Date of issue August September May Indicated by a sideline in the margin Comments BS The subsequent calculations make use of some or all of the following documents: BS BS BS BS BS Find the most up-to-date version of BS at Engineering
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In some transport of snow from one side of the ridge to the circumstances more than one of the load cases will other side. Code of practice for imposed roof loads Licensed Copy: The snow loads should be 6399-33 according to clause 7.
General 1 Scope 2. Want access to British Standards? Snow loads 5 Snow load on the roof 4 6 Snow load on the ground 4 7 Snow load shape coefficients 6 8 Snow sliding down roofs 9 Appendix A Annual probabilities of exceedance different from 0.
This British Standard applies to: The treatment of snow drifting against obstructions in section two is similar to that given in BRE Digestissued in Octoberbut now withdrawn. BRE DigestLoads on roofs from snow drifting against vertical obstructions ba in valleys2. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards.
It is not intended for use in calculating snow load shape coefficients. This results from a uniform layer of snow over the complete roof. It is not necessary to make any correction for the height of the building.
However, as an approximate rule, it is only necessary to consider nearby structures when they are hs b3 should be taken as the horizontal dimension of than 1.
In general, load cases should be considered to act individually and not together. NOTE The titles of the publications referred to in this code are 2. The type and record length of the ground snow data available and the paucity of observational data on roof snow loads make it extremely difficult to estimate snow load distributions reliably. However, a lower probability of exceedance should be considered for the design 6399–3 Belfast The address of the advisory service of the Building Research Establishment is as follows.
BSWind loads. These are flat, monopitch, pitched or surrounding roofs or obstructions.
BS _Loading for building-Part3 Imposed roof loads_图文_百度文库
Providing the above conditions are met, an allowance should be made for an imposed load equal to or greater than that which produces the worst load effect from one of the following: If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained.
Standard Number BS Customers vs bought this product also bought BS EN Code of practice for imposed roof loads Status: For intersecting pitched roofs the snow load shape coefficients and the drift lengths should be obtained from Figure 8. These include local shelter from the wind, which may result in increased local snow loads, and local configurations in mountainous areas, which may funnel the snow 3699-3 give increased local loading.
The factor is usually 5 or 8 depending upon the severity of drifting likely to occur for the design configuration being considered. Several snow load cases may have to be considered in design to check adequately for the different snow load patterns that can occur.
A relatively tall, The appropriate value for sd is obtained from slender obstruction over 1 m high but not more clause 5. ISOBases for design of structures — Determination of snow loads on roofs1. This subclause is an optional alternative to 4. Various BSI electronic information services are also available which give details on all its products and services.
Users of British Standards should make sure that 639-3 possess the latest amendments or editions. It is incorporated by Royal Charter. Redistribution of snow should be considered to occur on any roof slope and at any obstruction, as it should be assumed that the wind can blow from any direction.
In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested. NOTE The snow load shape coefficient, being a ratio of two loads, is non-dimensional.
If the designer suspects that there may be unusual local conditions that may need to be taken into account, then the Meteorological Office or informed local sources should be consulted. Your basket is empty. Caution is necessary in applying the snow load 639-3 for sites at altitudes above m and specialist advice should be obtained in such situations see appendix C. Amendment 2 has been issued to address problems encountered with use. For these roofs it is necessary to consider a single load case resulting from a uniform layer of snow over the complete roof.
The value for the snow load shape coefficient for one side of the roof should be zero, i. Buying standards Orders for all 3699-3, international and foreign standards publications should be addressed to Customer Services.
NOTE The sopleths in Figure 1 are derived from analysis of data from a limited number of recording stations and therefore unusual local effects may not be included.
Snow is treated specifically in this code while the minimum imposed roof a vertical load on a given area in plan of varying load value allows for loads resulting from rain, ice and local load intensity temperature.
Snow load shape coefficient? A relatively tall, slender obstruction over 1 m high but not more than 2 m wide, may also be considered as a local projection.
ISOBases for design of structures — Determination of snow loads on roofs1. This document Newer versions. Where site snow loads with a probability of exceedance different from 0.
In the direction applies where there is an abrupt change of height parallel to the obstruction or valley it should be greater than 1 m, except that relatively slender uniform and assumed to extend along the complete obstructions e. The primary loading conditions to be considered are: These loads assume that spreader boards will be used while any cleaning or maintenance work is in progress on fragile roofs.
Snow loads 5 Snow load on the roof 6 Snow load on the ground 7 Snow load shape coefficients 8 Snow sliding down roofs Appendix A Annual probabilities of exceedance different from 0.