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Frequently Asked Questions


Welcome to the VIT Group’s Frequently Asked Questions !

Here you will find all kinds of questions and answers that will help you to learn more about glazing, but also tips on application according to the type of glazing and information about the VIT company, your orders, your deliveries…
If you do not find the answer here, please contact us directly by clicking here.
A VIT advisor will answer you as soon as possible !

What is laminated glazing used for?
This type of glazing provides extra strength and safety in the event of breakage. Its main purpose is to hold the glass in place when it breaks to prevent the spread of glass fragments and to avoid any risk of injury. It also delays break-ins, and under certain conditions can be used as a guardrail. This is made possible by the glass sheets being held together by films.

How to calculate the weight of glazing?
To calculate the weight of a pane, there is a formula to be applied: 2.5 kg / mm thickness / m².
For laminated glass, the weight of the films must be added, which is 0.42 kg/film/m².
For example, an 8 mm glass will weigh 20 kg/m² (8 x 2.5), while a 44² laminated glass will weigh 20.84 kg/m² (((4+4) x 2.5) + (2 x 0.42)).

How to calculate the thickness of an insulating glass unit?
To obtain the thickness of an insulating glass unit, you need to add the thickness of the glass products to the thickness of the air space (or air spaces in the case of a triple).
For example, 4/16/4 glazing will measure 24 mm.

How do I measure a pane of glass?
To measure a window properly, you need to be able to remove the sealant or the glazing beads from your window to get the exact measurements. All you have to do is measure the height and width of your glass.

Does thermal glazing have to be automatically fitted as double glazing?
Yes, the thermal pane is automatically fitted as double or triple glazing to ensure that it performs its function of providing good thermal insulation and therefore an optimum Ug-value, good luminosity and controlled solar gain.

Is insulating glass made up of several panes of glass for its effectiveness against noise?
VIT acoustic insulating glass is made up of at least two panes of glass of different thicknesses to improve acoustic performance : each thickness of glass reduces a different wavelength of noise. Of course, it is also possible to use a standard laminated glass or an acoustic treated glass (PVB acoustic) to further improve the performance against noise.

Visit our acoustic configurator to find your solution !

What is the role of solar control glazing?
Solar control glazing helps to control the level of heat entering in the summer and the amount of light in the summer, while preventing heat loss in the winter. This glazing is chosen according to the exposure of the building and your project. This glazing allows you to reduce the consumption of air conditioning in your building and improve your living comfort.

Moreover, the RE2020 which came into force on 1 January 2022 emphasises this point ! “The aim of this regulation is to prioritise energy sobriety and decarbonisation of energy, to reduce the carbon impact of building construction while guaranteeing comfort in the event of high heat”

Find our range by clicking here

How is the vacuum created in double glazing?
There is no vacuum between the panes ! There is only a filling of dehydrated air or Argon between the panes. The sealing is then carried out with a butyl and then a PU or silicone, in order to guarantee the glazing for 10 years against the return of humidity in normal conditions of installation and exposure.

Is triple glazing useful?
Triple glazing will provide better thermal insulation : the Ug-value can reach 0.4 W/m²°K, whereas with double glazing it can only reach 1 or even 0.9. It should be noted, however, that the energy input will be reduced in mid-season and that the use of triple glazing must therefore be carefully considered in terms of its overall performance (useful for the coldest NORTH exposure but questionable for other exposures).

Who has the right to manufacture flame-retardant or fireproof windows?
Contrary to popular belief, there is no need for specific approval or authorization to make flameproof or fireproof joinery. On the other hand, this type of work must be carried out by scrupulously respecting the reports, which we will be able to provide you, in order to respect the sections of wood, the types of profiles, the gaps, to use the good joints, etc…

This is valid for wooden frames as well as for steel or aluminum frames.

You can find all our PV here with our STOP FIRE products fireproof (Pyrobel) or flameproof (pyrobelite).

What is thermal breakage and how to spot it?
Thermal breakage occurs when the temperature difference between two areas of the same glass is too great. This generates a different expansion between the 2 zones, which leads to a breakage of the glazing.

Thermal breakage can be caused by shadows (trees, canopy, building, …) or by objects placed too close to the glazing (solid spandrel, radiator, sofa, poster, …).

The realization of JPI allows to limit the risk of thermal breakage, but the only way to avoid it 100% is to use tempered glass, which is insensitive to it.

Contact us or by phone at 03 85 81 48 08, in order to determine together the right glazing thanks to our recognized simulation software.

What is a dB ra and ratr?
The sound reduction, expressed in dB (decibels), represents the sound insulation capacity of the glazing. The higher this value is, the better the glazing is.

This attenuation has 3 categories:

dB RW: ambient noise, which takes into account most common frequencies

dB RA: pink noise, generated in the laboratory, which focuses on the medium and high frequencies

dB RaTr: also called road noise attenuation, or traffic (tr), this attenuation is specific to noise frequencies generated by road traffic (medium and low frequencies). It is therefore used for buildings located along roads, highways, cities, …

Find the acoustic performance of glazing on our configurator.

What is a RAL color chart?
A RAL color chart is an assortment of standardized colors.

We can provide you with a PDF version, but the representation of the colors is approximate, because it depends on the settings of your screen, your printer … The best is to buy a real RAL color chart in the store, or to provide you with one from a paint supplier for example.

This RAL color chart will allow you to determine the colors for your VIT Paint or enamelled glass, for the small wood pieces integrated in the insulating glass units, etc…

Please note that for our products with decorative inserts, the colors of our inserts do not correspond to a specific RAL tint. We invite you to contact a VIT consultant for more information or to ask for the specific color chart (Eurofilter or other).

The same goes for our VIT Print glazing in digital printing: we do not use RAL tints, but CMYK (Cyan-Magenta-Yellow-Black) used in the printing industry.

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What is a 1b1, 2b2 glass?
A 1b1 glass represents a laminated glass with a PVB interlayer film of a nominal thickness of 0.38mm. While a 2b2 glass, corresponds to a glass with several PVB films of 0.38mm.

Tempered glass is classified as 1C2.

You can find here the details of these safety classes.

Do the floor tiles have a direction of installation ?
Yes, floor tiles are usually made of 3 glasses : two identical glasses and one thinner glass. The thinner glass should always be placed on top, as it is a wear glass, a kind of protective layer, which will prevent the mechanical strength of the tile from being affected by wear, scratches, etc.

This wear glass is always made of tempered glass.

What are your fields of application ?
VIT has different fields of application associated with our product ranges in order to best respond to each sector: You can find them on our site :
Fittings, partitions, slabs, showers, facades, windows, railings, doors, verandas, glass roofs, shop windows.

Do you have products dedicated to joiners ?
VIT offers a wide range of glazing adapted to joiners : flame-resistant glazing VIT Stop Fire, burglar-resistant glazing VIT Stop Choc, thermal glazing VIT Therm, blackout glazing VIT Stop View, acoustic glazing VIT Acoustic, etc.
You can find our selection by clicking here

Do you have products dedicated to fitters?
VIT offers a wide range of glazing adapted to the professional fitters : shower glazing VIT Shower, glazing with decorative inserts VIT Insert, glazing with digital printing VIT Print, acoustic glazing VIT Acoustic, fireproof glazing VIT Stop Fire, railing glazing VIT Stop Fall, lacquered glazing VIT Paint
You can find our selection by clicking here.

Do you have products dedicated to facade engineers ?
VIT offers a wide range of glazing adapted to building and façade professionals: double or triple insulating glass with solar control function (neutral or reflective) VIT Perform, acoustic function VIT Acoustic, thermal function VIT Therm, burglar-proof function VIT Stop Choc Plus, flame-proof function VIT Stop Fire.
You can find our selection by clicking here.

Do you have products dedicated to partitioners ?
VIT offers a wide range of glazing adapted to professional partitioners : glazing with sandblasting VIT Sand, glazing with decorative inserts VIT Insert, burglar-proof glazing, acoustic glazing, flame-proof glazing VIT Stop Fire, anti-reflective glazing VIT Stop Reflect, blackout glazing VIT Stop View, glazing with integrated blinds VIT Line
You can find our selection by clicking here.

Do you have products dedicated to veranda builders ?
VIT offers a wide range of glazing adapted to building professionals and more specifically to veranda builders : burglar-proof glazing VIT Stop Choc, self-cleaning glazing VIT Self Clean, thermal glazing VIT Therm, insulating glazing, solar control glazing VIT Perform, heating glazing VIT Heat, acoustic glazing VIT Acoustic, etc.

Do you have any products dedicated to architects ?
VIT offers a wide range of glazing adapted to building professionals and architects : glazing for shower enclosures VIT Shower Glass, glazing with decorative inserts VIT Insert, glazing with sandblasting VIT Sand, glazing with digital printing VIT Print, heated glazing VIT Heat, acoustic glazing VIT Acoustic, thermal glazing, solar control glazing VIT Perform, glazing with integrated blinds VIT Line, thermal glazing VIT Therm, floor glazing VIT Stop Gliss, fireproof glazing VIT Stop Fire
You can find our selection by clicking here.

Do you have products dedicated to the manufacturers ?
VIT offers a wide range of glazing adapted to the manufacturers : glazing with sandblasting VIT Sand, glazing with decorative inserts, fireproof glazing VIT Stop Fire, acoustic glazing VIT Acoustic, glazing with digital printing VIT Print, etc.
You can find our selection by clicking here.

Do you have products dedicated to metal-workers ?
VIT offers a wide range of glazing adapted to metal-workers : burglar-proof glazing VIT Stop Gliss, flame-proof glazing VIT Stop Fire, thermal glazing VIT Therm, acoustic glazing VIT Acoustic, anti-reflection glazing VIT Stop Reflect, VIT Stop Fall, etc.
You can find our selection by clicking here.

A- Do you have products for silverers ?
VIT offers a wide range of glazing adapted to building professionals and silverers : glazing for shower walls VIT Shower Glass, glazing with digital printing VIT Print, glazing with decorative inserts VIT Insert, glazing with relief, acoustic glazing VIT Acoustic, thermal glazing VIT Therm, solar control glazing VIT Perform, floor glazing, anti-reflection glazing VIT Stop Reflect, glazing for railings VIT Stop Fall
You can find our selection by clicking here.

What type of glazing to choose for a facade?
VIT offers a wide range of glazing adapted to the needs of building professionals so that your glazing matches your façade as closely as possible!

The glazings recommended for the facade are chosen according to their thermal, phonic and safety characteristics. Indeed, the glazings of facade have several roles in a building: at the same time aesthetic and technical. It is therefore important to consider Technical Glazing products that comply with current standards and regulations.

However, it should be noted that we very often find solar control products from the VIT Sun range associated with safety glass from the VIT Protect range (Stop Choc and Stop Chocplus).

Come and discover our selection for all types of facades.

We are at your disposal to assist you in your project.

Which glazing to choose: single, double, triple?
Single glazing is used almost exclusively in interiors, for example to create laminated glass partitions, or for fittings (mirrors, credenzas, lacquered glass, shelves, etc.).

The double glazing is generally used outside, to have a good thermal insulation. It can also combine this insulation function with solar control, soundproofing and security functions.

As for triple glazing, it is mainly recommended to obtain a very efficient thermal insulation (Ug < 0.9 W/m²°K). It is therefore often found on the northern facade or at high altitudes in cold regions (Savoy, Jura …)

What type of glazing will protect against UV rays?
When UV protection is required, laminated glass, whether 1B1 or 2B2, filters out 99.9% of the UV rays responsible for the aging of objects, discoloration, degradation of plastics, etc. You can find our VIT Protect range here.

Attention: UV does not bring heat. You should not confuse anti-UV protection with protection against the heat brought by the sun! To control solar energy, you must choose a solar control glazing : come and discover our range in details.

How to choose your thermal glass ?
To obtain good thermal insulation performance, it is essential to use double glazing, with a low-emissivity VIT Therm and/or solar control side VIT Perform, and an argon layer, ideally 16 mm. The choice of coating can give you an Ug of 1.0 W/m²°K with double glazing and up to 0.5 W/m²°K with triple glazing. This type of glazing provides optimum thermal insulation.

What type of glazing should be used to provide the best possible insulation in a building ?
There are several types of glazing for the best possible insulation of a building. Depending on your wishes, it is possible to use fire-resistant glazing VIT Stop Fire, laminated glazing or thermal thermique VIT Therm or solar control glazing VIT Perform! It is also possible to combine several features according to your project.
To be assisted with your project, contact a VIT consultant !

Which glazing will reduce energy bills (air conditioning in summer / heating in winter) ?
The ideal glazing for reducing energy bills is solar control glazing VIT Perform. It will provide enhanced thermal insulation in cold weather, by controlling light, while limiting solar gain in summer. Thus, the heat will stay inside more easily in winter and outside in summer.

Which glazing should be prioritised to ensure the security of a building, a shop window or a home ?
The most secure glazing at VIT is part of the VIT PROTECT range. It is the STOP CHOC PLUS glazing, its primary function is to prevent or delay as much as possible the entry of a potential burglar in a public place, an office or a home. Its specific composition, combining different layers of glass and PVB, ensures security. Be sure to confirm the class of protection required with the insurer of the property to be protected, as each location, each city, each risk exposure… does not necessarily require the same protection ! A little advice for installation : when mounted as insulation with a float side, do not hesitate to place the laminated side inside the building (in fact, breaking the outer side will make it more difficult to break the laminated glass, and the resistance of PVB films is optimal at room temperature!)

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Which glazing should be prioritised for a meeting room ? Or a large room ?
The VIT DESIGN range includes sandblasted glass. It is ideal for meeting rooms because with its sandblasted glass, you obtain an opaque appearance while preserving the luminosity. It is a glazing that can be used both as a single pane and as an insulating pane and brings discretion to the room.

Click here to see our range

Is there bulletproof glazing ?
Of course there is! The STOP BULLET range meets these expectations! Its composition, based on different types of glass, PVB and polycarbonates, ensures the safety of people against firearms. In addition to the range of resistance to the type of weapon used, this range of glazing can be declined in 2 versions S (with vulcanising splinter) or NS (without vulcanising splinter) which makes it possible to meet all your expectations!

Find our range by clicking here

How to discover our VIT products ?
You can discover VIT products on our website by application, by theme or by trade, in our menu – Our products. You can thus discover all our product ranges according to your needs: thermal glazing, acoustic glazing, decorative or security glazing…

How do I place an order for VIT glazing products ?
To place an order, you can request a quote,  contact a VIT expert  or log on to your customer area. You can do all this on our website in the “Our services” category.

How to get a quote for VIT products ?
PTo obtain a quote, click on request a quote, and complete your glazing project by filling in the form! A VIT advisor will reply as soon as possible. You can also contact us directly on 03 85 81 48 08

Does VIT sell spare parts ?
VIT can offer you installation accessories (hinges, locks, knobs, etc.) for your fully glazed doors (Clarit and Securit types) and shower doors and partitions. We can also offer you the appropriate seals for your glazing (insulation, floor tiles, etc.) and silicones compatible with our glazing.

How can I track my orders/deliveries of VIT products ?
To track your orders and deliveries, go to the VIT LINK – Pro area section of our website. Via this tab, and with your personal codes, you will find the follow-up of your orders in your dedicated customer area.

Does VIT provide installation assistance, delivery to the site with a crane truck ?
VIT can offer you different delivery services :

  • Traditional delivery to the building site with unloading by you,
  • Delivery to the building site with a crane truck or truck-mounted unloader,
  • Delivery with installation assistance thanks to our partners equipped with cranes, mini-cranes, vacuum lifting devices, etc. Your glazing will then be delivered, handled and placed in your joinery with the greatest care to ensure smooth installation !

Simply contact VIT to set up your project and specify that you would like this assistance.

How to declare a dispute, or a defective / non-conforming product ?
If you receive a defective product following an order at VIT, it is possible to make a return by filling in the following document. You will then be able to give the defective glass back to the deliveryman, during his next visit. Once the glazing is returned, the defect will be analyzed, and the replacement of the glazing will be taken in charge or not, depending on the origin of the defect.

How to declare a delivery breakage (declaration modalities and deadline, etc.)?
A breakage of glass during a delivery can happen. In case of breakage during the delivery of a window, you can declare it directly on the delivery note in the presence of our driver. It will then be taken care of and the glass will be refabricated free of charge and delivered on your next delivery.

If you notice the breakage after the deliveryman has left, you can recommend the glazing to us as usual, by sending us a copy of the delivery note for example, so that we can put the glazing back into production. In this case, it will be invoiced.