Technical Information

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Glazing Details
 ·  Non fire-rated doors
 ·  Fire-rated Doors and Fire Resistant glazing systems
 ·  Lorient FF1 System
FD60 Fire Rated Glazing Products
Fire and acoustic ratings for doors
Acoustic Ratings and Seals
Door Cores

Glazing Details

Glazing details for Non fire-rated doors

No size limitations imposed on glass size, although for structural stability we would not recommend leaving a margin of less than 100mm all round and preferably a bottom rail of 200-300mm.

Types of glass (non-exhaustive)

• 6.4mm or 10.8mm clear laminated glass
• 6.0mm or 10.0mm clear toughened glass
• 6.0mm Georgian wired polished glass (up to 250mm wide)
• 6.0mm Georgian wired cast glass (up to 250mm wide)
• 6.0mm Georgian wired polished safety (over 250mm wide)
• 6.4mm Whispaply (clear glass for acoustic doors)

Types of glazing beads

The most popular (and most cost-effective) section is the standard ‘hockey-stick’ section, which is illustrated along with a few other examples of glazing bead sections. The glass will typically be glazed with Lorient FF1 glazing system for NFR doors.

Flush glazing beads are a more attractive, but more costly option and other types of glazing systems may be applicable.

Glazing details for fire-rated doors and Fire Resistant glazing systems

Design Needs

The Building Regulations require large buildings to be sub-divided into smaller volumes or areas bounded by building elements which resist the spread of fire and smoke. Building a fire resistant wall is a relatively simple task. More complex is how to deal with glazed apertures. Gaps, joints and interfaces between dissimilar materials invariably form points of weakness. Provision needs to be made to seal these effectively and glazed apertures form an important part of this construction.

The Solution

The solution is to fit a fire resistant glass secured using proprietary fire resistant glazing systems. These hold the glass firmly in place during normal use, but in the event of a fire the intumescent material expands, securing the glass and insulating and protecting the surrounding timber.

There are no specific test procedures to determine the performance of a glazed aperture in relation to smoke.

Lorient systems are designed to minimize smoke transfer yet fit tightly on the perimeter of the glass and eliminate undesirable rattle at the same time.

Regulatory Requirements

The requirements for fire and smoke containment with respect to ‘means of escape’ are contained in Approved Document B to the Building Regulations (England and Wales), Part E of the Scottish Technical Standards and Part E to the Building Regulations (Northern Ireland).

Document N to the Building Regulations and Technical Booklet V to the Building Regulations (Northern Ireland) give guidance and requirements affecting safety in use, particularly impact resistance. A distinction is drawn between glass which is fixed and that which moves (as in doors). Document N needs to be considered in conjunction with Document B.

Relevant Standards

There are several British Standards which relate to glazing; they include:

BS 476: Pt. 22: 1987: Methods for determination of the fire resistance of non-loadbearing elements of construction

BS 5588: Fire precautions in the design and construction of buildings. (An Approved Document for compliance with Building Regulations).

Fire Protecting Glazed Apertures

In door assemblies, especially those on circulation routes, glazed apertures allow people to see others approaching from the opposite direction: they also allow fire and smoke to be seen without opening the door thereby making a real contribution to safety.

When forming a glazed aperture in a fire resisting door it is essential that fire resistant glass is used. The most commonly specified is Georgian wired glass but other non-wired glass types have been tested too, and are more popular in projects with fewer budget constraints.

Proprietary intumescent glazing systems, such as the Lorient FF1 are designed to prevent or delay possible modes of failure in either the glass or its surroundings.

Lorient FF1 - Description

Lorient FF1, when incorporated with an appropriate bead detail, is an effective intumescent seal, providing a solution for 30 minute fire resistant glazed doors. [For uniformity we also use this system with NFR doors]

This system has the following advantages:

• Unique design which enables tolerances between door, bead and glass thicknesses to be accommodated, minimises glass rattle and is good for acoustic containment
• Special cap gives neat aesthetics and provides the locating point for fixing to the glazing bead for ease of application
• Seal has a self-adhesive backing for ease of fitting
• Hardwood or softwood beads can be used (min density 550kg/m³) depending on door core
• Seal and bead can be mitred at the same time, saving labour costs
• Available in black as standard but white and light brown can be offered to special order
• Available in 50 metre coils.

Illustration of Lorient FF1 Glazing System

NB: Bead dimension could vary depending on glass type and door thickness.

Operation

In every day use, Lorient FF1 offers firm support with a degree of flexibility which absorbs shocks and minimises glass rattle. When exposed to fire, the intumescent material expands forming a stable insulating seal which prevents the retaining beads from ignition on the non-fire side of the door.

Fixing

Beads are retained using 40mm long steel pins at 150mm nom. centres or steel screws 40mm long (No. 8) at 150mm nom. centres.

Performance

Provides 30 minutes fire resistance when used with:

Door Cores:

• Solid laminated timber e.g. Softwood lamel
• Solid chipboard [Halspan]
• Flaxcore – in conjunction with either 20mm hardwood liner (min density 640 kg/m³),
  Intumescent liner LX4402 or saddle bead (min density 640 kg/m³)

Glass Types:

• GWPP
• Pyroshield^® 6mm
• Pyran S^® 6mm
• Firelite^® 5mm
• Pyrodur Plus^® 7mm
• Pyroguard^® 7.2mm
• Pyrostem^® 7mm
• Pyrobelite^® 7mm

Aperture size:

• 875mm high x 750mm wide or as approved and tested by core manufacturer.
• e.g. Halspan can certify multiple apertures up to 1.28m²

FD60 Fire Rated Glazing Products

Thermaglaze 60 – 60 minute glazing system for use in fire doors only

Thermaglaze 60 is a phosphate based intumescent encased in a PVC sleeve. The system carries enviable test evidence for use on previously tested doorsets and can be wholeheartedly recommended. Tested to BS 476 part 20:22 achieving well in excess of the 10% safety barrier, it comes in a range of colours offering a slim 4mm sight line each side of the glass.		Size: 25mm x 4mm / 54mm x 2mm Liner Fire Rating: 60min* British Standard: BS476 Pt 20:22 Description: Superb 60 minute option. Fast to install with self colour sight lines, self-adhesive application. We like this one! Colours: White, Brown, Black, Cream Length: 2.1m * for guidance only, please refer to our technical department for test evidence.

Fire and acoustic ratings for doors

It should be noted that 20 minute ratings which are sometimes specified no longer apply.

30 minute fire-rated doors

Core and thickness — Halspan Engineered Particle Board — minimum 44mm

Size limitations for single doors and pairs of doors, also overpanels — see charts www.halspan.com

Intumescent/smoke seals

Intumescent seals for FD30 doors are as noted below and in the accompanying sections. It should be noted that intumescent/smoke seals should be fitted if required by the Local Authority. These are similar to the ordinary intumescent seals but with the addition of brush or rubber fin seals. For pairs of doors, only one seal/set of seals is required where the doors meet.

Frames and stops

Minimum thickness of frame is 32mm and softwood may be used. There is a minimum of thickness for the stops — 12mm.

60 minute fire rated doors

Core and thickness — Halspan Engineered Particle Board — minimum 54mm

Size limitations for single doors and pairs of doors, also overpanels — see charts www.halspan.com

Intumescent/smoke seals

Intumescent seals for FD60 doors are as noted below and in the accompanying sections. It should be noted that intumescent/smoke seats should be fitted if required by the Local Authority. These are similar to the ordinary intumescent seals but with the addition of brush or rubber fin seals. For pairs of doors, only one seal/set of seals is required where the doors meet.

Frames and stops

Minimum thickness of frame is 32mm and hardwood min. density 650 kg/m³ must be used. The minimum thickness for the stops is 12mm, and these should also be hardwood.

Acoustic Ratings and Seals

There are a multiplicity of Acoustic seals available, with various ratings and aesthetic qualities. Experience has shown that clients invariably expect to achieve the best sound reduction with the best aesthetic qualities, taking into account cost and durability, and we have therefore drawn up the illustrations accordingly.

Section through door and frame showing seals	Stop Seal - IS7025	Automatic Drop-Down Threshold Seal  - IS8010 Si

In addition, the following chart shows the maximum decibel reductions achievable.

We can produce standard doors with up to 38dB RW/STC but have recently supplied doors for a national distribution centre which were tested at 47dB RW/STC.

Door Cores

We generally use Halspan Cores for our internal door manufacturing. For any technical information, related to firerated door sizes, glazed apertures, etc. please refer to www.halspan.com

We also utilise other cores such as Sentry, Flamebreak and Blankfort for more specialised applications.