TABLE 3.3A: Minimum Periods of Fire Resistance

Note to Part I:

For the purpose of Cl 3.3.2 the period of fire resistance to be taken as being relevant to an element of structure is the period included in columns (5) or (6) in the line of entries which specifies the floor area with which there is conformity or, if there are two or more such lines, in the topmost of those lines
(*) - A floor which is immediately over a basement storey shall be deemed to be an element of structure forming part of a basement storey.
(**) - Height for elements of structure referred to building height including basement. In the case of compartment wall/external wall, the height shall be based on the height of the wall between compartment floors.
⁽⁺⁾ - The expression “part” means a part which is separated as described in Cl.3.3.1b..
(a) - This period is reduced to 2-hrs for:

(1) non-sprinkler-protected, open-sided standalone car park buildings
(2) sprinkler-protected, above-ground car park floors in standalone car park building or sprinkler- protected mixed-use building

(b) - Single basement car park storey, which is sprinkler-protected, the element of structure can be reduced to half the minimum period of fire resistance

PG I - Small residential

NL

1

PG II - Other residential

NL

1

PG III - Institutional

NL

1

PG IV - Office

NL

1

PG V - Shop

3000

1

NL

2

PG VI - Factory

3000

1

NL

2

PG VII - Place of public resort

3000

1

NL

2

PG VIII - Storage and general

1000

1

3000

2

NL

4^(a)

Note to Part 2:

For the purpose of Cl.3.3.2 the period of fire resistance to be taken as being relevant to an element of structure is the period included in column (3) in the line of entries which specifies the floor area with which there is conformity or, if there are two or more such lines, in the topmost of those lines

^(a) - This period is reduced to 2-hr for open-sided buildings which are used solely for car parking

Less than 15m

Non-compartment

1-hr or less

Surface of ceiling exposed within the cavity not lower than Class I surface flame spread rating.

Compartment

Less than 1-hr

Compartment

1-hr

Surface of ceiling exposed within the cavity not lower than Class 0 surface flame spread rating; supports and fixing for the ceiling non-combustible.

Any

More than 1-hr

Ceiling of non-combustible con- struction and jointless; supports and fixings for the ceiling non- combustible.

15m or more

Any

1-hr or less

Surface of ceiling exposed within the cavity not lower than Class 0 surface flame spread rating and jointless; supports and fixing for the ceiling non-combustible.

Any

More than 1-hr

Ceiling of non-combustible con- struction and jointless; supports and fixings for the ceiling non- combustible

Note:

References to classes in the above table are to classes as specified in Cl.3.13

Where the space above a suspended ceiling is protected by an automatic sprinkler system it shall be exempted from the requirements for non-combustibility and surface spread of flame classification as specified in the above table provided the ceiling is not situated over an exit passageway, protected lobby or other required protected means of escape

*

(min. 60)

*

(min. 60)

*

(min. 60)

⁺

(min. 60)

**

(min. 30)

Modifications

⁺⁺ - No provision for insulation if the casing is more than 50mm from any pipe in the enclosure (except a pipe passing through the casing)

Note:

* - Period of fire resistance as specified

** - Half the period of fire resistance for the wall or floor in which the door is situated

*** = This exemption does not apply to fire-rated glass door.

⁺ - Period of fire resistance for the wall or floor in which the door is situated
⁺⁺ - No provision for insulation if the casing is more than 50mm from any pipe in the enclosure (except a pipe passing through the casing)
 1 - A suspended ceiling should only be relied on to contribute to the fire resistance of the floor if the ceiling meets the appropriate provisions given in Table 3.3B

2 - Any part of the wall which is 7.5m or less above the ground, or above a roof or any other part of the building to which people have access, if the building has 2 or more storeys

When the pipes (include pipe supports) penetrate the structure enclosing a protected shaft which is not an exit stairway or lift shaft

150

100

40

Any other situation

150

100 (stack pipe) ^(3),(4),(5)

75 (branch pipe) ^(3),(4),(5)

40

Note:

(1) =  A non-combustible material (such as for cast iron or steel pipes and the pipe supports with melting point of at least 1200°C) which if exposed to a temperature of 750°C will not soften nor fracture to the extent that flame or gases will pass through the wall of the pipe

(2) = UPVC pipes complying with BS 4514 or EN 1329-1

(3) = Within toilets, washrooms or external corridors, maximum diameter of UPVC pipes can be increased to double the size given in the above table

(4) = Within areas of fire risk, such as kitchens, and adjacent to escape routes, UPVC pipes shall be enclosed by construction having fire resistance rating of at least ½ hr

(5) = Where the size of UPVC pipes exceeds that specified under this clause, approved fire collar shall be fitted at all positions where such pipes pass through constructions required to act as a barrier to fire spread

Between roof and ceiling

I & II

any

no limit

others

any

20m

Any other cavity

any

Class 0

20m⁺

any

any

8m⁺

Note:

* - excluding surface of any pipe, cable, conduit or insulation of any pipe

⁺ - shall not apply to raised floor under Cl.3.11.8

PG I - Small residential

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

2

C

0

B

PG II - Other residential

NA

NA

0

B

0

B

NC

A2

NA

NA

NA

NA

2

C

0

B

PG III - Institutional

1

C

0

B

0

B

NC

A2

3

D⁽¹⁾

3

D⁽¹⁾

2

C

0

B

PG IV - Office

1

C

0

B

0

B

NC

A2

NA

NA

NA

NA

2

C

0

B

PG V - Shop

1

C

0

B

0

B

NC

A2

NA

NA

NA

NA

2

C

0

B

PG VI - Factory

1

C

0

B

0

B

NC

A2

NA

NA

NA

NA

2

C

0

B

PG VII - Place of public resort

1

C

0

B

0

B

NC

A2

NA

NA

NA

NA

2

C

0

B

PG VIII - Storage

1

C

0

B

0

B

NC

A2

NA

NA

NA

NA

2

C

0

B

Note:

NC = Non-combustible to comply with BS 476 Pt 4

NA = Not Applicable

(1) = Applies to detention facilities and healthcare, including hospital, old-aged homes, nursing homes for mentally or physically disabled patients

(2) = BS/ EN refers to the following test standards. Meeting an EN standard implies that the corresponding BS standard is complied with but not vice-versa

PG I - Small residential

NA

NA

NA

NA

NA⁽²⁾

NA⁽²⁾

NA

NA

NA

NA

NA

NA

PG II - Other residential

NA

NA

LC⁽³⁾

A2

NA⁽²⁾

NA⁽²⁾

NA

NA

1

C

NA

NA

PG III - Institutional

0

B

LC⁽³⁾

A2

1

C⁽⁴⁾

1

C⁽¹⁾

0

B⁽¹⁾

2

C⁽¹⁾⁽⁴⁾

PG IV - Office

0

B

LC⁽³⁾

A2

1

C⁽⁴⁾

2

C

1

C

2

C⁽⁴⁾

PG V - Shop

0

B

LC⁽³⁾

A2

1

C⁽⁴⁾

2

C

1

C

2

C⁽⁴⁾

PG VI - Factory

0

B

LC⁽³⁾

A2

1

C⁽⁴⁾

2

C

1

C

2

C⁽⁴⁾

PG VII - Place of public resort

0

B

LC⁽³⁾

A2

1

C⁽⁴⁾

2

C

1

C

2

C⁽⁴⁾

PG VIII - Storage

0

B

LC⁽³⁾

A2

1

C⁽⁴⁾

2

C

1

C

2

C⁽⁴⁾

Note:

(1)  =  Applies to detention facilities and healthcare, including hospital, nursing homes for handicapped, disabled, aged or persons with mental and/ or mobility impairment

(2) = Roof support can be of timber construction. Any use of plastic material for roof shall comply with the requirements in Cl.3.15.19c.(8)

(3) = Limited combustibility tested under BS 476 Part 11 or non-combustibility tested under BS 476 Part 4

(4) =  Composite panel complying with ASTM E108 Class A is also acceptable

(5) = Applicable to composite panel roofing only. Refer to Cl.3.14.1 for other roofing materials

(6) = Including common corridor, passageway etc.

(7) = BS/EN refers to the test standards shown in the Note to Table 3.13A. Meeting an EN standard implies that the corresponding BS standard is com- plied with but not vice-versa

NA = Not Applicable

LC = Limited combustibility

* = When composite panels are used for the construction, the minimum flame-spread classification shall be applicable to the core material of the panels

1

Non-combustible material

Allowed

No further fire test is required

2

Material thickness not exceeding 10mm

Allowed

1. No further fire test is required

2. For sprinkler-protected premises, material not exceeding 20mm can be exempted from the tests in Table 3.15A

3

Use in open-to-sky conditions

Allowed

No further fire test is required

4

Use in exit staircase/ exit passageways

Not allowed

Key escape routes shall be protected

Material thickness exceeding 10mm

Allowed with conditions

Allowed if pass test categories A, B and C in Table 3.15A

1

Non-combustible material

Allowed

No further fire test is required

2

Material thickness not exceeding 10mm

Allowed

1. No further fire test is required

2. For sprinkler-protected premises, material not exceeding 20mm can be exempted from the tests in Table 3.15A

3

Use in open-to-sky conditions

Allowed

No further fire test is required

4

Use in exit staircase/exit passageways

Not allowed

Key escape routes shall be protected

5

Material thickness exceeding 10mm

Allowed with conditions

1. If masonry cover is less than 25mm thick, the material shall pass test categories A, B and C in Table 3.15A.

2. If masonry cover is at least 25mm thick all around the embedded plastic, tests in Table 3.15A are exempted.

3. The locations where embedded plastics are installed shall be clearly indicated on the plans

1

Non-combustible material

Allowed

No further fire test is required

2

Material thickness not exceeding 10mm

Allowed

1. No further fire test is required

2. For sprinkler-protected premises, material not exceeding 20mm can be exempted from the tests in Table 3.15A

3

Use in open-to-sky conditions.

Allowed

No further fire test is required

Use in exit staircase / exit passageways

Not allowed

Key escape routes shall be protected

5

Material thickness exceeding 10mm

Allowed with conditions

1. Allowed if pass test categories A, B and C in Table 3.15A

2. If the overlay is non-combustible and at least 25mm thick, test category C in Table 3.15A is exempted

1

Non-combustible material

Allowed

No further fire test required

Material thickness not exceeding 1mm

Allowed

No further fire test required

3

Use in exit staircase/exit passageways

Not allowed

Key escape routes shall be protected

4

Material thickness exceeding 1mm

Allowed with conditions

Allowed if pass test categories D, E and F in Table 3.15B, unless specifically exempted for external building applications

1

Non-combustible plastic material

Allowed

No further fire test required

2

Plastic material thickness not exceeding 1mm

Allowed

No further fire test required

3

Use in exit staircase/ exit passageways

Not allowed

Key escape routes shall be protected

4

Plastic material thickness exceeding 1mm

Allowed with conditions

Allowed if pass test categories D, E and F in Table 3.15B, unless specifically exempted for external building applications

1

Non-combustible material

Allowed

No further fire test required

2

Material thickness not exceeding 1mm

Allowed

No further fire test required

3

Use in exit staircase/ exit passageways

Not allowed

Key escape routes shall be protected

Material thickness exceeding 1mm

Allowed with conditions

1. If masonry cover is less than 25mm thick, the material shall pass test categories D, E and F in Table 3.15B

2. If masonry cover is at least 25mm thick all around the embedded plastic, tests in Table 3.15B are exempted

3. The locations where embedded plastics are installed shall be clearly indicated on the plans

1

Non-combustible material

Allowed

No further fire test required

2

Material thickness not exceeding 1mm

Allowed

No further fire test required

3

Use in exit staircase/ exit passageways

Not allowed

Key escape routes shall be protected

4

Material thickness exceeding 1mm

Allowed with conditions

1. Allowed if  pass  test  category J in Table 3.15C, as well as test category H in Table 3.15C if exposed on underside

2. Exempted from test categories H and if the requirements specified for skylights in Cl.3.13.5b.

1

Non-combustible plastic material

Allowed

No further fire test required

2

Plastic material thickness not exceeding 1mm

Allowed

No further fire test required

3

Use in exit staircase/ exit passageways

Not allowed

Key escape routes shall be protected

4

Plastic material thickness exceeding 1mm

Allowed with conditions

1. Allowed if pass  test  category J in Table 3.15C, as well as test category H in Table 3.15C if exposed on underside

2. Exempted from test categories H and J if the requirements specified for skylights in Cl.3.13.5b.