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Variable actions: Imposed floor loads

The following table from BS EN 1991–1 gives the normally accepted minimum floor loadings.

Clients can consider sensible reductions in these loads if it will not compromise future flexibil-ity. A survey by Arup found that office loadings very rarely even exceed the values quoted for domestic properties.

The gross live load on columns and/or foundations from sections A to D in the table can be reduced in relation to the number of floors or floor area carried to BSEN 1991–1. Live load reductions are not permitted for loads from storage and/or plant, or where exact live loadings have been calculated.

Type of activity/

occupancy for part of the building

or structure Examples of specific use

Uniformity

A1 All usages within self-contained dwelling units (a unit occupied by a single family or a modular student accommodation unit with a secure door comprising not more than six single bedrooms and an internal corridor).

Communal areas (including kitchens) in blocks of flats with limited use (see Note a).

For communal areas in other blocks of flats, see A5, A6 and C3

1.5 2.0

A2 Bedrooms and dormitories except those in self-contained single family dwelling units and in hotels and motels

1.5 2.0

A3 Bedrooms in hotels and motels; hospital

wards; toilet areas 2.0 2.0

A4 Billiard/snooker rooms 2.0 2.7

Balconies

A5 Single family dwelling units and communal areas in blocks of flats with limited use (see Note a)

2.5 2.0

A6 Hostels, guest houses, residential clubs and communal areas in blocks of flats except those covered by Note a

Same as rooms to which they give access but with a A7 Hotels and motels Same as rooms to

which they give access but with a

areas B1 General use other than B2 2.5 2.7

B2 At or below ground floor level 3.0 2.7 C. Areas

C1 Areas with tables

C11 Public, institutional and communal dining rooms and lounges, cafes and restaurants (see Note b)

2.0 3.0

C12 Reading rooms with no book storage 2.5 4.0

C13 Classrooms 3.0 3.0

continued C2 Areas with fixed seats

(continued)

or structure Examples of specific use

Uniformity C21 Assembly areas with fixed seating (see

Note c) 4.0 3.6

C22 Places of worship 3.0 2.7

C3 Areas without obstacles for moving people C31 Corridors, hallways, aisles in institutional type buildings not subjected to crowds or wheeled vehicles, hostels, guest houses, residential clubs, and communal areas in blocks of flats not covered by Note a

3.0 4.5

C32 Stairs, landings in institutional type buildings not subjected to crowds or wheeled vehicles, hostels, guest houses, residential clubs, and communal areas in blocks of flats not covered by Note a

3.0 4.0

C33 Corridors, hallways, aisles in all buildings not covered by C31 and C32, including hotels and motels and in institutional type buildings subjected to crowds

4.0 4.5

C34 Corridors, hallways, aisles in all buildings not covered by C31 and C32, including hotels and motels and in institutional type buildings subjected to wheeled vehicles, including trolleys

5.0 4.5

C35 Stairs, landings in all buildings not covered by C31 and C32, including hotels and motels, and institutional buildings subjected to crowds

4.0 4.0

C36 Walkways – Light duty (access suitable for one person, walkway width approx.

600 mm)

3.0 2.0

C37 Walkways – General duty (regular

two-way pedestrian traffic) 5.0 3.6

C38 Walkways – Heavy duty (high-density pedestrian traffic including escape routes)

7.5 4.5

C39 Museum floors and art galleries for

exhibition purposes 4.0 4.5

C. Areas

C4 Areas with possible physical activities C41 Dance halls and studios, gymnasia,

stages (see Note e) 5.0 3.6

C42 Drill halls and drill rooms (see Note e) 5.0 7.0 C5 Areas susceptible to large crowds

C51 Assembly areas without fixed seating, concert halls, bars and places of worship (see Note d and Note e)

5.0 3.6

C52 Stages in public assembly areas (see

Note e) 7.5 4.5

(continued)

or structure Examples of specific use

Uniformity

areas D1 Areas in general retail shops 4.0 3.6

D2 Areas in department stores E1 Areas

E11 General areas for static equipment not specified elsewhere (institutional and public buildings)

2.0 1.8

E12 Reading rooms with book storage, e.g.

libraries 4.0 4.5

E13 General storage other than those specified (but designers are encouraged to determine project specific values)

2.4 per metre of storage height 7.0 E14 File rooms, filing and storage space

(offices) 5.0 4.5

E15 Stack rooms (books) 2.4 per metre of storage height (6.5 kN/m2 min)

7.0

E16 Paper storage for printing plants and

stationery stores 4.0 per metre of

storage height 9.0 E17 Dense mobile stacking (books) on

mobile trolleys, in public and institutional buildings

4.8 per metre of storage height (9.6 kN/m2 min)

7.0

E18 Dense mobile stacking (books) on

mobile trucks, in warehouses 4.8 per metre of storage height (15 kN/m2 min)

7.0

E19 Cold storage 5.0 per metre of

storage height

E201 Communal kitchens except those

covered by occupancy class A 3.0 4.5

E202 Operating theatres, x-ray rooms,

utility rooms 2.0 4.5

E203 Work rooms (light industrial) without

storage 2.5 1.8

E204 Kitchens, laundries, laboratories 3.0 4.5 E205 Rooms with mainframe computers or

similar equipment 3.5 4.5

E206 Machinery halls, circulation spaces

therein 4.0 4.5

E207 Cinematographic projection rooms 5.0 To be determined for specific use E208 Factories, workshops and similar

buildings (general industrial) 5.0 4.5

E209 Foundries 20.0 To be

determined for specific use

continued

(continued)

or structure Examples of specific use

Uniformity E211 Fly galleries (i.e. access structures

used in theatres to hang scenery, curtains, etc.)

4.5 kN/m –

E212 Ladders – 1.5 rung

load E213 Plant rooms, boiler rooms, fan rooms,

etc., including weight of machinery 7.5 4.5 F. Traffic areas F Traffic areas vehicle weight ≤30 kN 2.5 9.0 G. Traffic

areas G Traffic areas

30 kN < vehicle weight ≤160 kN 5.0 To be

determined for specific use H. Roofs H Roofs not accessible except for normal

maintenance and repair 0.6 0.9

I. Roofs I Roofs accessible – occupancy according to

categories A to G As category As category

K. Roofs K Roofs accessible for special services, such

as helicopter landing areas To be determined for specific use To be

determined for specific use Notes:

a Communal areas in blocks of flats with limited are blocks of flats not more than three storeys in height and with not more than four self-contained dwelling units per floor accessible from one staircase.

b Where the areas described by C11 might be subjected to loads due to physical activities or overcrowding, e.g. a hotel dining room used as a dance floor, imposed loads should be based on occupancy C4 or C5 as appropriate. Reference should also be made to Note e.

c. Fixed seating is seating where its removal and use of the space for other purposes is improbable.

d For grandstands and stadia, reference should be made to the requirements of the appropriate certifying authority.

e For structures that might be susceptible to resonance effects, reference should be made to NA2.1.

f Museums, galleries and exhibition spaces often need more capacity than this, sometimes up to 10 kN/m2.

Source: NA to BS EN 1991-1-1:2002, Tables NA.2, NA.3, NA.4, NA.5, NA.6, NA.7 BS EN 1991-1-1:2002, Table 6.9. PD 6688 1-1:2011, Table 1.

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