all about rockdoors

What are rockdoors?

Rockdoors are a specific brand of composite doors that are built, tested and manufactured to much higher standards than most other composite doors, excelling in thermal insulation, sound insulation and security. They are considered a top premium composite door. The best you can get.

Read below to find out why a Rockdoor is one of the best composite doors on the market and why if budget allows Rockdoors should be top of your list.


Below is a quick overview of a Rockdoors technical specification on paper.

- 3mm UPVc high impact and resistant internal and external skin, protected against discolouring, heat and pets.
- High Density Polyurethane core
- 10mm thick aluminium box section that runs the perimeter of the door
- 3 star Avocet ATK cylinder
- 2x 25mm throw brass hooks coated in nickel with shootbolt
- 3D heavy duty butt hinges
- 50mm thick door sash
- S-Glaze technology
- Secured by design accredited
- Full length steel keep that runs the length of the outer frame

high impact skins

Rockdoors high impact skins are made from compressed uPVC. It is 3mm thick and extremely strong. They feature heat shield technology to help reflect the rays from the sun. The skin’s are not painted, and if scratched deep enough they show white underneath the colour, but due to their strength they are very durable and very difficult to scratch, even by pets. 

The Rockdoor skins come in flat sheets which are moulded into the desired shape by using heat and an aluminium template engraved with all the grained details of the door to be made. The grain effect gives a realistic effect of having a wooden door and is one of the best looking and most durable skins I have ever come across. The grain is not too much and doesn’t give the look of a GRP skin where the grain far too strong. Touch up pens are available and are a perfect colour match should the door ever be damaged or scratched.

Locking cylinders

All Rockdoors come with a 3 star cylinder as standard. This cylinder is the ATK Series manufactured by Avocet and comes in silver or gold depending on what colour furniture you have (black furniture comes with a silver cylinder). The Rockdoor cylinder has the usual features you would expect on one of the most secure locks you can get, such as:

- Anti-snap
- Anti-pick
- Anti-bump
- Anti-drill

This 3 star accreditation ensures you have the very best lock available to protect your home and ensures that the lock can never be a weak point. All Rockdoors come with 3 keys as standard, each with their own branded purple Rockdoor key, blank Rockdoor keys are also available should you wish to get more cut.

Sometimes customers do wish to change the lock for either an Ultion or Avocet ABS or because they want it to be keyed alike with their other doors etc.

The specification of the Rockdoor cylinder is:

- 80mm total length
- 40mm / 40mm
- Equal split

Locking Mechanisms

The standard Rockdoor locking mechanism specification is as follows:

- 2x tapered 25mm throw brass hooks, nickel coated
- 1x centre shootbolt
- Steel full length keep

The 25mm throw brass hooks are designed for mainly one thing, and that is to engage into the steel keeps on the outer frame and never separate. They are a serious locking mechanism that ensures forced entry is virtually impossible.

Unlike most other doors which use small sectional keeps, the real strength and security on a Rockdoor not only comes from the huge hooks, but it also comes from the one piece steel keep that runs the full length of the outer frame. We generally put 122mm or 142mm screws to fix a door, but other installers may use something different. You have 4 screws in total that go through the steel keep, through the frame, and directly into the brick making it unbelievably secure when its locked.

This steel keep enables any brute force applied to be spread over a much larger area rather than targeting the force all on one hook. We have only ever been to one attempted break-in on a Rockdoor in which sledgehammers were used, the door was hit several times over before they fled due to the amount of noise they made. The Rockdoor was virtually untouched.

Rockdoor offer the option of a 4 hook lock which in my opinion is overkill but it’s there if you want the extra piece of mind. The hooks are also tapered which are designed to bite into the steel keeps and squeeze the door onto the seal, further improving sound and thermal insulation, especially when it can be very windy.

S-Glaze Technology

The problem with glazing cassettes, even though they have come a long way since first introduced, they still have drawbacks. Some of the drawbacks can be:

- Discolouration
- Draughts
- Limited flexibility
- Water ingress
- Sound insulation
- Thermal insulation
- Security
- Aesthetics

Rockdoor realised this and decided to manufacturer their doors differently using what they call S-Glaze technology. This is a unique way to solve the issues you can face from glazing cassettes with just 1 potential disadvantage. As Rockdoor retain the same inner reinforcing on every door no matter the width or height, they can inject a high density polyurethane foam that pushes any air out inside the door, replacing it with a thermal and sound insulating foam instead. This ensures that not a single part of the door has air inside and is completely sealed throughout. This means the glass in a Rockdoor is built into the door and cannot be removed or changed, at all.

Rockdoors S-glaze technology has many advantages over a glazing cassette including:

- Better sound insulation
- Better thermal insulation
- Keeps water out
- Enhances security
- Enhances the reliability of the double glazing units
- Improves the aesthetics of the door.

The only disadvantage is that as the glass is built in, you are unable to change the glass unless you replace the whole door slab, some people get put off by this but I’ve fitted over 900 Rockdoors and never had 1 glass unit fail or mist up.

Rockdoors Core

Rockdoors core is made from a very high density foam called polyurethane. It sounds quite weak but when it is sandwiched between the two high impact 3mm skins, it is unbelievably strong. The polyurethane foam has quite a few advantages over other materials.

- Better thermal insulation
- Does not soak up water
- Better sound insulation
- Very strong

The polyurethane foam is injected into the Rockdoor when it is manufactured and small air holes are drilled into the sash to ensure the foam can quickly expand and fill all the voids in the door, giving you good sound and thermal insulation, especially around the glass units.

We get asked sometimes regarding the foam core ‘what if someone cuts through it?’. Well due to the 3mm skin, a stanley knife just isn’t going to cut it! You would need a power tool but this is so so rare people get broken into like this and typically throwing a brick through a window would be just as effective and much easier. Rockdoor offer the option of having steel mesh inside the door which reinforces the foam and the door even further much like they way steel reinforces concrete, this would prevent anyone potentially trying to cut their way through as it would take a very, very long time.

Next Generation

All Rockdoors manufactured from June 1st 2019 have an aluminium box section around the edge of the door. Previously this was carbon fibre which although strong, had some disadvantages. Rockdoors new 10mm aluminium box section removes the disadvantages the carbon fibre reinforcing had, whilst improving strength.

Regardless of how short or tall your door is, the aluminium box section is cut to millimetre precision and mitred into the 4 corners of the door slab, so the entire edge of the door is reinforced giving immense strength. The hinges and locking mechanisms are fixed directly into this box section which ensures they remain absolutely solid and never separate, even under extreme pressures.

It was in development for a long time and to properly test it for strength, reliability, durability and security, Rockdoor commissioned their own purpose-built climate environmental testing lab, which is a steel rig that is temperate controlled so it can be extremely hot one side and extremely cold the other to mimic a Rockdoor in the sun on a summers day and vice versa. Not only that but their new rig can mimic natural climate changes, such as slow temperate increases and decreases on each side of the door during the course of a day, continuously over a long period of time.

All Rockdoors are made-to-measure, that means each door is built from the ground up with materials that are cut to size, designed and built to your bespoke door specification.


Rockdoors are designed to be as maintenance free as possible, however there are a few things you can do to keep your door looking brand new and operating like the day it was fitted. There are only two things to really maintain on a Rockdoor:

1) Like most composite doors, dirt, dust and debris gathers in the threshold of your Rockdoor over time, wether that is a low aluminium threshold, slim PVC or full PVC. I would recommend hoovering and then wiping the threshold and outer frame where the lock keep and hinges are to remove any debris. If you have a low aluminium threshold on your door, you can use some silicone spray to spray inside the threshold and then open and close the door a couple of times to treat the rubbers on the bottom of the door. We recommend doing this once every 2-3 months.

2) Lubricate the hooks. Generally WD-40 is sufficient but WD-40 attracts dirt, for this reason I recommend the 3-in-1 white lithium grease, you can buy this at most places including Halfords. Open the door, lift the hooks and spray a generous amount around the hooks, latch and the shootbolt of your Rockdoor. Operate the hooks while the door is open several times to work the grease in, re-apply some more grease and wipe the excess from the side of the door with some tissue. We recommend doing this once every 6 months.

Do not spray anything in or around the cylinder, we recommend to leave this alone but if you do find it needs something, you must ONLY put graphite powder or lubricant inside it.

How to clean a rockdoor?

Rockdoors are very easy to clean. The following methods are recommended for cleaning your Rockdoor:

- Warm soapy water with a soft sponge or microfibre cloth to clean the door, glass and frame.
- Mild non abrasive window cleaner and microfibre cloth to clean the door, glass and frame.

If you have a white frame, you can buy some solvent or PVC cleaner to clean that internally and externally.

If it is a coloured frame, please use the mild window cleaner or soapy water. Should you have any bad contaminants or marks on your Rockdoor door slab and it is white, you can use solvent or PVC cleaner but be cautious with it and use in little quantities on your Rockdoor.

extra links and information

If you would like to read more about Rockdoors, you can view this article Who are Rockdoor?

If you would like to see the range of Rockdoors, you can view our Rockdoor Range

As one of the UK’s largest independent Rockdoor installer, we also offer Rockdoor French Doors and Rockdoor Stable Doors which offer the same security of a normal Rockdoor.


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