What are composite doors made of?
It’s a question that we receive on a regular basis about these leading home entrances, as unlike uPVC, aluminium or timber, the name doesn’t necessarily give it away.
The term composite means made up of several elements. When it comes to composite doors, these are a GRP outer skin (a tough, weather-resistant, glass reinforced plastic that resembles solid timber whilst standing up to knocks and scratches).
The centre of a composite door is either made up of a solid timber core (great for security), or a dense polyurethane foam section, chosen for elite thermal performance. You can choose either from Northwich Glass. Surrounding this core is a reinforced frame, usually uPVC reinforced by aluminium, designed to ensure the structural integrity of the door for decades to come, as well as supporting premium hardware and multi-point locks.
Whilst this may seem confusing, the benefits of such materials working in tandem are more cut and dried. With composite doors, you can look forward to lower energy bills, a higher degree of security, and a stylish exterior. We’ll explore them in more detail below.
In-depth: What are composite doors made of?
Composite doors are built using different materials, each chosen for its specific properties. Here’s a closer look at the construction.
GRP outer skin
The GRP (glass-reinforced plastic) skin forms the exterior surface.
Benefits:
- Resists dents, scratches, and fading
- Provides excellent weather resistance
- Mimics the look of wooden doors without the upkeep
- Adds rigidity to the composite door construction
Solid timber core
Some doors, like our Solidor range, feature a thick solid timber core, around 48 mm thick.
Benefits:
- Strong structural integrity and weighty feel
- Reliable screw retention for hardware, including lever handles and locks
- Supports excellent thermal insulation and warm thermal polyurethane foam alternatives in some models
- Traditional, premium timber door aesthetics
Insulating foam core
Other doors, such as Rockdoor (we install Rockdoor and Solidor), use a dense polyurethane foam core, which provides excellent energy efficiency.
Benefits:
- Keeps homes warmer by reducing heat loss in the winter, meaning lower bills
- Supports high-pressure reinforced frames
- Very low maintenance, unlike solid wood doors
- Helps meet current building regulations for insulation
Reinforced frame
Modern frames, made from uPVC reinforced with metal, ensuring structural integrity and long-lasting performance.
Benefits:
- Supports secure multi-point locking systems
- Adds rigidity to composite door construction
- Long-lasting and compliant with industry norms
What are the benefits of a composite door?
The combination of GRP, timber or foam cores, and reinforced frames delivers the ultimate modern front door. Here’s why homeowners choose them:
Energy efficiency
Doors with a solid timber core or warm thermal polyurethane foam provide excellent thermal efficiency, reducing heat loss and keeping energy bills down. Typical U values range from 1.4 W/m²K to as low as 0.9 W/m²K.
Security
High-security multi-point locks, reinforced frames, and sometimes bonded glazing give peace of mind and protect your home from intrusion.
Durability and weather resistance
Thanks to GRP skins and reinforced frames, composite doors resist knocks, rain, frost, and UV damage. Unlike wooden doors, they don’t warp or crack.
Noise reduction
The insulating foam core or solid timber core reduces external noise, providing a quieter home environment.
Low maintenance
Composite doors are low maintenance, saving money and effort over the years compared to solid wood doors or uPVC doors alone.
Wide range of styles
Available in a wide range of colours and woodgrain effects, including popular shades like Traffic Red, Chartwell Green, Anthracite Grey, Duck Egg Blue, and Golden Oak. You can even request a small colour sample before deciding.
Composite doors from Northwich Glass
We’re a trusted composite door supplier and installer, offering two main ranges:
- Solidor doors: Feature a thick solid timber core, replaceable glazed cassettes, and excellent thermal insulation.
- Rockdoor doors: Use a foam core, reinforced frame, and GRP skins for durability, security, and very low maintenance.
Colours and finishes:
- Classic: White, Cream, Golden Sand
- Woodgrain: Oak, Rosewood, Irish Oak, Golden Oak
- Contemporary: Anthracite Grey, Peacock Blue, Cobalt Blue, Duck Egg Blue
And so much more! You can see a few for yourself on our gallery.
Hardware and glazing:
- Multi-point locking systems
- Lever handles, letterplates, knockers, and spyholes in matching finishes
- Bonded or replaceable glazing options
Why choose Northwich Glass:
- Over 60 years of experience and genuine integrity
- FENSA accredited and Which? Trusted Trader
- 10-year guarantee on installations
- Friendly team providing great support and good prompt customer service
FAQs
What makes a composite door different from single material doors?
Composite doors combine GRP skins, solid timber or polyurethane foam cores, and reinforced frames, unlike single material doors such as aluminium, uPVC doors or wooden doors.
How long do composite doors last?
With proper care, composite doors can last 35 years or more, making them an excellent long-term investment.
Can I get a composite door in my favourite colour?
Yes! We offer a wide range of colours and woodgrain effects, and you can view a small colour sample to find your favourite door for your home.
Can I see a composite door before buying?
Yes! At Northwich Glass, we understand the importance of seeing a new door in person before making a high pressure decision like this. Our showroom features display boards, and our friendly staff will be there to answer any questions you may have, giving you the confidence to choose a door that matches your home and personal taste.
How long does it take to install a composite door?
Installation times vary depending on your home, but our experienced installation company team pays a lot of attention to every detail. From measuring to fitting, we ensure your door meets the correct building regulations and provides the level of security features you need.
The vast majority are completed within a day.
Who are Northwich Glass?
Founded in 1959, Northwich Glass is an honest local company with over 60 years of experience in windows, doors, and conservatory roofs across Cheshire.
- Accreditations: FENSA, Which? Trusted Trader
- Showroom: Explore our wide range of styles and colour options in Northwich
- Expert team: Our fitters and designers provide great support, customer care, and advice for your project
For a no-obligation quote on a composite door, feel free to contact us or fill in our simple online form! We’ll help you find a quality product that perfectly suits your home, style, and budget.
