Frequently Asked Questions
The British Standard Code of Practice BS5516 For The Design And Installation Of Sloped And Vertical Patent Glazing states that 15° is the minimum pitch for roofglazing to ensure it provides an adequate pitch for drainage and so VITRAL roof glazing company comply and use this as our minimum pitch for our A74, VRS and GTS systems.
With all roofglazing systems a shallow pitch could allow water to collect on the glass or structure which is unattractive and if the British Standard feels that sloped glazing should have a minimum pitch of 15° to ensure if performs then it should be adhered to.
The exception to this is our Vitral Skyvision flat rooflight range that is installed between 4° and 15°.
VITRAL has recently been approved for use in Montgomery Primary School in Devon. VITRAL worked with the thermal energy consultant WARM to ensure that we meet the performance required in terms of air tightness and thermal performance.
This project also includes Natural Ventilation through the rooflight to assist in the cooling of the building as well as encouraging solar gain to make use of this natural heating resource.
Overall, on PassivHaus projects we use triple glazing within our energy efficient and air tight framing. We can also calculate project specific U-value calculations on the exact design that takes into account all the perimeter conditions as well as the framing arrangement for the rooflight. Please consult our specialists for more information and possible options
VITRAL's A74 and VRS systems are fully framed, with each panel sitting alongside another. There is no carrier frame as with curtain walling or patent glazing. These two systems therefore require additional framing where there is an opening vent that will stand higher than the rest of the rooflight.
With Vitral's rooglight systems we open an entire panel for ventilation so no additional framing is required. This is important for a number of reasons:
- Less frame means a lower U-value
- No additional framing to install
- Same price for fixed or ventilated panels
- Same slightline whether there are fixed or opening panels
- No visible external difference between fixed or opening panels
The VITRAL Skyvision is a range of flat rooflights that can be purchased by anyone and fitted by anyone. Because of this you don't need to use our TASC network, you can buy them directly from us via telephone .
As our roofglazing systems are bespoke, except for the VITRAL Skyview and the Panoramic, we have standard specifications that will need to be tailored to your project.
You can either download one of our standard specifications here, or contact us and we will quickly create an NBS for your project.
Vitral's bespoke range, the A74, VRS and GTS are all panel based. Each panel is independant to the unit next to it and each one is only fixed at the head of the panel and the cill.
We therefore open an entire panel for opening vents, this means there is no additional frame, no increase in U-value and the sightlines are minimised at only 48mm. The panel alongside an opening vent remains fixed so we can open alternate panels.
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VITRAL roof glazing company has an established network of installers, Trained Approved Specialist Contractors (TASC).
Using our TASC network has the following important benefits:
- Quality of Installation Can Be Assured - Vitral rooflights don't leak due to high quality manufacture and high quality installation.
- The Roof Glazing Detail is Correct - The architect often details the junction between the roof glazing and the roof, but our TASC network undertake detailing of every project they are awarded to ensure everyone involved in the contract is aware of their responsibilities and everyone knows it will work.
- No Onsite Fabrication - with all the panels manufactured to the appointed TASC installers drawings, they can save contractors time onsite with a much quicker installation as their is no onsite fabrication.
- Financial Stability - We know the financial standing of our installers and we can be confident that even in these difficullt times a project will not be delayed due to a TASC installer ceasing trading.
These are just a few reasons why the TASC network is an important resource for VITRAL, Architects and Contractors alike. Full details of our TASC network can be found here
VITRAL has three different rooflight systems that exist due to our ongoing product development, yet each one has specific features that makes them more suitable for different applications.
The GTS system is the oldest of the range and is typically used for large unheated atriums but especially where the rooflight needs to curve on the ridge or faceted in a vertical installation. Its construction lends itself to unusual designs that our other systems cannot achieve.
Examples of GTS installations:
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If this type of design is not required then the decision is between our A74 and VRS roof glazing systems. These systems have similair performance but the main difference is in their construction. The A74 is alumiunium and is often power coated, whilst the VRS is stainless steel and has a polished finish. The choice then becomes one of aesthetics and we will recommend which system would be the most applicable for you.
Smoke evacuation is typically enabled through proprietry smoke vents, that as the name suggests exist only for this purpose.
With a VITRAL Roof Glazing System, we are approved to EN12101-2, formerly BS7346 for Smoke Evacuation. The VITRAL roof glazing will be present to enable natural light into the building and typically there will be natural ventilation, so why not use the same system for Smoke Evacuation.
It requires no additional cost apart from a few motors and will save thousands on a project as there is no need to purchase and install proprietry smoke vents.
VITRAL's bespoke systems the A74, VRS and GTS typically work to two maximum dimensions, the panel length and the panel width. The longer the panel, the narrower it becomes.
The maximum panel length that VITRAL manufactures is 3000mm, at which size the width is approximately 600mm. Alternatively, the widest panel VITRAL manufactures is 1200m wide at which size the length is approximatley 2000mm.
For every project to ensure VITRAL's rooflight systems comply with all the necessary British Standards, we undertake panel size calculations which will take into account the wind loads on the panels. This will give a maximum panel size from which we will calculate the optimum layout to minimise cost and U-value.
VITRAL undertake these calculations for every project so you can be assured that our U-values will be accurate and our system will comply with every required standard.
VITRAL is chosen over any other roof glazing system for one distinct reason - performance.
We have the lowest possible U-value for a roof glazing system and we test our roofglazing on a slope. This is an important point as air behaves differently if passing by glazing, such as a vertical window, compared to when it is trapped by glass, as with roof glazing.
U-values for roof glazing can only be accurate if tested on the slope, therefore VITRAL undertake Hot Box testing so that we know our U-value figures are accurate, not based on assumed norms for materials.
You can download our performance certificates here. Feel free to contact us so that we can calculate accurate U-values for any project you may be working on.
