor’s carefully curated colour range, designed to complement any style and last for years.
Highly Secure
Rockdoors are made to measure, never cut to fit, and with a reinforced inner frame, precision engineering, and multi-point locking systems, they are guaranteed to protect what matters most.
Warm & Cosy
There’s nothing like walking into a warm, cosy home. A Rockdoor helps make that welcome a little more comforting, every day — without you even thinking about it.
Unique Doors
Every Rockdoor is uniquely made to reflect your personal taste, not just for how it looks, but for how it feels the moment you step through.
Customised Glass
With Rockdoor, each glazing design is crafted individually to strike the perfect balance of light, privacy, and personality for your home.
Standout Colours
Make an unforgettable impression with Rockdoor’s carefully curated colour range, designed to complement any style and last for years.
Highly Secure
Rockdoors are made to measure, never cut to fit, and with a reinforced inner frame, precision engineering, and multi-point locking systems, they are guaranteed to protect what matters most.
Warm & Cosy
There’s nothing like walking into a warm, cosy home. A Rockdoor helps make that welcome a little more comforting, every day — without you even thinking about it.
Trusted Local Installers
Our wide network of 200+ Rockdoor Trusted Installers will help you choose your perfect door, carry out a hassle-free survey, provide you with an estimate and help plan your installation.
Design your dream door with the Rockdoor 3D Door Designer.
Choose unique styles, colours, and glass, then visualise on your home.
We are different.
We are Rockdoor.
Rockdoor stands in a league of its own because it’s engineered as a complete security and performance system. Every Rockdoor is built to order—crafted to look exceptional and last a lifetime. The result is a Rockdoor offering outstanding strength, efficiency, and long-lasting reliability, paired with style to suit any home.
