Glazing bars are the unsung heroes of any polycarbonate or glass roof, and choosing the wrong ones can be very costly.
We’ve spent decades developing and testing the best glazing bars so installers like you can know what they should use.
Read on below to discover the options…
What are glazing bars?
Glazing bars are the essential profiles used to join, secure and install all types of roof glazing, including polycarbonate, solid glazing and glass. Usually, glazing bars secure the roofing sheets to timber rafters but some glazing bar systems are also self-supporting.
In the trade, there is a host of names used for glazing bars including joining strips, joint bars, rails, H bars and junction profiles – just to name a few!
Choosing the correct glazing bars to suit your roofing type and roof structure is critical for the roof’s lifespan and therefore an important decision.
What glazing bars suit polycarbonate sheets?
All the glazing bars that Clear Amber manufactures suit multiwall and twinwall polycarbonate sheets, including Alukap-XR, Alukap-SS and Snapa glazing bar systems.
These ranges suit all thickness of polycarbonate, with the exception of the Snapa Span fix bars which only work with 10mm, 16mm and 25mm polycarbonate.
It is important to know that only the Alukap® aluminium glazing bars work with solid polycarbonate sheets.
What glazing bars work with glass?
Using appropriate glazing bars for glass is critical due to the high weight of glass compared to other roofing options, like polycarbonate.
Alukap-XR rafter supported and Alukap-SS Self supporting glazing bars are the best and correct bars to use when installing glass of all thicknesses.
We manufacture three main types of glazing bars. Click on the titles below to skip forward, if you wish:
Snapa PVC Glazing Bar
Starting at the most affordable option, we have the Snapa® glazing bars whichare the go-to budget option for joining polycarbonate sheets.
These bars are the lowest cost due to being made from PVC, a robust plastic resin.
Being made from plastic, they require full timber rafter support directly below which they are screwed into. Then the top cap simply snaps into the base.
This easy snap-fix installation process makes Snapa® super popular for installers or all skill levels, including DIYers.
Unlike any other system, Snapa® bars are the only PVC glazing bars produced with a proper gable and proper wall bar. These Gable bars have a simple two-part design (base and top) without any need for fiddley trims or side sections.
Snapa polycarbonate glazing bars are suitable for 10mm, 16mm and 25mm Axiome® polycarbonate sheet thicknesses. These are the budget choice of glazing bar for polycarbonate sheets.
PVC glazing bars are available in white which is the most popular and an excellent neutral colour. It is important never to purchase dark colours of PVC glazing bars, like black, brown, grey, as they fade very fast and go brittle.
If you are looking for more colour options or a stronger system then read on as our Alukap® aluminium glazing bars are the ones for you.
Pros: A low cost easy-install system for 10mm, 16mm and 25mm polycarbonate
Cons: There are longer-lasting more durable options that work with any thickness
Alukap XR Aluminium Rafter Bar
For a stronger glazing bar for rafters, you should choose the aluminium Alukap-XR bars. These are renowned with installers for their quality and durability.
A host of details, like the fact that they have a full cover cap to fully conceal fixings, all combine to create a visually stunning system.
Alukap-XR is an exceptional system for installers with a taste for quality and desire for longevity.
Alukap-XR glazing bars offer superb lifespan as we manufacture them from high-quality aluminium. Estimated lifespan of 20 years with many projects far exceeding that.
Although they seem more complicated than the PVC snap-fix glazing bars, these bars are equally easy to install with a simple screw down to the timber rafter. A robust easy install process.
All fixings are hidden and rubber gaskets included for maximum watertightness.
Looking for a bespoke colour to match your house style? Alukap-XR aluminium glazing bars are the choice for you being available in white and dark brown as standard plus any RAL colour!
Alukap-XR aluminium glazing bars work with any thickness of glazing, including Axgard® solid sheets and glass. A huge benefit giving you an unrestricted choice of roofing sheets.
Popular glazing choices include 16mm polycarbonate sheets, 24mm double glazing units and 6mm solid polycarbonate.
Order via Clear Amber Shop and you’ll receive timber fixings included for free with every bar ordered!
Pros: A durable stylish aluminium glazing bar system for all thicknesses and types of glazing.
Cons: Higher upfront cost than PVC glazing bars (although more cost effective long term).
Alukap-SS Self Supporting Bar
Remove the hassle and maintenance challenges of timber rafters by switching to Alukap-SS Self Supporting bars.
These glazing bars simply remove the need of having a timber frame by including beams as part of the bar.
With all components produced from aluminium, choosing Alukap-SS is choosing max lifespan.
Surprisingly, you can achieve incredible spans up to 6 metres, depending on the self-supporting profile used. Here is a guide of approximate spans for each profile:
- Alukap-SS High Span Bars – span up to 5.5* metres
- Alukap-SS Low Profile Bars – span up to 3.4* metres
- Alukap-SS Slimline Bars (for purlin roofs only) – span up to 1.75* metres
*Spanning is affected by a huge range of factors so please view the Alukap-SS installation guide for full details on span capabilities.
As with our Alukap-XR rafter supported system, the Alukap-SS self supporting glazing bars work with any thickness of glazing.
It also has fully concealed fixings and a range of innovative features. For example, Aluflow® aluminium guttering brackets simply clip into the Eaves beam to make installing a proper gutter straightforward.
Pros: A fully aluminium self supporting glazing bar system that removes the maintenance and eyesore of timber.
Cons: Slightly more advanced skills required if doing installation DIY.
What are the best glazing bars?
Ultimately, the best roof glazing bars depends on your budget and structure type, but Clear Amber has three excellent options for each scenario:
- Timber supported budget option: Snapa
- Rafter supported best option: Alukap-XR
- Self-supporting best option: Alukap-SS
So, whatever your budget there is an option for you!
| Snapa | Alukap-XR | Alukap-SS | |
| Lifespan | 10 years | 20+ years (ex timber rafters) | 20+ years |
| Colours | White | White, Brown, Any RAL colour | White, Brown, Any RAL colour |
| Works with | Axiome® Twinwall & Multiwall Polycarbonate | All polycarbonate and glass, any thickness | All polycarbonate and glass, any thickness |
Contact our live chat team if you still have any lingering questions and we’ll be sure to help. You can also view all our product reviews for a wide range of images of completed customer projects using all the different types of glazing bars.
