BS 6093:1993 pdf free download.Code of practice for Design of ioints and jointing in building construction.
1 Scope
BS 6093 gives recommendations for the design of joints and the use of jointing products in building construction. Following an analysis of joint functions and of the performance of the parts to be joined, joints are classified in this standard on the basis of the movements and inaccuracies they have to accommodate. Mechanisms by which joints operate are identified and recommendations are made on the use of sealants and gaskets. Some emphasis is placed on weather resistance of joints in the external envelope of buildings.
The code does not present guidance in the form of a catalogue of proven joint designs, because the extent to which a design is appropriate to a particular use depends on circumstances specific to the building, e.g. its exposure, desired performance, durability and costs. The code therefore draws attention to matters that need consideration, in order that solutions may be developed that are appropriate. The code does not cover:
a) rigidly connected joints (except type I joints, see 4.6.4.1);
b) joints within components normally made in a factory, such as those around opening lights in windows:
c) the load-bearing functions of structural joints; d) glazing (see BS 6262);
e) joints in service pipes and ducts and their connections to appliances;
f) methods of test for joints or for jointing products.
NOTE All figures in this standard showing detailed joint designs illustrate principles in a recognizable context and are not production drawings of proven and universally applicable joints.
2 References
2.1 Normative references
BS 6093 incorporates, by reference, provisions from specific editions of other publications. These normative references are cited at the appropriate points in the text and the publications are listed on page 40. Subsequent amendments to, or revisions of, any of these publications apply to BS 6093 only when incorporated in it by updating or revision.
2.2 Informative references
BS 6093 refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on page 40, but reference should be made to the latest editions.
3 Definitions
For the purposes of BS 6093:1993 pdf free download, the definitions given in BS 6100-1.3.6:1991, BS 6100-1.5.1:1984 and BS 6100-1.5.2:1987 apply, together with the following.
3.1 Joint design
3.1.1
induced deviation
dimensional deviation caused by work done NOTE The operations of setting out, manufacture, assembly and erection give rise to this type of deviation.
3.1.2
inherent deviation
dimensional deviation caused by an inherent material property
NOTE Changes in temperature, humidity, stress etc. give rise to this type of deviation.
3.1.3
interchangeability
ability of a component to be used and jointed satisfactorily with a variety of other components
3.1.4
joint (i)’
construction formed by the adjacent parts of two or more products, components or assemblies when these are put together, fixed or united with or without the use of a jointing product
3.1.5
joint (2)’
position in the construction works where the joint (1) is situated
3.1.6
joint clearance2
distance between the joint faces of adjacent building components, i.e. the joint gap widths considered in order to achieve fit
3.1.7
joint gap2
space between adjacent components, with or without a jointing product
4.5.4 Fixing of components
The functions of joints in the context of the fixing of components are to support joined components in one or more directions, to resist differential deformation of joined components, and to permit operation of movable components.
4.5.5 Appearance
Joints should have an acceptable appearance. The effects of weathering of the appearance (colour) of the jointing material itself should be borne in mind during its selection.
Joints should also avoid:
a) promotion of mould and plant growth;
b) discoloration due to UV radiation and biological, physical or chemical action:
c) all or part of the internal structure showing:
d) dust collection.
4.5.6 Durability
If a joint is likely to be less durable than the components joined, then the consequences and ease of repair should be considered. In considering durability and the minimum life of a joint, designers should aim to reduce its exposure, minimize damage to the fabric and, should the joint fail, provide access for repair or replacement, and establish the expected frequency of replacement (see also 8.6).
Joints may be required to resist abrasive action and damage or unauthorized dismantling. They may also be required to resist the action of animals and insects, plants and micro-organisms, water and water vapour and aqueous solutions or suspensions, polluted air, light and radiation, freezing of water, extremes of temperatures, airborne or structure borne vibrations, shock waves and high intensity sound, and acids, alkalis, oils, fats and solvents.
4.5.7 Maintenance (see also 8.6) The design of joints should allow for inspection. partial or complete dismantling and reassembly, and the replacement of decayed jointing products, during maintenance.
4.5.8 Ambient conditions Joints should be able to perform the required functions over a specified range of temperature, atmospheric humidity, air or liquid pressure differential joint clearance variation, and driving rain volume.
4.5.9 Functions that apply to a specific position A joint in a specific position may have particular requirements that need to be identified and specified accordingly.
Joint clearances should be considered to be “critical dimensions” and treated as required by clause 20 of BS 1192-1:1984, thus they should be shown on drawings as a target size with permitted deviations. This is illustrated in Figure B.1 as 8 * 2 mm . If this is felt to be unduly laborious the permitted deviations can be shown in the drawing notes. Indicating joint clearances in this way makes readily available the criteria for checking compliance on site and confirming that the joint can be expected to be able to accommodate future dimensional deviations in the way intended by the designer.
5 Materials for jointing
5.1 General
A classification of sealants, sealing strips, gaskets and baffles is given in Table 1. Table 2 gives a list and properties of various joint fillers.
Guidance on the selection, applications and use of sealants is given in BS 6213. More information is available on sealants than on gaskets which are normally purpose-made (for which only general guidance can be given). In all cases, the details of the properties and performance of seals should be obtained from the manufacturers.
There are at least two critical features of seal performance that have to be considered, firstly the interfaces between the seal and the components to be joined and secondly the nature of the sealing material itself.
5.2 Sealants
5.2.1 General
Sealants are classified as elastic, elastoplastic, plastoelastic or plastic according to their response to movement (Table 1).
5.2.2 Movement accommodation factor (MAF)
The MAF indicates the full range of movement between maximum compression and maximum extension that the sealant can accommodate. It is expressed as a percentage of the minimum design joint gap width in this code.
NOTE 1 MAF is sometimes expressed as a percentage about the mean joint gap width: this mode of expression is deprecated.
Low, medium and high movement accommodation factors correspond approximately to values of 5%, 15% and 25%.
NOTE 2 The MAF of some sealants reaches 50 %.