Approved Document B 2019 – What are the requirements for roofs and balconies?

17 December 2019 Kingspan Insulation UK
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Approved Document B to the Building Regulations in England (ADB-2019) received a significant update in July 2019 and this means there are new fire safety requirements for projects which began after the 30th August 2019. In a previous article, we looked at the changes relating to external wall constructions on high rise buildings , now we will highlight what’s new for roofs and balconies.

Balconies and other “specified attachments”

As we discussed previously, Regulation 7(4) now identifies so called ‘relevant buildings’. These are properties with a storey at least 18 metres above ground level which contain:
•    one or more dwelling;
•    an institution; or
•    a room for residential purposes (excluding any room in hostels, hotels or boarding houses). 

The regulation states that “specified attachments” to the walls (aside from specific exemptions stated in Regulation 7(3)) must now achieve a European Classification (Euroclass) of at least A2-s1,d0. These specified attachments are defined in Regulation 2 and include balconies (an attachment to a wall, unheated on both sides), also including attached and inset balconies. It is important to note that this may not apply to roof terraces or other roofs with a heated space below, subject to interpretation by your local Building Control.  See the next section for information on those areas. 

Additional advice on the requirements for projecting balconies for multi-residential buildings is available within an advice note from the Ministry of Housing, Communities & Local Government.

Roofs and roof terraces

It is Kingspan Insulation’s interpretation that most roofs and roof terraces are unaffected by the requirements of Regulation 7(2-4). As previously stated, this is subject to the interpretation of your local Building Control and before undertaking work on any such project further guidance should be sort from your local Building Control office.

The only exception is those identified within paragraph (iv) of Regulation 2(6) which include areas with pitches above 70 degrees to the horizontal and which are accessible from within the building for purposes other than maintenance.

For all other roofs, the coverings must meet the requirements in Table 14.1 of ADB-2019. Roof systems with the inorganic covering materials listed below* are considered to meet external fire requirements without the need for testing:
•    loose laid gravel ≥ 50 mm or ≥ 80 kgm² (size 4-32 mm);
•    sand/cement screed ≥ 30 mm; or
•    cast stone/mineral slabs ≥ 40 mm.
 
*per Commission Decision 2000/553/EC of 6th of September 2000, implementing Council Directive 89/106/ECC.

Alternatively, the roof system should be classified to BS EN 13501-5: 2016. This standard provides criteria which roof systems must meet when tested under the methods within CEN/TS 1187. These tests use burning brands, wind (fans) and supplementary radiant heat, and can be used to assess:
•    external surface fire spread; 
•    fire spread within the roof;
•    fire penetration; and
•    the production of flaming droplets or debris falling from the underside of the roof of the exposed surface.

Roof systems are classified into five categories within BS EN 13051-5: 2016 from BROOF(t4) (highest performance) to FROOF(t4) (lowest performance). The table below outlines where different system classifications can be used. 

Designation of covering of roof or part of roof Distance from any point on relevant boundary
Less than 6 m At least 6 m At least 12 m At least 20 m
BROOF(t4)
CROOF(t4)
DROOF(t4) (1)(2) (1)
EROOF(t4) (1)(2) (1) (1)
FROOF(t4) (1)(2)

1. Not acceptable on any of the following buildings.
a. Industrial, storage or other non–residential purpose group (purpose groups 6 and 7)
buildings of any size.
b. Any other buildings with a cubic capacity of more than 1500 m3.

2. Acceptable on buildings not listed in (1) if both of the following apply.
a. Part of the roof has a maximum area of 3 m2 and is a minimum of 1500 mm from any
similar part.
b. The roof between the parts is covered with a material rated class A2-s3,d2 or better.


Where can Kingspan’s insulation products be used on roofs?

We offer a wide range of insulation products for flat roofs, roof terraces and pitched roofs

These products are suitable for use in applications beneath the inorganic covering materials outlined above. In addition, the products have been classified as part of a range of common build-ups to BS EN 13501-5. As the test method involves the insulation in end–use application, testing is typically carried out by the waterproofing manufacturer for the system or build–up. The products cannot be used as part of balconies defined as ‘specified attachments’ for ‘relevant buildings’ within the Building Regulations.

For more information about the new requirements within ADB 2019, download our technical bulletin  and keep an eye on our #FireSafetyMatters page
 

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