The following standard abbreviations are recommended but, if there is any risk of confusion or ambiguity with the then use of the these words abbreviations in any particular circumstances should be written in full. No other abbreviations should be used unless clearly defined on all the drawings on which they appear. articular attention is drawn to the use of lower-case and capital letters.All abbreviations are the same in the plural in the singular.
RC – reinforced concrete
blk – blockwork
brk – brickwork
drg – drawing
FS – full size
NTS – not to scale
dia – diameter
crs – centres
SOP – setting-out point
SOL – setting-out line
CL – centre-line
FFL – finished floor level
SFL – structural floor level
SSL – structural slab level
EL – existing level
hor – horizontal
ver – vertical
RC Detailing – Reinforcement Concrete Detailing
2.4.2 Relating to reinforcement
far (face) Fl (outer layer) F2 (second layer)
near (face) N1 (outer layer) N2 (second layer)
bottom (face) B1 (outer layer) B2 (second layer)
top (face) T1 (outer layer) T2 (second layer)
Note: Since the contractor may not be familiar with this notation it should be illustrated by a sketch on the relevant drawings. Additional abbreviations may be used but are not recommended for use without a clear description as they have been found to be ambiguous.
2.5 Drawing standards
It is the intention that BS 1192 Recommendations for drawing practice should be read in conjunction with this document, the two documents being mutually complementary. Parts 1and 3 of BS 1192 are particularly relevant to the RC Detailing since the reinforced concrete detailer define the general principles of drawing practice and symbols. In Part 2 of BS 1192 are examples or ranforced concrete drawings, which also comply with the Standard method.
2.6 Dimensions of drawing sheets
The recommended dimensions of drawing sheets are given below; Fig. 1 shows the relative sizes. Size of drawing sheets BS reference dimensions
A0 841 × 1189
A1 594 × 841
A2 420 × 594
A3 297 × 420
A4 210 × 297
Note: Margins and information panels are within these dimensions
All drawings should have a 20mm filing border on the left-hand side. Elsewhere the border should be 20mm (minimum) for A0 and Al and 10mm (minimum) for A2 A3 and A4. The border margin line should be at least 0.5mm thick.
2.8 Title and information panels
Key information relating to the job and drawings should be placed in the bottom right-hand corner of the drawing sheet. Panel should include at least the following information:
office project number
drawing number with provision for revision suffix
office of origin
drawn by (name)
checked by (name)
date of drawing.
On jobs where a portion of the work has to be divided into several drawings, it is useful to have a small diagrammatic key on each drawing, with the portion covered by that drawing clearly defined, and adjacent panels identified with given drawing number.
2.10.1 Site plans
The direction of the north point should be clearly shown.
2.10.2 All other drawings
All other drawings relating to particular buildings or major subdivision of a job should have consistent orientation, which should preferably be as close as possible to the site-plan orientation.
2.11 Thickness of lines
The objective of using varying line thicknesses is to improve clarity by differentiation. The scale of drawing and the need for clear prints to be taken from the original should be borne in mind The following suggested line thicknesses are considered suitable for reinforced concrete drawings:
concrete outlines generally and general
arrangement drawings 0.35mm
concrete outlines on reinforcement
main reinforcing bar 0.7mm
dimension lines and centre-lines 0.25mm
Cross-sections of reinforcement should be drawn approximately to scale.
Distinct and uniform letters and figures ensure the production of good, legible prints; the style should be simple.
Capital letters should be used for all titles and sub-titles and should preferably be mechanically produced. Lower-case letters may be used in notes.
The spelling of all words should be in accordance with BS 2787 or otherwise the Little Oxford Dictionary, e.g. asphalt, kerb, lintel, etc.
The general-arrangement drawing should show all setting out dimensions and sizes of members. The reinforcement drawings should contain only those dimensions that are necessary for the correct location of the reinforcement. Dimensions should be written in such a way that they may be read when viewed from the bottom or the right-hand Side of drawing. They should, where possible, be kept clear of structural detail and placed near to and above the line, not through the line .For site layouts and levels, the recommended unit is the metre. For reinforcement detailing and the specification of small sections, the recommended unit is the millimetre It is not necessary to write mm. Dimensions should normally be to the nearest whole millimetre.
On civil-engineering and major building works it is usually necessary to relate the job datum(a TBM or transferred OS benchmark) to the Ordnance Survey datum. On other works, a suitable fixed point should be taken as job datum such that all other levels are positive. This datum should be clearly indicated or described on the drawings, and all levels and vertical dimensions should be related to it. Levels should be expressed in metres.
2.15.2 Levels on plan
Lt is important to differentiate on site layout drawings between existing levels and intended levels.
Finished floor levels or structural floor levels should be indicated thus:
Existing levels should be indicated thus:
2.15.3 Levels on section and elevation
The same method should be used as for levels on plan. except that the level should be projected beyond the drawing with a closed arrowhead indicating the appropriate line.
When constructing a structure it is the level of the structure that is important. If it is necessary to refer to the finished floor level, this should be a reference in addition to the structural floor level
Scales should be expressed as, for example, 1:10 (one to ten for concrete work). The following scales are recommended as a suitable:
1:100 general arrangements
1:50 wall and slab detail
1:50 beam and column elevations
1:20 beam and column sections
Where larger scales are required the preferred scales specified in BS 1192, are: 1:20, 1:10, 1:5,1:2 or full size.
Plans should be drawn in such a way as to illustrate the method of support below, which should be shown as broken lines, This is achieved if one assumes section drawn a horizontal immediately above the surface of the structural arrangement or component. Dimension lines should be kept clear of the structural details and information.
An elevation on a portion of a structure will normally be taken as a vertical cut immediately adjacent to the element under consideration. Structural members cut by the section should be shown in full lines. Other connecting members behind the member being detailed should be shown by broken lines.
Where sections are taken through structural elements, only the material in the cutting plane is shown on a section; in general a cut showing features beyond should not be used.
For clarity, the cut member may be shaded. The directions of sections should be taken looking consistently in the same direction, looking towards the left for beams and down wards for columns. A section should be drawn as near as possible to the detail to which it relates.
2.20 Grid lines and a recommended reference system
A grid system provides a convenient datum for locating and referencing members, since columns are usually placed at or near the intersection of grid lines.
Grid notation should be agreed with the architect and would normally be numbered 1.2,3, etc. in one direction, and lettered A, B, C, X, Y, Z, AA, AB, etc. (omitting I and O) in the other direction. These sequences should start at the lower left corner of the grid system. Supplementary grids, if required, can be incorporated within the system and identified as follows: Aa, Ab, Ac, Ba, 2.5,4.2 etc.
Referring to the framing plan sketch: all beams within a floor panel are referenced from the column situated in the lower left corner of that panel, e.g. column reference 2B occurs at intersection of grids 2 and B
each beam reference includes the column reference plus a suffix number, e.g. 2B1, 2B3,etc. for beams spanning up the panel, and 2B2, 2B4, etc. for beams across the panel. Similarly for supplementary column 2.5 Ba. This format is similar to the system used successfully for structural steelwork. Beams should be labelled on the general arrangement drawing, particularly off-grid members. Beams on grid lines may have their labels omitted, in which case strings of beams are described as follows: e.g. beams along grid line 2/A to C
2.21 Procedure for checking drawings and schedules
All drawings and bar and fabric schedules must be checked by a competent person other than the detailer. The checking of drawings falls into 3 stages:
Stage 1: Design check
That the drawing correctly interprets the design as described as described in and supported by the checked calculations.
Stage 2: Detailing check
That the drawing has been prepared in accordance with current standards and meets the requirements of that particular job. That the information agrees with the general arrangement and other associated drawings and bar and fabric schedules, with particular reference todimensions, termination of reinforcement, construction details, notes, etc., and that the details shown can, in practice, be constructed. Where drawings are traced they must be checked to ensure they have been traced correctly, and where the layout of the drawing has been rearranged on the tracing. that the traced drawing continues to convey the intentions of the originator to the user.
Stage 3: Overall check
That the checks under stages 1and 2 have been carried out. That the drawing is in all respects suitable for its purpose and truly reflects the requirements of the project.
Each drawing should have a ‘box’ containing the name of the draughtsman and checker.
Standard checking lists may be a useful aid but must not be considered a complete check, since no checklist can be totally comprehensive. Set out below are some items that could be used to form the basis for a checklist.
1. Is general presentation and orientation correct?
2. Are title, scales, drawing numbers correct?
3. Are revision letters correct and location of revisions shown?
4. Are sufficient sections and details given?
5. Are general notes complete and can they be understood?
6. Is spelling correct?