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Composite doors are an increasingly popular entrance door choice for UK homeowners. For double glazing installers this means that they are a must-have product to add to their catalogue. If you’re a trade installer and you’re looking for the best composite doors to offer to your customers, you may have found it difficult to choose from the various composite doors out there.

To help you to make a fully informed decision, let’s take a look at two of the top composite door manufacturers in the UK today.

Rockdoor composite doors are the pinnacle of composite door technology. They combine robust security and excellent levels of energy efficiency with a choice of stylish aesthetic finishes to perfectly complement any style of home.

When you choose Rockdoor composite doors, you can offer your customers:

  • A++ energy efficiency rating
  • 44mm or 50mm door sash thickness
  • Reinforced core made from aluminium or carbon fibre
  • High security multi-point locking systems
  • 10-year product guarantee
  • A wide range of styles, colours, and glazing options

At Double Glazing, we have supplied thousands of Rockdoor composite doors to our trade customers. We have received excellent feedback from the end user on the superior quality of the product and also from the installer on how popular they are with homeowners and how easy they are to install.


Door-Stop composite doors are available as GRP composite doors, FD30 fire doors, and solid core doors. They are a high performing entrance door suitable for a range of residential and commercial applications.

Door-Stop composite doors are:

  • Fitted with Secured by Design accredited locks
  • Available in a selection of colours with wood grain effect finishes
  • Available with a Part M compliant low threshold
  • Reglazable in case of accident

In our opinion Door-Stop composite doors cannot compete with the performance levels of Rockdoor. Door-Stop doors are secure, stylish, and provide excellent levels of thermal efficiency but come in second place when compared to Rockdoor.

How is a Rockdoor so much stronger than competitor doors?

All Rockdoors feature S-Glaze technology (Security Glazing) which is when the glass is manufactured as part of the door itself and locked in for life, rather than being clipped in by beads as an afterthought. This ensures exceptional thermal efficiency, but crucially it also means the glass can’t be forcibly removed by burglars as had happened to the neighbours.

Ultimate Rockdoors also feature Carbon Fibre reinforcement which strengthens the door even further, unlike other composite doors that are cut down and consequently weakened.

So whilst you may think a composite door is just that, there is actually much more to deciding which door should be the one to protect you and your family. 

Composite doors are especially advantageous over wooden and standard UPVC doors, in terms of security, durability and energy efficiency. Each individually crafted Rockdoor composite door features a state of the art multi point locking system for maximum security peace of mind. The outer shell of a composite door remains stable throughout seasonal temperature changes, unlike a wooden door which shrinks and expands in hot and cold weather. A composite door therefore retains its strength as the materials are not weakened by temperature related contraction or expansion or the need to force an expanding wooden door which is sticking. With far greater insulation than a timber front door, back door or stable door, composite doors offer significant energy cost savings and a lower carbon footprint!

Rock door were one of the first composite door manufacturers in the UK and our experience has lead to our reputation for outstanding quality front doors, back doors, stable doors and French Doors. Choose a composite door from Rock door and enjoy the ultimate combination of modern technology, functionality and reliability, with the timeless charm and style of a traditional timber door.