England · 46 postcode districts
Hertfordshire insulated fire glass
Our Hertfordshire insulated fire glass service covers survey, supply and installation to the tested details, documented on handover.
EI 30 – EI 120EnglandSGWDAL
Quote for Hertfordshire
Tell us what you need. We reply with next steps and a guide price.
Insulated Fire Glass (EI) by town in Hertfordshire
Our Hertfordshire coverage spans 46 postcode districts across the SG, WD, AL, HP postcode areas.
Watford (WD17)Hemel Hempstead (HP3)Stevenage (SG1)St Albans (AL1)Welwyn Garden City (AL8)Cheshunt (EN8)Hatfield (AL10)Bishop's Stortford (CM23)Borehamwood (WD6)Hitchin (SG4)Hoddesdon (EN11)Letchworth Garden City (SG6)Harpenden (AL5)Bushey (WD23)Hertford (SG13)Rickmansworth (WD3)Potters Bar (EN6)Berkhamsted (HP4)
Insulated Fire Glass (EI): what you get in Hertfordshire
EI glass is the choice where people need to pass close to the glass during a fire, where combustible materials sit near it, or where building guidance would otherwise restrict glazing. We supply and fit EI 30 to EI 120 glass in tested frames, internally and externally.
- Internal and external-grade build-ups
- Insulating glass in sealed double-glazed units
- EI 30, EI 60, EI 90 and EI 120 glass
What to check before ordering in Hertfordshire
How it works
When heated, the interlayers turn opaque and expand, forming an insulating shield. After a fire the glass will need replacing.
The temperature rule
EI testing limits the average temperature rise on the unexposed face to 140°C and any single point to 180°C, which is why people can pass it.
Optical quality
Modern EI glass is clear in normal use, with high light transmission at lower ratings.
Regulations for Hertfordshire projects
England Which rules apply?
Building work in England is covered by the Building Regulations 2010, with fire safety guidance in Approved Document B and impact safety guidance for glazing in Approved Document K.
Once a building is in use, the Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to maintain fire safety measures, including fire-resisting glazing. The Fire Safety (England) Regulations 2022 add duties for multi-occupied residential buildings, including fire door checks in buildings over 11 metres.
In higher-risk buildings, broadly 18 metres or seven storeys with two or more homes, the Building Safety Regulator is the building control authority. England is also phasing out BS 476 references from Approved Document B, with the remaining fire-resistance references due to go in September 2029.
FAQs for Hertfordshire
What does EI 60 mean?
The glazing system kept fire on one side (integrity) and limited the temperature rise on the other side (insulation) for at least 60 minutes in a standard fire test.
Is EI glass clear?
Yes, in normal conditions. It turns opaque only when heated in a fire.
Why is insulated fire glass so much more expensive?
It is a multi-layer product with specialist interlayers, and the frame and installation must suit its weight.
Can you survey anywhere in Hertfordshire?
Yes. We can arrange surveys anywhere in Hertfordshire, including Watford and Hemel Hempstead, Stevenage, St Albans, Welwyn Garden City.
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Process
How a Hertfordshire job runs
Start with the brief
Tell us the rating required, sizes and building type, or ask us to find out.
Survey
We visit Hertfordshire to measure, record existing marks and check the frames and substrate.
Written proposal
We set out the system, glass, evidence and programme, with a fixed price.
Fit and record
We install, photograph seals and fixings before closing up, and hand over the schedule.