- Submitted by Afiti Global

Field of direct applications of resistance to fire tests on glazed elements of construction

1. General

The field of direct application defines the allowable changes to the test specimen following a successful fire resistance test. These variations can be applied automatically without additional tests, evaluation, calculation or approval.

2. Glazed doors and window assemblies

2.1. General

2.1.1. This section outlines the permissible variations to the size and construction of doors with glazed elements and glazed window assemblies tested in accordance with IS16947 or IS 17518-1.

2.1.2. The number of leaves and the mode of operation (eg. Sliding, swinging, single action, double action) shall not be changed

2.1.3. Where the paint finish is not expected to contribute to the fire resistance of the door, alternative paints are acceptable and may be added to door leaves or shutter or frame products. This is applicable when unfinished/unpainted specimens were tested.

2.1.4. Where the paint finish contributes to the fire resistance of the door (e.g. intumescent paints), then no change shall be permitted.

2.1.5. Decorative laminates may be permitted to the faces but not on the edges of hinged doors that satisfy the insulation criteria. However, the maximum allowable thickness is 1.5mm.

2.1.6. If decorative laminates of thickness more than 1.5 mm is to be used, then the same shall be tested as a part of the test specimen. For all products tested with decorative laminate faces, the variation is limited to similar type and thickness of the material tested (eg. for colour, pattern, manufacturer)

2.2. Timber Constructions

2.2.1. Thickness of the door panel(s) shall not be decreased.

2.2.2. The door panel thickness and/or density may be increased. This increase shall not cause an increase in total weight by more than 25%.

2.2.3. For timber-based board products (eg. particle boards etc.) the composition (eg. type of resin) shall not change from that tested.

2.2.4. Crossection dimensions of timber frames may be increased but shall not be reduced.

2.3. Metal construction

2.3.1. The dimensions of metal wrap-around frames may be increased to accommodate increased supporting construction thickness.

2.3.2. The Thickness of the metal may be increased by up to 25% but shall not be decreased.

2.3.3. The type of metal/alloy shall not be changed from that tested.

2.3.4. For uninsulated doors the number of stiffening elements within the panel may be increased proportional to the size but shall not be reduced.

2.4. Glazing

2.4.1. The type of glass shall not be changed from those tested.

2.4.2. The edge fixing technique, including type and number of fixings per meter of perimeter shall not be changed.

2.4.3. The number of glazed apertures and dimensions (width and height) of glass of each pane used in a test specimen shall not be increased beyond the tested pane size but may be
a) decreased in proportion with door size reductions;
b) decreased by a maximum of 25% for integrity only and/or radiation control doorsets and for doorsets which satisfy the insulation criteria where the unexposed surface temperature for both the door leaf and the glazing have been maintained for the classification period; or
c) decreased without restriction provided that the total area of the tested pane(s) is less than 15% of the door leaf or side/over panel area.

2.4.4. The distance between the edge of glazing and the perimeter of the door leaf, or the distance between glazed apertures shall not be reduced from those incorporated in test specimens.

2.4.5. Other positioning within the door can only be modified if this does not involve the removal or re-positioning of structural members relative to the glazing.

2.5. Fixings/Hardware

2.5.1. The number of fixings used to attach fire-resisting doors to the supporting construction (eg. anchor bolts) may be increased but shall not be decreased. The distance between the fixings may be decreased but shall not be increased.

2.5.2. Hardware changes are permitted provided that it is demonstrated in a standard fire resistance test that their inclusion in other door sets of similar construction and configuration is not a cause of integrity failure.

2.5.3. Any movement restrictors such as locks, latches and hinges may be increased but shall not be decreased.

2.5. Fixings/Hardware

2.5.1. The number of fixings used to attach fire-resisting doors to the supporting construction (eg. anchor bolts) may be increased but shall not be decreased. The distance between the fixings may be decreased but shall not be increased.

2.5.2. Hardware changes are permitted provided that it is demonstrated in a standard fire resistance test that their inclusion in other door sets of similar construction and configuration is not a cause of integrity failure.

2.5.3. Any movement restrictors such as locks, latches and hinges may be increased but shall not be decreased.

2.6. Permissible Size Variations

2.6.1. Doorsets of sizes different from those of tested specimens are permitted based on the product and the length of time that the performance criteria are fulfilled.

2.6.2. The increase and decrease of dimensions permitted by the field of direct application are applicable to the overall size and to each door leaf, each side panel and each over panel independently.

2.6.3. The amount of variation of size permitted is dependent on whether the classification time was just reached (Category A) or whether an extended time was fulfilled before the test was concluded (Category B).

2.6.4. Irrespective of the allowable increase in the size of the door, the dimensions (width and height) of any glass pane cannot be increased.

2.6.5. No increase in size is permitted for uninsulated doors. This is because any increase in the size of an uninsulated door will increase the radiation received at a fixed distance away from the door.

2.6.6. Doors that satisfy both the insulation criteria and the radiation control level may increase their size provided they satisfy the overrun requirements for category B mentioned in Table 1. This is accepted because the increase in radiation resulting from the increase in the size of an insulated door will be such that it will satisfy the required radiation control levels.

2.6.7. Unlimited size reduction is permitted for all types of both categories except for insulated metal doors.

2.6.8. For insulated metal door sets of category A and category B, a reduction of 50% in width and 75% in height of the tested specimen is permitted.

2.6.9. For insulated doorsets which satisfy the overrun requirements of category B, the increase in size is permitted up to a maximum of
15% height
15% width
20% area

2.7. Gaps

The maximum size of the primary gaps in the hinged and pivoted doorsets are restricted to the following sizes in practice.
x=(a+b)/2+2mm
Where,
x is the maximum permitted gap size;
a is the maximum measured gap size;
b is the mean measured gap size.

2.7.2. The minimum size of the primary gaps may be reduced

2.7.3. Permitted gap size may be different for different parts of the door or window.

2.7.4. For horizontally sliding and vertically sliding doorsets the maximum gap at the bottom of the door may be decreased from the maximum tested but shall not be increased above the maximum tested.

2.8. Asymmetrical Doors

2.8.1. Separating elements required to be fire resisting from both sides, two test specimens shall be tested (one for each direction) unless the element is fully symmetrical, i.e. the construction of the doorset is identical on both sides of a centre line through the thickness of the door leaf when viewed in plan (from above).

2.8.2. However, in some cases it is possible to develop rules whereby the fire resistance of an asymmetrical doorset tested in one direction shall also apply when the fire exposure is from the other direction to asymmetrical doorset. The rules in 2.8.3 represent the minimum level of common agreement which shall be followed.

2.8.3. Specific Rules

The rules governing the applicability of tests carried out in one direction to other directions are given in Table 2. They are based on the following premises:

a) Each of the leaves are themselves of symmetrical construction with the exception of the edges, for example, lock/leading edge and hinge edge or double rebated doors;

b) Any restraining/supporting elements of building hardware have a melting point not less than 1000°C, or the element of building hardware previously satisfied a test as per the specified Indian Standard, when exposed in both directions and will retain their function to the exposed heat during the test.

c) There is no change in the number of leaves or the mode of operation, for example, sliding, swinging, single action or double action; and

d) Side, over and transom panels are excluded from Table 2 unless they are fully symmetrical.

2.8.4. Table 2 lists the type of doorset for which rules can be generated for the direction in which it should be tested to cover the opposite direction. The separate columns for the integrity and insulation criteria reflect the different conditions to deliver the rules for integrity-only doors as opposed to those which satisfy both criteria. ‘Yes’ means that it is possible to identify the direction of test which also satisfy the opposite direction. ‘No’ indicates that it is not feasible to identify the direction which will also satisfy the opposite direction.

Table 2 Type of doorset and direction to be tested to cover the opposite direction

2.9. Supporting Construction

2.9.1. General: The fire resistance of a door assembly tested in one form of standard supporting construction may or may not apply when it is mounted in other types of construction. Generally, the rigid and flexible types are not interchangeable and rules governing the direct application within each group are given in 2.9.2 and 2.9.3.

However, in some cases it is possible for the result of a test on a particular type of door assembly tested in one form of standard supporting construction to be applicable to that door assembly when mounted in a different type of standard supporting construction. Specific rules governing the situation for hinged and pivoted door assemblies are given in 2.9.3.

2.9.2. Rigid Standard Supporting Construction (High or Low density):
The fire resistance of a doorset tested in a high or low-density rigid standard supporting construction can be applied to a doorset mounted in the same manner in a wall provided the density and the thickness of the wall are equal to or greater than that in which the doorset was tested.

2.9.3. Specific rules for hinged or pivoted doorsets, openable windows and sliding doors

a) For timber door leaves hung in timber frames, the result of a test in a rigid supporting construction is also valid for that doorset mounted in a flexible construction and vice versa.
b) For timber door leaves hung in metal frames, the result of a test in a flexible standard supporting construction is also valid for that doorset mounted in a rigid construction and vice versa.
c) For insulated metal door leaves hung in metal frames, tests shall be undertaken in both flexible and rigid supporting constructions separately to cover both flexible and rigid supporting constructions.
d) For uninsulated metal doorsets, the result of a test in a rigid supporting construction is applicable to that doorset mounted in a flexible construction, but not vice versa.

2.9.4. The rules above are true when the fixing methods used in each type of supporting construction are appropriate to that construction. For example in a), the test on the timber door leaf in a timber frame would have been carried out with appropriate fixings for timber frames in rigid constructions. The result is equally valid for a timber door leaf in a timber frame mounted into a flexible construction with appropriate fixings for timber frames in flexible constructions.

2.9.5. Associated supporting constructions:
The fire resistance of a doorset tested along with an associated supporting construction is not valid for a change in the field of direct application.

3. Glazed Separating Elements

3.1. General

3.1.1. The results of the fire test on glazed separating elements when tested as per IS 16945 are directly applicable to similar constructions where one or more of the changes listed below are made. The resulting construction shall continue to comply with appropriate design code for its stiffness and stability.

a) Decrease in height;
b) Increase in thickness of the wall;
c) Increase in thickness of component materials;
d) Decrease in linear dimensions of boards or panels but not thickness; e) Decrease in stud spacing;
f) Decrease in distance of fixing centres;
g) Increase in the number of horizontal joints if the test specimen has a joint not more than 500 mm from the top edge;
h) The use of surface fittings and fixtures when the test specimen has the fixture or fitting not more than 500 mm from the top edge; and
j) Horizontal or vertical joints, of the type tested

3.2. Extension of Width of Vertical Elements

3.2.1. The width of an identical construction may be increased if the specimen was tested at a minimum of 3 m width with one vertical edge without restraint (free edge)

3.3. Extension of Height of Vertical Elements

3.3.1. The height of constructions tested at a minimum of 3 m, may be increased to 4 m under the following conditions:

a) If the maximum lateral deflection of the test specimen does not exceed 100 mm; and

b) The expansion allowances are increased pro-rata.

3.4. Supporting Constructions

3.4.1. Standard Supporting Constructions: The result of a fire test on a non-load bearing wall tested in one of the standard supporting constructions or the test frame will also apply to any other supporting construction within the same type which has a greater fire resistance.

3.4.2. Non-Standard Supporting Constructions: The result of a fire test on a non-load bearing wall tested in a non-standard supporting construction is applicable only to that particular construction.

3.5. Field of Direct Application - Limits of Permitted Size Variations

3.5.1. When the test specimen achieves overrun time A (Refer Table 3), the dimensions of the glass panes (width and/or height) can be increased upto 1.1 times of its tested dimension. However, the resultant area of the glass pane shall not be more than 1.1 times of the maximum tested area.

3.5.2. When the test specimen achieves overrun time B (Refer Table 3), the dimensions of the glass panes (width and/or height) can increased up to 1.2 times of its tested dimension. However, the resultant area of the glass pane shall not be more than 1.21 times of the maximum tested area.

3.5.3. For test specimens which are tested for integrity and radiation, the following provisions will apply additionally:

a) The average temperature of the unexposed face (both glazed and non-glazed area) remain below 300°C, or
b) The heat radiation measured from the complete and fully glazed element did not exceed 12.3 kW/m².

Table 3 Overrun time for the field of direct application of test results- limits of permitted size variations

4. References

4.1. IS 16945: 2018 Fire Resistance Test for Glass Walls.
4.2. IS 16947: 2018 Fire Resistance Tests for Doors with Glass Panes, Openable Glass Windows and Sliding Glass Doors.
4.3. IS 17518-1: 2022 Fire Resistance Tests- Doors and Shutter Assemblies Part 1: General Requirements.
4.4. IS/ISO 834-1: 1999 Fire Resistance Tests- Elements of Building Construction Part 1 General Requirements
4.5. ISO 3008-1: 2019 Fire Resistance Tests- Doors and Shutter Assemblies Part 1: General Requirements.
4.6. ISO 3009: 2003 Fire Resistance Tests- Elements of Building Construction- Glazed Elements.
4.7. EN 1363-1: 2020 Fire resistance tests - Part 1:

General requirements

4.8. EN 1363-2: 1999 Fire resistance tests - Part 2: Alternative and additional procedures
4.9. EN 1634-1: 2014 Fire resistance and smoke control tests for door and shutter assemblies, openable windows and elements of building hardware Part 1: Fire resistance test for door and shutter assemblies and openable windows.

- Reference document Afiti Global Fire Testing Private Limited.

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