Section 14 Roof coverings

Roof coverings

  1. Introduction
    1. Other controls on roofs
    2. Classification of performance
      1. Separation distances
        1. Plastic rooflights
          1. Unwired glass in rooflights
            1. Thatch and wood shingles

            Introduction

            14.1The provisions in this section limit the use, near a boundary, of roof coverings which will not give adequate protection against the spread of fire over them. The term roof covering is used to describe constructions which may consist of one or more layers of material, but does not refer to the roof structure as a whole. The provisions in this Section are principally concerned with the performance of roofs when exposed to fire from the outside.

            14.2The circumstances when a roof is subject to the provisions in Section 13 for space separation are explained in paragraph 13.1.

            Other controls on roofs

            14.3There are provisions concerning the fire properties of roofs in three other Sections of this document. In the guidance to B1 (paragraph 5.3) there are provisions for roofs that are part of a means of escape. In the guidance to B2 (paragraph 6.12) there are provisions for the internal surfaces of rooflights as part of the internal lining of a room or circulation space. In the guidance to B3 there are provisions in Section 7 for roofs which are used as a floor and in Section 8 for roofs that pass over the top of a compartment wall.

            Classification of performance

            14.4The performance of roof coverings is designated by reference to the test methods specified in BS 476-3: 2004 or determined in accordance with BS EN 13501-5:2005, as described in Appendix A. The notional performance of some common roof coverings is given in Table A5 of Appendix A.

            Rooflights are controlled on a similar basis and plastic rooflights described in paragraph 14.6 and 14.7 may also be used.

            Separation distances

            Diagram 47

            14.5The separation distance is the minimum distance from the roof (or part of the roof) to the relevant boundary, which may be a notional boundary.

            Table 16 sets out separation distances according to the type of roof covering and the size and use of the building. There are no restrictions on the use of roof coverings designated AA, AB or AC (National class) or BROOF(t4) (European class) classification. In addition, roof covering products (and/or materials) as defined in Commission Decision 2000/553/EC of 6th September 2000 implementing Council Directive 89/106/EEC as regards the external fire performance of roof coverings can be considered to fulfil all of the requirements for performance characteristic "external fire performance" without the need for testing provided that any national provisions on the design and execution of works are fulfilled. That is, the roof covering products (and/ or materials) defined in this Commission Decision can be used without restriction.

            Plastic rooflights

            14.6Table 17 sets out the limitations on the use of plastic rooflights which have at least a Class 3 (National class) or Class D-s3, d2 (European class) lower surface and Table 18 sets out the limitations on the use of thermoplastic materials with a TP(a) rigid or TP(b) classification (see also Diagram 47). The method of classifying thermoplastic materials is given in Appendix A.

            14.7When used in rooflights, a rigid thermoplastic sheet product made from polycarbonate or from unplasticised PVC, which achieves a Class 1 (National class) rating for surface spread of flame when tested to BS 476-7:1971 (or 1987 or 1997) Surface spread of flame tests for materials, or Class C-s3, d2 (European class) can be regarded as having an AA (National class) designation or BROOF(t4) (European class) classification, other than for the purposes of Diagram 30.

            Unwired glass in rooflights

            14.8When used in rooflights, unwired glass at least 4mm thick can be regarded as having an AA designation (National class) designation or BROOF(t4) (European class) classification.

            Thatch and wood shingles

            Table 16

            14.9Thatch and wood shingles should be regarded as having an AD/BD/CD designation or EROOF(t4) (European class) classification in Table 16 if performance under BS 476-3: 1958 2004 or EN 1187:XXX (test 4) respectively cannot be established.

            • 1 Gallery floors with no alternative exit Diagram 1 Gallery floors with no alternative exit
            • 2 Flat where all habitable rooms have direct access to an entrance hall Diagram 2 Flat where all habitable rooms have direct access to an entrance hall
            • 3 Flat with restricted travel distance from furthest point to entrance Diagram 3 Flat with restricted travel distance from furthest point to entrance
            • 4 Flat with an alternative exit but where all habitable rooms have no direct acess to an entrance hall Diagram 4 Flat with an alternative exit but where all habitable rooms have no direct access to an entrance hall
            • 5 Multi-storey flat with alternative exits from each habitable room except at entrance level 5 Multi-storey flat with alternative exits from each habitable room except at entrance level
            • 6 Multi-storey flat with protected entrance hall and landing Diagram 6 Multi-storey flat with protected entrance hall and landing
            • 7 Flats served by one common stair,png Diagram 7 Flats served by one common stair
            • 8 Flats served by more than one common stair 8 Flats served by more than one common stair
            • 9 Common escape route in small single stair building Diagram 9 Common escape route in small single stair building
            • 10 Travel distance in dead-end condition 10 Travel distance in dead-end condition
            • 11 Alternative escape routes 11 Alternative escape routes
            • 12 Inner room and access room 12 Inner room and access room
            • 13 Exits in a central core Diagram 13 Exits in a central core
            • 14 Open Connections Diagram 14 Open Connections
            • 15 Merging flows at final exit Diagram 15 Merging flows at final exit
            • 16 Subdivision of corridors Diagram 16 Subdivision of corridors
            • 17 Dead-end corridors Diagram 17 Dead-end corridors
            • 18 Maximum travel distances in a small two or three storey premises with a single protected stair to each storey Diagram 18 Maximum travel distances in a small two or three storey premises with a single protected stair to each storey
            • 19 Progressive horizontal evacuation in care homes Diagram 19 Progressive horizontal evacuation in care homes
            • 20 Refuge formed by compartmentation Diagram 20 Refuge formed by compartmentation
            • 21 Refuge formed in a protected stairway Diagram 21 Refuge formed in a protected stairway
            • 22 Max travel distance in a small three storey premises with a single stair to each storey Diagram 22 Max travel distance in a small three storey premises with a single stair to each storey
            • 23 Max travel distance in a small two storey premises with a single open stair Diagram 23 Max travel distance in a small two storey premises with a single open stair
            • 24 External protection to protected stairways Diagram 24 External protection to protected stairways
            • 25 Fire resistance of areas adjacent to external stairs 25 Fire resistance of areas adjacent to external stairs
            • 26 Lighting diffuser in relation to ceiling Diagram 26 Lighting diffuser in relation to ceiling
            • 27 Layout restrictions on Class 3 plastic roofflights TP-b rooflights and TP b lighting diffusers Diagram 27 Layout restrictions on Class 3 plastic rooflights TP-b rooflights and TP b lighting diffusers
            • 27a Layout restrictions on small Class 3 plastic rooflights TP b rooflights and lighting diffusers Diagram 27a Layout restrictions on small Class 3 plastic rooflights TP b rooflights and lighting diffusers
            • 28 Compartment floors illustration of guidance in paragraph 8.16 Diagram 28 Compartment floors illustration of guidance in paragraph 8.16
            • 29 Compartment walls and compartment floors with reference to relevant paragraphs in Section 8 Diagram 29 Compartment walls and compartment floors with reference to relevant paragraphs in Section 8
            • 30 Junction of compartment wall with roof Diagram 30 Junction of compartment wall with roof
            • 31 Protected shafts Diagram 31 Protected shafts
            • 32 Uninsulated glazed screen separating protected shaft from lobby or corridor Diagram 32 Uninsulated glazed screen separating protected shaft from lobby or corridor
            • 33 Provisions for cavity barriers Diagram 33 Provisions for cavity barriers
            • 34 Cavity wall excluded from provisions for cavity barriers Diagram 34 Cavity wall excluded from provisions for cavity barriers
            • 35 Fire-resisting ceiling below concealed space Diagram 35 Fire-resisting ceiling below concealed space
            • 36 Provisions for cavity barriers in double-skinned insulated roof sheeting Diagram 36 Provisions for cavity barriers in double-skinned insulated roof sheeting
            • 37 Pipes penetrating structure Diagram 37 Pipes penetrating structure
            • 38 Enclosure for drainage or water supply pipes Diagram 38 Enclosure for drainage or water supply pipes
            • 39 Flues penetrating compartment walls or floors Diagram 39 Flues penetrating compartment walls or floors
            • 40 Provisions for external surfaces or walls Diagram 40 Provisions for external surfaces or walls
            • 41 Relevant boundary Diagram 41 Relevant boundary
            • 42 Notional boundary Diagram 42 Notional boundary
            • 43 Status of combustible surface material as unprotected area Diagram 43 Status of combustible surface material as unprotected area
            • 44 Unprotected areas which may be disregarded in assessing the separation distance from the boundary Diagram 44 Unprotected areas which may be disregarded in assessing the separation distance from the boundary
            • 45 The effect of a canopy on separation distance Diagram 45 The effect of a canopy on separation distance
            • 46 Permitted unprotected areas in small residential buildings Diagram 46 Permitted unprotected areas in small residential buildings
            • 47 Limitations on spacing and size of plastic rooflights having a Class 3 or Class D-s3 d2 or TP b lower surface Diagram 47 Limitations on spacing and size of plastic rooflights having a Class 3 or Class D-s3 d2 or TP b lower surface
            • 48 Example of building footprint and perimeter Diagram 48 Example of building footprint and perimeter
            • 49 Relationship between buildings and hardstanding access roads for high reach fire appliances Diagram 49 Relationship between buildings and hardstanding access roads for high reach fire appliances
            • 50 Turning facilities Diagram 50 Turning facilities
            • 51 Provision of firefighting shafts Diagram 51 Provision of firefighting shafts
            • 52 Components of a firefighting shaft Diagram 52 Components of a firefighting shaft
            • 53 Fire-resisting construction for smoke outlet shafts Diagram 53 Fire-resisting construction for smoke outlet shafts
            • C1 Measurement of door width Diagram C1 Measurement of door width
            • C2 Cubic capacity Diagram C2 Cubic capacity
            • C3 Area Diagram C3 Area
            • C4 Height of building Diagram C4 Height of building
            • C5 Number of storeys Diagram C5 Number of storeys
            • C6 Height of top storey in buildingC6 Height of top storey in building Diagram C6 Height of top storey in building
            • C7 Free area of smoke ventilators Diagram C7 Free area of smoke ventilators
            • D1 Classification of Purpose Groups Diagram D1 Classification of Purpose Groups
            • E1 Recessed car parking areas Diagram E1 Recessed car parking areas
            • Table 1 Limitations on distance of travel in common areas of blocks of flats - see par 2.23 Table 1 Limitations on distance of travel in common areas of blocks of flats - see par 2.23
            • Table 2 Limitations on travel distance Table 2 Limitations on travel distance
            • Table 3 Minimum number of escape routes and exits from a room tier or storey Table 3 Minimum number of escape routes and exits from a room tier or storey
            • Table 4 Widths of escape routes and exits Table 4 Widths of escape routes and exits
            • Table 5 Maximum distances of travel in small premises with a protected stair Table 5 Maximum distances of travel in small premises with a protected stair
            • Table 6 Minimum widths of escape stairs Table 6 Minimum widths of escape stairs
            • Table 7 Capacity of a stair for basements and for simultaneous evacuation of the building Table 7 Capacity of a stair for basements and for simultaneous evacuation of the building
            • Table 8 Minimum width of stairs designed for phased evacuation Table 8 Minimum width of stairs designed for phased evacuation
            • Table 9 Provisions for escape lighting Table 9 Provisions for escape lighting
            • Table 10 Classification of linings Table 10 Classification of linings
            • Table 11 Limitations applied to thermoplastic rooflights and lighting diffusers in suspended ceilings and Class 3 plastic rooflights Table 11 Limitations applied to thermoplastic rooflights and lighting diffusers in suspended ceilings and Class 3 plastic rooflights
            • Table 12 Maximum dimensions of building or compartment - non-residential buildings Table 12 Maximum dimensions of building or compartment - non-residential buildings
            • Table 13 Maximum dimensions of cavities in non-domestic buildings - purpose Groups 2-7 Table 13 Maximum dimensions of cavities in non-domestic buildings - purpose Groups 2-7
            • Table 14 Maximum nominal internal diameter of pipes passing through a compartment wall-floor - see par 10.5 onwards Table 14 Maximum nominal internal diameter of pipes passing through a compartment wall-floor - see par 10.5 onwards
            • Table 15 Permitted unprotected areas in small buildings or compartments Table 15 Permitted unprotected areas in small buildings or compartments
            • Table 16 Limitations on roof coverings Table 16 Limitations on roof coverings
            • Table 17 Class 3 or Class D-s3 d2 plastic rooflights limitations on use and boundary distance Table 17 Class 3 or Class D-s3 d2 plastic rooflights limitations on use and boundary distance
            • Table 18 TP a and TP b plastic rooflights limitations on use and boundary distance Table 18 TP a and TP b plastic rooflights limitations on use and boundary distance
            • Table 19 Fire and rescue service vehicle access to buildings excluding blocks of flats not fitted with fire mains Table 19 Fire and rescue service vehicle access to buildings excluding blocks of flats not fitted with fire mains
            • Table 20 Typical fire and rescue service vehicle access route specification Table 20 Typical fire and rescue service vehicle access route specification
            • Table A1 Specific provisions of test for fire resistance of elements of structure etc Table A1 Specific provisions of test for fire resistance of elements of structure etc
            • Table A1 continued Table A1 continued
            • Table A2 Minimum periods of fire resistance Table A2 Minimum periods of fire resistance
            • Table A3 Limitations on fire-protecting suspended ceilings - see Table A1 Note 4 Table A3 Limitations on fire-protecting suspended ceilings (see Table A1 Note 4)
            • Table A4 Limitations on the use of uninsulated glazed elements on escape routes Table A4 Limitations on the use of uninsulated glazed elements on escape routes]
            • Table A5 Notional designations of roof coverings Table A5 Notional designations of roof coverings
            • Table A6 Use and definitions of non-combustible materials Table A6 Use and definitions of non-combustible materials
            • Table A7 Use and definitions of materials of limited combustibility Table A7 Use and definitions of materials of limited combustibility
            • Table A8 Typical performance rating of some generic materials and products Table A8 Typical performance rating of some generic materials and products
            • Table B1 Provisions for fire doors Table B1 Provisions for fire doors
            • Table C1 Floor space factors Table C1 Floor space factors
            • Table D1 Classification of Purpose Groups Table D1 Classification of Purpose Groups
            • Table Maximum dimensions of building or compartment - non-residential buildings Table Maximum dimensions of building or compartment (non-residential buildings)