Fire-resistant glass is special glass that helps to temporarily stop fire, smoke and heat. You mainly see it in buildings where fire safety is important, such as offices, apartment complexes, schools, healthcare buildings, stairwells and business premises. But it can also sometimes be necessary in homes, for example at a door to a garage or a window close to the property line. The short rule is: fire-resistant glass is used when a wall, door, window or facade is part of a fire-resistant partition. The glass must then provide the same fire-resistant performance as the structure in which it is placed.
In this article we explain what fire-resistant glass is, which classes there are (E, EW and EI), what 30, 60 and 90 minutes mean, and what you should pay attention to when choosing, installing and regulations.
What is fire resistant glass?
Fire-resistant glass offers resistance to fire, smoke and sometimes heat for a certain period of time in the event of a fire. It is used in structures that need to retard fire, such as:
- fire-resistant doors and facades;
- windows in escape routes;
- glass next to stairwells;
- glass between fire compartments;
- glass in partition walls and technical areas;
- glass between house and garage;
- glass in office walls, schools and healthcare buildings.
The goal is not for the glass to stop the fire forever. The aim is for the fire to spread less quickly for a certain period of time, so that people can escape safely and the fire brigade has more time.
Why is fire-resistant glass important?
In the event of a fire, time counts. If fire, smoke and heat spread quickly, escape becomes more difficult and damage grows faster. Fire-resistant glass helps to temporarily contain fire within a compartment. It contributes to:
- slowing down the spread of fire;
- protecting escape routes and adjacent spaces;
- limiting smoke spread;
- meeting fire safety requirements;
- preservation of view and daylight via transparent fire-resistant partitions.
Without fire-resistant glass, a fire-resistant wall or door could lose its function as soon as it contains glass.
When do you need fire-resistant glass?
Fire-resistant glass is necessary when the glass is part of a fire-resistant construction: a wall, door, window, facade or facade. Common situations are:
- door or window in a fire-resistant wall;
- glass in an escape route;
- glass between fire compartments;
- window near a stairwell or next to a fire-resistant door;
- glass between house and garage;
- glass in a technical room or meter cupboard;
- glass in an apartment complex, office or business premises;
- glass close to a plot boundary;
- glass in a school, healthcare institution or public space.
Whether fire-resistant glass is mandatory depends on the function of the building, the location of the glass and the fire resistance requirement for the entire construction. If in doubt: have it assessed based on the construction drawing, permit or fire safety requirements of the project.
Fire-resistant glass in homes
In ordinary homes, fire-resistant glass is less often required than in commercial buildings or apartment complexes. Yet it does occur, for example in:
- glass in a door between the house and the garage;
- glass next to an indoor garage;
- a window close to the property boundary;
- glass in a technical room;
- a home above or next to a business premises;
- apartments with communal escape routes;
- a renovation that requires fire-resistant separations.
Fire-resistant glass in apartments
Fire-resistant glass is more common in apartment complexes because there are common escape routes, stairwells and corridors. It may be necessary for home entrance doors, side lights next to front doors, glass in corridors and stairwells, glass between storage rooms and escape routes, fire-resistant facades and smoke separations. The goal is that residents can escape safely and that fire and smoke spread less quickly through the building.
Fire-resistant glass in offices and commercial buildings
In offices and commercial buildings, fire-resistant glass combines openness and daylight with fire safety. Applications include glass office walls, fire-resistant doors, corridors and escape routes, meeting rooms, stairwells, separations between fire compartments, technical rooms, warehouses, production areas and entrances. It is especially useful when you want to create transparent walls without reducing the fire safety of the building.
Fire resistant glass per application
In doors
Fire-resistant doors sometimes have a glass opening. Het glas moet dan passen bij de brandwerendheid van de deur. NB:
- the door must be fire-resistant;
- the glass must be fire-resistant;
- the frame and glazing beads must be suitable;
- the sealant or tape must be fire-resistant;
- installation must be carried out according to instructions.
So you cannot simply install standard glass in a fire-resistant door. The entire door construction must be correct as a whole. Would you like to know more about glass in custom doors? Then read custom glass door.
In windows
Windows can also be part of a fire-resistant separation, for example between two fire compartments or on a facade close to a property boundary. Fire-resistant glass in windows is used for indoor windows, windows in fire-resistant walls, windows in stairwells and in technical rooms, facade windows with a fire spread risk, windows between home and garage and windows in commercial buildings. The glass must match the fire resistance requirements of the frame and wall.
In escape routes
Escape routes must remain usable during a fire. That is why fire-resistant glass is often important there, such as corridors, stairwells, porches, emergency exits, entrances, common areas and routes in schools, offices and healthcare buildings. If there is glass in or next to an escape route, fire, smoke or heat must be prevented from rendering that route unusable too quickly.
Between house and garage
An indoor garage can pose an additional fire risk due to flammable materials such as fuel, paint, machines, electric bicycles or batteries. If a garage is directly adjacent to the home, a fire-resistant separation may be necessary. If there is glass in that separation, then that glass must also be fire-resistant — for example, a door with glass between the garage and the home, a window between the garage and the utility room, glass next to the garage door to the home or glass in the dividing wall. Never use just normal glass here if the wall or door must be fire-resistant.
At the property line
With facades close to the property boundary, fire spread to an adjacent plot can play a role. Fire-resistant requirements may then apply to windows or facade parts, for example windows close to the plot boundary, extensions and extensions, commercial buildings, houses close together, facades next to firebreaks and projects with a fire spread calculation. This is highly dependent on the construction situation. If in doubt, have it assessed by a structural engineer or fire safety advisor.
What types of fire-resistant glass are there?
Fire-resistant glass is available in different classes. The main difference is in what holds the glass back. The letters indicate what the glass does in the event of fire:
- E — flame tightness: retains flames and hot gases.
- EW — flame density with limitation of heat radiation: one step higher than E alone.
- EI — flame tightness and thermal insulation: the toughest of the three main categories.
What does E mean?
E stands for flame density. The glass prevents flames and hot gases from entering the structure for a certain period of time. E-glass therefore stops fire, but limits heat radiation less strongly than EW or EI. It may be suitable when flame penetration must be prevented, but is not always sufficient if people need to be able to escape close to the glass.
What does EW mean?
EW means that the glass is flame-tight and limits heat radiation. It is often used where fire resistance is needed, but full thermal insulation is not always required. Because it limits radiant heat on the safe side, it can be important for escape routes or adjacent areas.
What does EI mean?
EI is flame-tight and thermally insulating. It not only limits flames and smoke, but also the temperature rise on the safe side. EI glass is used when the other side of the structure must remain relatively safe in terms of temperature during the fire. It is often thicker, heavier and more expensive than E or EW glass.
What does 30, 60 or 90 minutes mean?
Fire-resistant glass is indicated with a duration, such as 30, 60, 90 or 120 minutes. The letter and the time together form the class:
| Indication | Meaning |
|---|---|
| E30 | 30 minutes flameproof |
| EW30 | 30 minutes flameproof + limitation of heat radiation |
| EI30 | 30 minutes flameproof + thermal insulation |
| E60 | 60 minutes flameproof |
| EW60 | 60 minutes flameproof + limitation of heat radiation |
| EI60 | 60 minutes flameproof + thermal insulation |
Which class is required depends on the fire resistance requirement of the structure.
Fire-resistant glass is part of a system
A common mistake is thinking that only the glass is enough. Fire resistance always concerns the entire construction. A fire-resistant glass construction consists of:
- fire-resistant glass;
- a suitable frame;
- fire-resistant glazing beads;
- the correct sealant or glazing tape;
- correct mounting and rebate;
- the correct dimensions;
- assembly according to instructions.
If one part is incorrect, the fire resistance may be lost.
Rule of thumb: fire resistance applies to the entire system — glass, frame, glazing beads, sealant and mounting together. You cannot simply place fire-resistant glass in any frame and expect the entire structure to be fire-resistant.
Fire-resistant glass in a wooden frame
Fire-resistant glass can be used in wooden frames, but only if the frame is suitable for the required fire resistance. Pay attention to the type of wood, profile dimensions, rebate depth, glazing beads, fire-resistant sealant, mounting method, maximum glass dimensions and the certification or test structure. A standard wooden frame is not automatically fire-resistant.
Fire-resistant glass in a steel frame
Steel frames are often used for fire-resistant facades and doors. Steel is strong and suitable for slim profiles, but here too the system must be tested and suitable: profile type, fire-resistant glazing, fire-resistant seal, mounting, glazing beads, door or facade construction and maximum dimensions. Steel fire-resistant glass facades are widely used in offices and public buildings.
Fire-resistant glass in an aluminum frame
Aluminum fire-resistant systems also exist, but ordinary aluminum is not automatically fire-resistant — it quickly loses strength at high temperatures, so the profile must be specially designed. Pay attention to a fire-resistant aluminum system, thermal break, the glass structure, fire-resistant rubbers, test certificates and maximum dimensions.
Combining fire-resistant glass with other requirements
With insulating glass
Fire-resistant glass can be combined with insulating glass when you need fire safety and heat insulation, for example with facade windows, doors between the inside and outside, heated rooms, apartments, offices, schools and healthcare buildings. Fire-resistant insulating glass is often thicker and heavier than standard HR++ glass. Therefore, always check whether the frame and fittings are suitable. Are you simply looking for insulating double glazing without fire requirements? Then you can assemble insulating glass yourself.
With safety glass
Fire-resistant glass is not automatically the same as injury-resistant glass. Sometimes it does have a safety glass structure, but you have to check that — especially at doors, sidelights, low windows, schools, public buildings, daycare centers and escape routes. If glass must also be injury-proof, the structure must meet both requirements. If it concerns a separate injury-safe application without fire requirements, please check with us safety glass or put together custom-made laminated glass. You can read more about this in safety glass under 85 cm and tempered or laminated glass.
With sound insulation
Fire-resistant glass can sometimes also have soundproof properties, especially when it consists of multiple layers. But it is not automatically the best choice against noise. If you want fire resistance and sound insulation, the glass structure must be tailored to this: fire class, noise value, glass thickness, frame, gap seal, door seal and ventilation openings. With doors, gap sealing is often just as important as the glass. See also soundproof glass: what works.
Order, place and recognize
Can you order fire-resistant glass to size?
Fire-resistant glass is usually made to measure, but not every size is possible. The maximum dimensions depend on the type of glass, the fire class and the system. When ordering, it must be clear: the desired fire class and duration, the glass dimensions, the frame system, indoor or outdoor application, whether or not insulating glass, safety requirements, any noise requirements and the installation instructions. With fire-resistant glass, "about right" is not enough — the specifications must be exactly right. Are you unsure about measuring? Read measure glass.
Can you install fire-resistant glass yourself?
In most situations, installing it yourself is not wise. Fire-resistant glass must be installed as prescribed, otherwise the performance may be lost. Risks of installing it yourself include incorrect sealant, incorrect glazing beads, insufficient rebate depth, glass that is not supported correctly, an unsuitable frame, lapsed certification, fire resistance that is not achieved and liability risk. Professional installation is highly recommended.
How do you recognize fire-resistant glass?
Fire-resistant glass is not always easy to recognize. Sometimes there is a stamp, marking or product code in the glass; With insulating glass, information can also be contained in the spacer. Look at the glass stamp, the product code, a marking in the corner, documents from the supplier, the certificate, the construction drawing, the invoice and any fire resistance report. Are you unsure whether existing glass is fire-resistant? Don't just assume — get it checked.
Can you replace normal glass with fire-resistant glass?
Sometimes yes, but only if the entire construction is suitable. Fire-resistant glass is often thicker and heavier than normal glass, and the frame must also match the required fire resistance. Check whether the glass thickness is suitable, whether the frame is fire-resistant, whether the glazing beads are suitable, whether fire-resistant sealant is required, what the required class is, whether the fittings are suitable, whether the door or wall has been tested with glass, and what the maximum dimensions are. Just replacing the glass is not always enough.
Replace fire-resistant glass
If existing fire-resistant glass needs to be replaced, you must replace it with the same or a suitable equivalent performance. Pay attention to the existing fire class, the dimensions, the glass structure, the frame system, the mounting method, the certificates, the door or wall function and the location in the building. Never replace fire-resistant glass without knowing which requirements apply in that location.
How much does fire-resistant glass cost?
Fire-resistant glass is more expensive than standard glass. The price depends on the fire class, thickness, dimensions and structure. The E, EW or EI classification, the duration (30, 60, 90 or 120 minutes), single or insulating glass, a safety structure, sound insulation, the frame system, installation, certification and dimensions are also decisive. For example, EI60 glass is usually more expensive than E30 glass because it has much heavier performance.
Common mistakes with fire-resistant glass
- Thinking that only the glass counts — fire resistance applies to the entire system: glass, frame, glazing beads, sealant and installation.
- Just place glass in a fire-resistant door — then the door loses its fire-resistant function.
- Choose incorrect classification — E, EW and EI do not mean the same thing.
- Confusing Minutes — 30 minutes is not the same as 60 minutes; the requirement must match the situation.
- Do not check frame — a standard frame is not automatically suitable.
- Assemble yourself without instructions — incorrect installation can completely undermine the fire resistance.
- Do not keep documentation — certificates, product details and invoices are important.
Selection aid: which fire-resistant glass do you need?
The table below provides a general direction. The exact class always depends on the requirement for the entire construction - if in doubt, have this assessed.
| Situation | Possible direction |
|---|---|
| Glass in fire resistant door | Glass according to door certificate |
| Glass in escape route | Fire class according to requirement |
| Glass between fire compartments | Often EW or EI, depending on requirement |
| Glass in stairwell | Fire-resistant structure according to project |
| Glass between house and garage | Fire resistant glass if separation required |
| Glass close to property line | Depending on fire spread risk |
| Office wall with fire resistance | System glass in fire-resistant facade |
| Exterior window with insulation requirement | Fire-resistant insulating glass |
| Door with injury safety | Fire resistant safety glass |
| Sound and fire resistance | Special composite structure |
Checklist before ordering fire-resistant glass
- Is fire-resistant glass really required?
- Which fire class is required: E, EW or EI?
- How many minutes of fire resistance are required?
- Is the glass part of a door, wall, window or facade?
- Is the frame suitable, including glazing beads and sealant?
- Is there a system certificate or test report?
- Is insulating glass necessary?
- Does the glass also have to be safety glass or sound-resistant?
- Are the maximum dimensions allowed?
- Is it professionally installed and the documentation kept?
- Does the weight fit the door, frame and fittings?
Conclusion
Fire-resistant glass is used when glass is part of a fire-resistant partition, such as a door, wall, window, facade or escape route. It helps to temporarily stop fire, smoke and heat, so that fire spreads less quickly and people can escape more safely. Pay close attention to the rating: E, EW and EI do not mean the same thing, and 30 minutes is different from 60 minutes. The right choice depends on the fire resistance requirements of the entire structure. And remember: fire-resistant glass only works well if the entire system is correct — glass, frame, glazing beads, sealant, fittings and installation. So don't just install fire-resistant glass in any frame, always check the requirements and preferably have fire-resistant glazing installed professionally.
Please note: we do not supply fire-resistant glass as a separate product. If you do need injury-resistant glass, look at safety glass or put together custom-made laminated glass. Are you unsure which requirement applies to your location or would you like advice about customization? Please feel free to contact with us.
Further reading: tempered or laminated glass and what is laminated glass.