specification writting in architecture and civil
- 2. SPECIFICATION AND SPECIFICATION WRITING • Necessity of specification, importance of specification. How to write specification. • Types of Specification. Principles of Specification writing. • Important aspects of the design of specification, Sources of information. • Brief Specification for1st class, 2nd class, 3rd class building. • Detailed specification for earthwork excavation, plain cement concrete, reinforced concrete, first class and second class brickwork, damp proof course, ceramic tiles/marble flooring and dado, woodwork for doors, windows frames and shutters, cement plastering, painting & weathering course in terrace.
- 3. SPECIFICATIONS • The ideas of engineer are converted into reality –tool ---specification. • The term derived from French word- specifier-describe. • An engineering specification contains detailed description of all workmanship and materials which are required to complete a project in accordance with its drawing and details. • Many a time it is not possible to furnish the information on the drawings, regarding the quality of materials to be used and the quality of workmanship to be achieved during construction.
- 4. • This data regarding the materials and workmanship is conveyed in a separate contract document which is known as the ‘SPECIFICATION’ for the work. • Thus the drawing with the specification “will completely define the structure.” The “specification is furnished separately along with the drawing and is an essential part of all engineering contracts. • It deals with the nature, quality and class of work, materials to be used in the various parts of work ,their proportions, method of preparation, workmanship and description of execution of work are required for a construction.
- 5. Objectives and principles of Specifications • Specifications should describe the type and quality of every product, workmanship necessary required for the project. • The specifications should describe the requirements for fabrication, erection, application and finishing. • Specifications should include necessary codes and standards applicable to the project. • The engineer aims to protect the owner from any damage due to bad workmanship or low quality materials.
- 6. The cost of an unit quantity of work is governed by its specification. Specification is an essential contract document and is required for arbitration or court cases. Specification is necessary to specify the equipment, tools and plants to be engaged for a work and thus enable to procure them beforehand. The necessity of specification is to verify and check the strength of materials for a work involved in a project. A work is carried out according to its specification and the contractor is paid for the same, any change in specification changes the tendered rate.
- 7. PURPOSE OF SPECIFICATION • Specifies the workmanship and the method of doing the work. • It's serves as a guide to a supervising staff of a contractor as well as to the owner to execute the work to their satisfaction. • As the rate of work is based on the specification, a contractor can calculate the rates of materials and labour.
- 8. • Tender rate without specification of works is baseless, incomplete and invalid. • To verify and check the strength of materials for a work involved in a project.
- 9. Importance of specification • Drawings (dimensions, types of construction etc) • The instructions expressed well in words are written. • Provisions or documents made more legal strength incase of disputes.
- 10. How to write specification? • Description of materials: – The quality an size of materials required to do an item of work shall be fully described for checking up at site according to the buildings provided in the specification. • Workmanship: – Complete description of workmanship, the method of making of laying, preparation of base or surface, compaction, finishing and curing etc. specifically applicable to the item of work shall be clearly stated in different clauses.
- 11. How to write specification? • Tools and plants: – It against damage or the method of curing if required, the test of completed work if necessary shall be described in separate clause. • Expression: – While writing the specification endeavor shall be made to express the requirements of the specification clearly and in concise from avoiding repetition and unusual works.
- 12. Specification Language • Specification language should be precise. • Four important sections for specification writing 1. Be Clear 2. Be Correct 3. Be Complete 4. Be Concise(brief)
- 13. 1. Be Clear: 1. Use proper grammar. 2. Choose precise words to convey the message. 2. Be Correct: 1. Present information accurately. 2. Precisely using proper terminology. 3. Be Complete: 1. Do not out important or necessary information. 2. Brevity(shortness) at the expense of completeness should be avoided. 4. Be Concise: Eliminate unnecessary words.
- 14. Uses • Best guide to the contractor and his sub-contractors, material suppliers and architects or owner’s site supervisors. • Serves as a legal document.
- 15. Brief Specifications: • Quantity surveyor writes the brief description of every item. • They do not form part of the contract document. • Useful to the person preparing it. Detailed Specifications: These gives the detailed description of the various items of work laying down the Quantities and qualities of materials, their proportions, the method of preparation workmanship and execution of work. Types of specifications
- 16. Types of Detailed Specifications • The four methods are: – Descriptive – Performance – Reference Standard – Proprietary
- 17. 1-Descriptive Specifications • Specifying the exact properties of the materials and methods of installation are described in detail without using proprietary or manufacturer's names. • Brand names is restricted, and in situations where the Architect/Engineer want to exercise tight control over the specified work.
- 18. • for preparing descriptive specifications: 1. Research the important features required for the product. 2. Determine which features to describe in the specification and which features to show in the drawings. 3. Specifying the quality assurance measures (i.e, certifications, testing or inspection activities)
- 19. 2-Performance Specifications • Under this method the required end results are specified along with the criteria by which the performance will be judged and the method by which it can be verified. • The contractor is free to choose the materials and methods. • This gives the Contractor flexibility in selecting and applying products. • They are generally used to encourage the use of new and innovative techniques that may lead to more economical construction.
- 20. 3-Reference Standard Specifications – Under this method reference is made to an established standard defined by associations about a certain part or phase of construction. – They are used for "commodity" products in the marketplace, where brand names are not important. – The standard must be recognized as authoritative by the industry. Eg: – ASTM C170-90(1999) Standard Test Method for Compressive Strength of Dimension Stone.
- 21. 4-Proprietary Specifications – Under this method the actual brand names, model numbers and other proprietary information is specified. – They are primarily used for private commercial projects where the Owner knows what products they want. – There are two types of proprietary specifications --closed and open.
- 22. Eg: 1. Excavate foundation trenches. 200 m3 2. 200 mm concrete block walls in cm (1:4). 1625m2 3. 2 coats of emulsion paint on plastered walls. 2489 m2
- 23. Specification for excavation • Starting of work--workmanship—excavated material—protection to the existing services—measurement—what the rate includes.
- 24. • The excavation for the foundation trenches shall be carried out in all sorts of soils as per the plan. • The sides of the foundation trenches shall be vertical and bottom shall be uniformly levelled.
- 25. • The excavated materials shall be stacked away from the sides of the trenches by at least 2m. • The excavated material shall be filled in the plinth in layers of 30cm and well watered. • The surplus excavated material shall be spread out uniformly up to a lead of 100m.
- 26. • All the existing services such as water pipes, electric cables which are met within foundation trenches shall be carefully supported and protected by the contractor. • The measurement shall be done as per exact length and width of the lowest step of footings as per drawings. • The rate includes all timbering and other supports. • The materials or valuables found during excauvation shall be the property of the owner.
- 27. Specification for removal of water from foundation • Pumps—sumps—safety of adjoining structures.
- 28. Specification for damp proof course • Proportion—coarse aggregate—fine aggregate—cement— water proofing compound—mixing —preparation of base—laying—curin g.
- 31. Specification for brickbat cement concrete for foundation in proportion (1:2:4) • Proportion—cement mortar—brick bats—mixing—placing—ramming—measure ment.
- 32. Specification for brickwork I class in cm(1:6) • Properties of bricks—soaking in water—mortar—workmanship—measurement--sc affolding.
- 33. Bricks
- 34. • For class I Brickwork, all bricks shall be of first class of standard specifications made of good brick earth. • Bricks shall be thoroughly burnt, and shall be deep cherry red or copper color. • Bricks shall be regular in shape and their edges should be sharp. • Bricks shall emit clear ringing sound on being struck. • Bricks shall be free from cracks, chips, flaws and lumps of any kind. • Bricks shall not absorb water more than one-sixth of their weight after one hour of soaking by immersing in water. • Bricks shall have minimum crushing strength of 105 Kg per Sq. cm. (1500 lbs per sq. in.) • For class II Brickwork, bricks shall be of second class. • For class III Brickwork, bricks shall be of third class if otherwise not specified.
- 35. Cement Mortar • For cement mortar, cement shall be fresh portland cement of standard specifications. • Sand shall be sharp, clean and free from organic and foreign matters. • For rich mortar, coarse or medium sand should be used. • For weak mortar, local fine sand may be used. • Proportion of cement sand mortar may be of 1:3 to 1:6 as specified.
- 36. • Materials of mortar shall be measured to have the required proportion with measuring box. • Materials shall be first mixed dry to have a uniform colour in a clean masonry platform. • Then mix mortar by adding clean water slowly and gradually to have workable consistency and mixed thoroughly by turning at least three times. • Only freshly mixed mortar shall be used. • Old and stale mortar shall not be used. • Mortar for one hour’s work only shall be mixed with water so that the mortar may be used before setting starts.
- 37. Lime Surkhi Mortar • Generally can be used for class II and II Brickwork. • Lime surkhi (or sand or cinder) mortar if specified shall be mixed in the specified proportion by grinding in mortar mill for at least three hours on the same day of use. • Lime shall be fresh and slaked and screened at the site of work. • Fresh mixed mortar shall be used within 24 hours. • Old and stale mortar shall not be used. • For small work, hand mixing may be allowed in the same manner as for cement mortar described above. • Proportion of lime surkhi (or sand or cinder) mortar may be 1:2 to 1:3 as specified.
- 38. Soaking of bricks • For class I Brickwork, bricks shall be fully soaked in clean water by submerging in a tank for a period of 12 hours immediately before use. • For class II Brickwork, , bricks shall be fully soaked in clean water by submerging in a tank for a period of 3 hours immediately before use. • For class III Brickwork, bricks shall be dipped in tub of water before use. • Soaking shall be continued till air bubbling is ceased.
- 39. Bricklaying • Bricks shall be well bonded and laid in English bond unless otherwise specified. • Every course shall be truly horizontal and wall shall be truly in plumb. • Vertical joints of consecutive course shall not come directly over one another. • Vertical joints in alternate course shall come directly over one another. • No damaged or broken bricks shall be used. • Closers shall be of clean cut bricks and shall be placed near the ends of wall but not at the other edge. • Selected best shaped bricks shall be used for face work. • For class I Brickwork, mortar joints shall not exceed 6 mm (1/4″) in thickness.
- 40. • For class II Brickwork, mortar joints shall not exceed 10 mm (3/8″) in thickness. • For class II Brickwork, mortar joints shall not exceed 12 mm (1/2″) in thickness. • Brickwork joints shall be fully filled with mortar. • Bricks shall be laid with frogs upward except in top course where frogs shall be placed downward. • Brickwork shall be carried out not more than 1 m (3 ft) in height at a time. • When one part of the wall has to be delayed, stepping shall be left at an angle of 45 degree. • Corbelling or projections where made should not be more than 1/4 brick projections in one course. • All joints shall be raked and faces of wall cleaned a the ed of each day’s work.
- 41. Curing • The brick work shall be kept wet for a period of at least 10 days after laying. • At the end of day’s work, tops of wall shall be flooded with water my making small weak mortar edging to contain at least 25 mm (1 “) deep water.
- 42. Protection • The brickwork shall be protected from the effect of sun, rain, frost etc. during the constructions and up until such time it is green and likely to be damaged.
- 43. Scaffolding
- 44. • Necessary and suitable scaffolding shall be provided to facilitate the construction of brick wall. • Scaffolding shall be sound and strong. • Supports and members of scaffolding shall be strong so as to withstand all loads likely to come upon them.
- 45. Measurement • Brickwork shall be measured in cu m (cu ft). • Different kinds of brickwork with different mortar shall be taken under separate items. • The thickness of wall shall be taken as multiple of half brick as half brick 10 cm, 1 brick 10 cm, 1-1/2 brick 30 cm and so on. • The rate shall be for the complete work including scaffolding and all tools and plants.
- 47. • In addition of the above, for brickwork in arch, type of arch – rough arch or axed or gauged arch as the case may be, and the centering of the arch should be specified.
- 48. Specification for timber doors and windows • Properties of timber—fabrication and fixing—fixing of shutters—design of shutters—frames—workmanship—fastening and fixtures—oil paint—measurement.
- 49. Specification for random rubble masonry • Properties of stones—mortar—workmanship—curing—meas urement—scaffolding.
- 50. Specification for coursed rubble masonry • Properties of stones—mortar—workmanship—curing—meas urement—scaffolding.
- 51. Specification for R.C.C. work proportion (1:2:4) • Proportion—cement—fine aggregate—water—reinforcement—centering— mixing—laying and curing—finishing of exposed surfaces.
- 52. • The proportion of cement shall be one part of cement, two parts of sand and four parts of aggregates by volume. • The cement to be used shall comply with the standard requirements. • The sand to be used shall be clean and coarse and free from organic or vegetable matters. • The coarse aggregate shall consist of 67% of black trap metal or kapachi of sizes 20mm to 40mm and 33% of black trap metal or grit of sizes 20mm to 6mm. • The water used to be clean and fresh.
- 53. Specification for terrazzo finish • Marble chips—first coat—second coat—process of polishing--measurement.
- 54. Specification for marble finish • Quality of Marble—samples—anchors and dowels—vertical and horizontal surfaces—workmanship--finishing--measureme nt.
- 55. Specification for cement concrete flooring in proportion(1:2:4) • Cement—fine aggregate—coarse aggregate—water—subgrade—proportion and mixing—laying—shuttering—casting--finishin g—curing--measurement.