Specification & Quantities Estimating Lecturer Maha Muhaisen College of Applied Engineering& Urban...

Specification & Quantities Estimating

Lecturer

Maha MuhaisenMaha Muhaisen

College of Applied Engineering& Urban Planning

Course Aims & Objectives

At the completion of this course, the student will:

Recognize the preliminary and detailed estimating methods and focusing on the elements for construction projects

To be familiar with cost analysis and preparation for bidding.

Understanding and be familiar with the construction specification in particular for building.

Course Outline

Part 1 : Quantity SurveyIntroduction to Engineering project including

project cycle, & bidding documents.Quantities surveying and calculation of

different areas.Methods of measurement of the works.Pricing & cost analysis.Payment certificate.Application on Engineering project

Part 2 : Technical specification

Earth worksConcrete worksMasonry worksPlasteringTilingMetal workCarpentry workPainting worksGlazingPlumbing worksElectrical works

The Engineering ProjectThe Engineering Project

ProjectProject

Structural Structural worksworks

Architectural Architectural WorksWorks

Electrical Electrical WorksWorks

Mechanical Mechanical WorksWorks

Types of construction Engineering Types of construction Engineering Projects :Projects :

- Building construction- Roads Construction- Water Systems- Sewerage and Storm water systems

Project Cycle

Studies, design, tendering

Implementation & supervision

Taking- over, and operation

Main stages in construction project1- Concept : identify the project needs, and objectives2- technical studies as feasibility study, possibility of

implementation, primary cost, and possibility of financing …..etc.

3- Preliminary design4- Detailed design including architectural , structural, electrical,

mechanical.5- Tender documents.6 – Tendering7- Contract Award8- contract agreement9- starting construction10- Preliminary handing over the project11- the operation of the project12- maintenance period13- Project final handing over.

Construction Project CycleP

erc

en

t C

om

ple

te

Stage I Stage II Stage III Stage IV

Project "GO" Decision

Major Contracts Let

Installation Substantially Complete

Full Operations

Feasability- P roject Formulation - Feasabiltiy Studies- Strategies Design & Approval

Planning & Design - Base Design - Cost & Schedule- Contract Terms & Conditions. - Detailed P lanning

Turnover & Start Up- Final Testing - Maintenance

Construction - Manufacturing - Delivery - Civil Work - Installation - Testing

Figure 1.1 : Construction Projects Life-Cycle (Ref: PMBK, 2000)

Tender DocumentsTender Documents

Invitation to bid Instruction to bidders Information to bidders & bid data Biding Forms General conditions of contract Specific condition of contract Specification BOQ Drawings Contract forms

The Project Parties

The Employer /OwnerThe consultant: who appointed by the

employer to do the design and bidding documents and supervise the construction work.

The contractor: who was approved by the employer to implement the works according to the submitted bid.

Other PartiesMunicipalities, ministries, suppliers, techniciansSubcontracts, workers,Insurance companiesBanks and other financing agencies.

Construction Project Teams

Main tasks for engineering teams in Main tasks for engineering teams in the project are :the project are :- design- Implementation / construction- supervision

Construction Project Teams

Quantity Surveyor

He the person who is responsible on estimating the quantities from the design drawings, and measurement of the quantities in the site during the project implementation, and preparing the current and final payments.

Quantity Surveys (take off)

It is the quantity of works/material take off , required for the completion of project implementation, and listed as items in table of quantities.

In general we can describe quantity survey In general we can describe quantity survey as follows:as follows:

1.Description and preparation of the bill of quantities and its items required for the tender.

2.Preparation of the site material, material types, and material distribution.

Quantity surveys (take off) .. Cont.Quantity surveys (take off) .. Cont.

Describe the items and preparing BOQPreparing of the cost estimate in BOQ.Preparation of the list of the site needs

(technician / workers)Preparation of the due payment statements

(contractor payments during the construction)

Tasks of the Quantity SurveyorTasks of the Quantity Surveyor

First : in the consultant office :Stage 1 :During the preparation of bidding

documents :- Preparation of the BOQ from the design drawing

which part of bidding documents.- Preparation of cost estimate for items listed in BOQ- Review and check the bids submitted from bidders.- Preparation of the lists of the contents of bids

received.- Sharing in evaluation and preparation of t

recommendation to award the contract to be submitted to owner.

Quantity Surveyor TasksQuantity Surveyor Tasks

22 Stage 2 :Stage 2 : During the supervision of the During the supervision of the constructionconstruction

- Review and checking the payments submitted from the contractor.

- Preparation of the reports about the conformity of the quantities items with contract documents.

Second : In the Contractor CompanySecond : In the Contractor Company

- During the implementation :- During the implementation :- Review and checking the BOQ at the starting of the

work.- Prepare the eng. Measurement for the quantities of

the finished works.- Prepare lists of the site needs (material, workers,

technicians)- Calculate the remuneration of the subcontractors,

workers, equipments,…etc.- Prepare the payment statements- Prepare the detailed reports describing the situation of

the items quantities, (plus or minus the contract BOQ)

Required SkillsRequired Skills

Ability to understand the drawings details, design drawings, shop drawings, as built ).

Excellent knowledge of the calculation of the areas and volumes, knowledge of fees of workers e /technicians/ , rules and law of the contracts,

In addition to the knowledge of related financial issues/ taxes, banks transactions, insurances and its implication.

Knowledge of the productivity of the workers and technicians.

Stages of the Quantity SurveyStages of the Quantity Survey

Stage1 : preparation of the engineering measurement and calculations of the works during the preparation of the bidding documents (consultant) and

- preparation of the measurement of the accomplished works in the site and prepare in the site and prepare the payment (contractor)the payment (contractor)

Stage 2 : preparing BOQStage 3 : review and check the financial

payments.

Areas, Volumes, & Surface areas

See attached PDF file

Next Lecture :Special calculations of the areas and volumes.Measurement of the works.

Method of measurements 1- Conventional measurement (1- Conventional measurement ( البلدي البلدي الكيل ((الكيلDepends on experience, and type of project.Doesn't govern by theories or engineering basics.Not considered as scientific method.Doesn't subtract the opening as windows or doors from the

block, plastering, painting works and computing whole wall.Another example : as the every 3 steps in stair = 1 m3

2- Engineering measurement (2- Engineering measurement ( الهندسي الهندسي الكيل ((الكيلIt is calculating all the works finished after subtracting all

opening.

Cont.unit measurement example

Lump-sum (L.S)

Works have details difficult to be

calculated

Earth work, earthling system (electrical),,

M.R Works have specific length and width

As pipes

No. Works have 3 dim. fixed

Windows, doors,

M2 Works with specific thickness,

as plastering, painting,

M3 Variable dimensions

Footings, columns, stairs,

Ton / kg Have specific width As steel

Day / hrs Labor / equipment Workers wages, equipment,

Types of construction works

Building constructionRoads construction Water Booster P.S and piping,Sewage and storm water P.S and piping.Electrical construction

Preparation of engineering measurements

measurement sheet project name _________________contractor name ____________engineer name _______________

length width heigth Total amountDimension

SN Description Unit Quantity Unit rate

Item unit Method of measurement

Site leveling Lump sum It takes into consideration all site leveling including the excavation, fill, till reach 0+B.M according to design drawing.

Excavation (cut) m3 Measured by 2 methods :1- footings areas according to blinding area * depth of excavation according to drawings.2- external dimensions of the building *depth of footings

Fill (backfill) m3 = excavation – concrete work for footings and columns under ground level. = ground plan *depth of ground beams – (concrete for ground beams and ground floors)

Measurement of works / Earth Work

Concrete works measures engineering measurement

All opening more than 0.1m2 or 0.1 m3 are deducted.

The concrete works more than the areas, volumes in the drawings doesn’t included.

Measurement of works / concrete works



Blinding concrete, ground concrete, benching, and slabs concrete with fixed thickness

m2 = length * width (the thickness should be specified in the drawings and specifications) Ribs blocks don’t subtract from the slabs concrete.

Footings, columns, ground beams, stairs, and canopies,

m3 = length*width*thickness-Ground beams are measured from its connection with columns- concrete stars include the stairs , steps, stair slabs, walls supporting the stairs.

Concrete decoration works as curves.

No. The dimensions must be specified in the drawings.

Measurement of works / block worksItem unit Method of measurement

Block works m2 = length * width (the thickness should be specified in the drawings and specifications) - subtracting all openings more than 0.1 cm2.

Measurement of works / Plastering/ painting works


Length * width M2 = length * width (engineering measurement after subtracting the openings, more than 0.1 m2) - the area is measured above the skirting (terrazzo chips)

Internal plastering = walls + slabs

Measurement of works / tilling works


Terrazzo, marble, ceramic

m2 = length * width (engineering measurement)



Plastering & painting

M2 = length * width (engineering measurement after subtracting the openings, more than 0.1 m2) - the area is measured above the skirting (terrazzo chips)

Internal plastering = walls + ceiling

Measurement of works / Doors


Doors No. The exact dimensions should be specified in the design drawings.Sometimes carpentry works measured in m2 or m length according to the item described in BOQ.

Measurement of works / Windows


windows No. The exact dimensions should be specified in the design drawings.Sometimes carpentry works measured in m2 or m length according to the item described in BOQ.

Measurement of works / electrical & sanitary works


Electrical and sanitary pieces / accessories

No. The dimensions should be specified clearly in the design drawings as the sockets, lamps, fluorescent lighting,…etc(W.C. , washing basins, sinks, manholes, pumps…etc)

piping M.R The dimension and details should be specified in the drawings, as (cables, pipes, ..etc)

Works with special detail

Lumps sum All details should be specified in the drawings, as earthing, gas network,

Bill of QuantitiesThe results in the quantities book, are recorded in the BOQ table.It is preferable to add 5-10% percentage on the quantities for

contingency to avoid any errors or any.

Preparation of engineering measurements

measurement sheet project name _________________contractor name ____________engineer name _______________

length width heigth Total amountDimension

SN Description Unit Quantity Unit rate


Site leveling Lump sum It takes into consideration all site leveling including the excavation, fill, till reach 0+B.M according to design drawing.

Excavation (cut) m3 Measured by 2 methods :1- footings areas according to blinding area * depth of excavation according to drawings.2- external dimensions of the building *depth of footings

Fill (backfill) m3 = excavation – concrete work for footings and columns under ground level. = ground plan *depth of ground beams – (concrete for ground beams and ground floors)

Measurement of works / Earth Work

Concrete works measures engineering measurement

All openinng more than 0.1m2 or 0.1 m3 are deducted.

The concrete works more than the areas, volumes in the drawings doesn’t included.


Measurement of works / concrete worksItem unit Method of measurement

Blinding concrete, ground concrete, benching, and slabs concrete with fixed thickness

m2 = length * width (the thickness should be specified in the drawings and specifications) Ribs blocks don’t subtract from the slabs concrete.

Footings, columns, ground beams, stairs, and canopies,

m3 = length*width*thickness-Ground beams are measured from its connection with columns- concrete stars include the stairs , steps, stair slabs, walls supporting the stairs.

Concrete decoration works as curves.

No. The dimensions must be specified in the drawings.

Measurement of works / block worksItem unit Method of measurement

Block works m2 = length * width (the thickness should be specified in the drawings and specifications) - subtracting all openings more than 0.1 cm2.



Length * width M2 = length * width (engineering measurement after subtracting the openings, more than 0.1 m2) - the area is measured above the skirting (terrazzo chips)

Internal plastering = walls + slabs

Measurement of works / tilling works


Terrazzo, marble, ceramic

m2 = length * width (engineering measurement)



Plastering & painting

M2 = length * width (engineering measurement after subtracting the openings, more than 0.1 m2) - the area is measured above the skirting (terrazzo chips)

Internal plastering = walls + ceiling

Measurement of works / Doors


Doors No. The exact dimensions should be specified in the design drawings.Sometimes carpentry works measured in m2 or m length according to the item described in BOQ.

Bill of Quantities The results in the quantities book, are recorded in

the BOQ table. It is preferable to add 5-10% percentage on the

quantities for contingency to avoid any errors or any.

No. Item description unit Quantity Unit price($ or NIS …)

Total amount($ or NIS …)

1 The works include…… L.S

Bill of Quantities

See the attached example

The items are classified into categories as shown in the next table.

at the end of BOQ, summary of the items are shown as well as the total amount of the price

Bill of Quantities

Summary tableNo. Item Total amount

($ or NIS …)

1- EXCAVATION & EARTH WORKS

2 CONCRETE WORKS

3- BLOCK WORK

4- CARPENTRY

5- METAL WORK

6- FINISHING WORKS

7- PLUMBING WORKS

8- ELECTRICAL WORKS

9- MISCELLANEOUS

Item description Based on drawings, specification. It should be accurate and reflect the

drawings and specifications, Description should include :

1- description of the works2- unit3- determine the method of measurement.

How to read the description Description of the items Drawings, details Specifications General and specific conditions Instruction of the supervisor engineer

the work price should include The description of the item should

include all the work that the unit price will take account of as will be illustrated in the following

1- Earth work The unit price should include :- Excavation in any kind of soil, rock, etc., starting at reduced

level (bottom of G.B. blinding) down to bottom of foundation blinding including compacting backfill around foundations and shall be applied on layers, 200 mm thick, watered and compacted to 95 % (98%) according to modified AASHTO Density Test T-80.for the excavated foundation and removal of surplus material from site to an approved dumping area complete as per specifications.

- Site Leveling. (Excavation of all Site including External Works). Cut and / or fill in any kind of soil, concrete, or asphalt; to the required Levels approved by the Engineer (Reduced Level). Including scraping of top. Any damage to the external walls, fence, etc. should be maintained without any compensations..

- Test of the soil (4 points at least)- Safety around the site,- Work according to engineer instruction and specifications

Concrete workConcrete works include: All formworks and shuttering in any form, shape and size.

Making chamfered and curved edges, allowing for and making grooves and sleeves and the like; removal of forms and cleaning of all exposed tie wires and rods; making good the harmed surfaces and

Supplying, Casting, vibrating and curing as per specifications. Approved additives and admixtures. Incurred costs on Concrete Mix Designs, Sample taking,

testing and providing test results certificates, storing and saving of samples, and preparation of bar bending schedules and workshops.

Supplying reinforcement of any grade, size and length as detailed in the drawings, storing on site including cutting, bending and fixing in position and providing all tying wires, spacers, shop drawings, testing and bar bending schedules

Concrete work (cont’d) Painting of exposed surfaces of underground

reinforced concrete elements with two coats of Bituminous Emulsion. Supply of Polyethylene sheets under ground slabs.

Steel bars used for alignment and fixing of reinforcement works, and extra steel added to assure proper detailing and safety.

Measurement of Concrete elements shall be the net dimensions as detailed in the drawings. All recesses, openings and voids shall be deducted.

Measurement shall be only for the seen surfaces of elements, overlapping and measuring items twice under separate headings shall not be allowed.

Supplying and fixing of the required steel reinforcement as per drawings and specifications.

Block worksRates of Block works include All works of the bill shall be of Concrete blocks of high

quality standards and as per specifications. Vertical and horizontal joints., Cement and mortar,

Galvanized angles and ties., Closed end blocks at all ends, door and window jambs, reveals and the like.

Concrete filling including reinforcing steel to cavities at quoins and door and window openings.

Lintels and bond beams to the full length of the wall, and all needed to complete job as per drawings and

specifications concrete infill and transporting, placing compacting,

curing, surface finishing, protection, construction and expansion joints and all labors and materials and tests.

Block works (cont’d)

Block work shall be bonded to concrete columns, wall and the like with concrete infill B250. block must be stopped in graded shape (10-15 cm from the concrete face) one 8 mm bar must cast in columns during casting with 40 cm length fixed every 42 cm horizontally, in addition to two vertical 10 mm bars.

Plastering works, includes The price shall include, all narrow widths, for taking out

joints on block walls or backing concrete face for key, for making good to frames around pipes and other fittings , plastering to jambs and reveals of openings ( النافذة من جانب

للجدار الخارجى السطح وبين اطارها side of columns, window ,(بينsills; all of which shall be included Price shall also include Expanded metal lath, angle beads at all corners and plaster stops at opening edges, expansion joints, sills, labor, curing, erecting and dismantling of scaffoldings سقاالت), additives, pigments and all incidentals required as specified

Material, workmanship, Galvanized mesh, or plastic mesh, False ceiling from galvanized mesh and plastering (fixing mesh , covering it by 3-coats of rough plaster) reinforcement of the joints between different material as

the joints between the wall and columns.

Tilling works Rate shall include preparation of surfaces under tiles, special tile

peace’s for edges and the like, tile surface finishing, Plastic spacers. Pointing and cleaning and all incidental as per specifications.

Supply, Install and Terrazzo Tiles, include, bedding and jointing in cement and sand mortar, pointing with white cement, required sand fill, and polishing, workmanship, and all incidental as per specifications

Isolation works for kitchen and bathroom (layer of fiber glass, and bitumen layers)

Marble includes connections, joints, mortar, and any other needed work. Supply and install a layer of cement and sand under marble and

porcelain , ceramic, according to specification and engineer instruction. Supply and spread a layer of sand under the tiles. Any decoration works as drawings

Painting works All Paints shall be supplied to site in sealed

container, as approved by the Engineer, and site mixing shall not be permitted.

The Contractor rates shall include for supply of all materials, workmanship, samples, surface preparation , protection of painted surfaces , application to all heights as required of works, repair of all damaged surface, as per specification.

CARPENTRY AND JOINERY WORKS (window & doors) Sizes of carpentry works given in the Bills of Quantities are finished sizes

and shall be as per Drawings. Sizes of doors and other items mentioned in the Bills of Quantities shall

allow for tolerance to suit the structural openings shown in the Drawings. Wooden doors and pair of doors shall be measured in square meter for

each structural opening, unless stated otherwise in the Bills of Quantities. Rates for carpentry and joinery work shall include : Shop and coordinated drawings. frames, architrave (عارضة ), and other holders Allowance for plastering and tiling and the like. Cutting and fitting around obstructions, Bedding and painting. Grounds, blocking and backings. Plugging concrete, block work, and stone work , and making good. Ironmongery including cylindrical locks, handles, stoppers, screws,

temporary fixing, re-fixing, oiling and adjusting.

STEEL AND ALUMINUM WORKS

Rates for metalwork shall include for : Preparing shop drawings, Drilling, counter sinking, screwing, bolting and riveting. Sub frames, including galvanized steel frames for Aluminum

windows and architrave. Gaskets, sashes, double weather strips and external and internal

approved quality silicon filling around frames. Ironmonger including cylindrical locks (Union or equal) , stoppers,

handles, temporarily fixing, refitting, oiling and adjusting. Providing two keys for each lock . Glass and glazing including cutting to size, putty and rubber. Preparing surfaces for and painting one coat of primer before

fixing. Sealing and Painting to any area or width in any location including

work in multicolor and cutting in edges. All other accessories and incidentals required to execute the work.

Electrical works All items price to include Supply, Installing, Connecting and

testing unless otherwise indicated, the contractor are requested to have approved full coordinated work shop drawings before starting contract activities, the price also includes all works necessary to implement electrical works in approved manner.

The contractor intended to order main and final distribution panel boards according to approved manufacturer drawings.

The price to include submittals, catalogs, any manufacturer instruction .

The contractor should install and construct all works according to drawings , specification tender documents, and requirement of Electrical Co.

Contractor should also test & submit the electrical Work to the Electricity Co. & Municipality.

PLUMBING, SANITARY AND MECHANICAL WORKS

Rates shall include all fittings , fixtures , appliances and pipe laying Supply of material, workmanship, installation, testing and commissioning.

Rates to include also all peaces and fittings, including by passes , floats, cleaning outlets , automatic vents, vents and stack covers, valves and non return valves and the like needed to complete works as per specifications.

Insulation and painting as called for in specifications. Excavation and cutting for all pipe laying works, bedding

back filling and all works connected with pipe laying. All ties, sleeves, joints, tie bolts and rods, brackets and

the like. Rates to include Workshops, Coordinated and as- built

drawings as approved by the Engineer

Pricing & price analysis Before construction three types of pricing :

1- cost estimate2- pricing3- cost analysis

Factors affecting the pricing

Raw material Workmanship, labor, sub-contractors Administration cost including direct cost as salaries,

equipments, transportation ..etc. and indirect cost as electricity, communication cost, banks , municipality fees, ,,,etc.

Unforeseen expenses & risk (3-5%) Insurances Taxes as income tax, V.A.T, Profit (7-10%)

Productivity of labor

It is necessary to calculate the productivity for the work teams either worker or technicians / equipments to calculate wages, for workers / subcontractors.

Productivity is measured per hour or per day.

Pricing analysis stages :Estimate the price for raw material and

workmanship.Estimate the percentage of the specified

work from the total project work . (work item/total work *100%)

Estimate the cost of administration / management , tax, insurances, risk, and profit.

Estimate the total cost for all works item.Estimate the unit price for each item.

Example:Analyze the prices, and find the unit price for

the following, knowing that, 1- Administrative expenses is fixed (1000$) for

project2- Unfixed expenses / indirect (400$)3- Insurance 200 $

ID Description of work unit quantity

1 Concrete footings M3 78

2 Block works for wall (20*20*24cm) M2 100

3 Internal plastering M2 200

4 Wooden door 90*220 No. 10

1- Price for raw material and workmanship- Concrete footing (B250)

ID Description Raw material per m3

price workmanship

1- Concrete footings (B250) Concrete 190 100Steel 170Wires 5

Nails, bolts 2

Water 1isolation 3

total 371 100Total price (NIS) 471Total price ($) 134$

Total for 78 m3 134*78 = 10,960 $


price workmanship

Block 20*20*40 block 12.5*2=25 6

Morter 3

Moving the blocks

2

Joints, concrete fill

5

total 35 6

Total price (NIS) 41

Total price ($) 11.7

Total for 78 m3 11.7*100= 1170$

Block work (20*20*40 cm)

Internal plastering


price workmanship

Internal plastering scaffolding o.5 6

Morter 4

Angles, metal grid, ..etc

0.5

water 0.5

total 6 6


Total price ($) 3.4

Total for 200 m2 3.4*200= 680$

Wooden doors 220*90 cm


price workmanship

Wooden door 220*90 material 400 50

Misce. 20

total 420 50


Total price ($) 135

Total for 10 doors 135*10 =1350$

percentage of the specified work from the total project work

ID Description Total work price % from total work

1 Concrete footings (B250) 10960 77.40%

2 Internal plastering 680 4.80%

3 Wooden door 220*90 1350 9.53%

4 Block 20*20*40 1170 8.26%

5 Total 14160 100.00%

2- the cost of administration / management , tax, insurances, risk, and profit.

administration expenses

ID Description fixed (1000$)

variable (400$)

tax (10%)

Insurance

(200$)

risks (5%)

profit (10%)

Total

1 Concrete footings (B250)

774.01 309.6 1096 154.8 548 1096 3978.4

2 Internal plastering

48.02 19.21 68 9.61 34 68 246.8362

3 Wooden door 220*90

95.34 38.14 135 19.07 67.5 135 490.04

4 Block 20*20*40 82.63 33.05 117 16.53 58.5 117 424.70

total cost for all works itemID Description stage (1) stage (2) total

1.00 Concrete footings (B250)

10,960.00 3,978.42 14,938.42

2.00 Internal plastering 680.00 246.84 926.84

3.00 Wooden door 220*90 1,350.00 490.04 1,840.04

4.00 Block 20*20*40 1,170.00 424.70 1,594.70

unit price for each itemID Description unit quantity unit price total

1.00 Concrete footings (B250)

m3 78.00 191.52 14,938.42

2.00 Internal plastering m2 200.00 4.63 926.84

3.00 Wooden door 220*90

no 10.00 184.00 1,840.04

4.00 Block 20*20*40 m2 100.00 15.95 1,594.70

Lecture 7Estimating & Evaluation

Form of evaluation based on cost per unitID Description unit Unit price

1 Concrete footings m3 200

2 Block 20*20*40 m2 20

3 Wooden door 220*90 cm no 300

4 Internal plastering m2 6

Cost per m2 of floor area(residential building)

Description (m2)

stores Ground floor

First floor

Structural elements

70 80 60

finishing 40 80 80

total 110 160 140

Cost of housing unit = cost of m2 * the areas of the unit

Analysis of quantitiesAnalysis to raw material quantities for example

:- Concrete : cement, water, aggregate, steel, - Cement in 1m3:- Mixing proportion (4:2:1) = 300kg, 6:3:1 =

200 kg, - 8:4:1 = 150 kg- 1m3 concrete = 80% aggregates, 40% sand- 1m3 (footings) = 60kg

Miscellaneous works1m2 block (40*20*20) = 12.5 block1m2 tiling (25*25) = 16 1 sack of cement = 1 m2 plastering1 sack cement = built 100 blocks

Estimation of Concrete price1 m3 concrete consist of :350 kg cement 1.2 ton aggregates0.8 ton sandPrice of mixing and pouring, transportationThe total price will be = 0.35

*300NIS+1.3*40+0.8*120+20 (mixing)

Steel reinforcement In general and according to practices, the

following elements contains , Steel reinforcement

Footings = 60kg/m3Columns = 200 kg/m3Ground beams, stairs,= 80kg/m3Slabs = 17kg/m2

Payment certificateFinancial Request for payment, prepared by

contractors, and approved by consultant / owner , describing the actual achieved works , by calculating the unit price by the quantity of item done.

It is important for the contractor as well as for the owner. For the contractor, he gets the value of works done, and save to him liquidity

for the owner , he become aware of the progress, achieved (actual) and planned, therefore, he can know if there is any obstacles or delay.

Preparation of payment

Types of payment certificates1- interim payment certificate2- final statement / final payment certificates

1- interim payment certificateIt is request for payment, contains quantity

survey for the accomplished works , and other supporting details submitted by contractor over the progress period of the project, .

The amount of each request should not be less than 10% of the contract value or according to contract conditions

Contents of the payment certificate1- Financial Payment Certificate: it is a survey

of the accomplished works (actual done), multiplied by its value according to the contract.

2- Measurements : 3- Drawings : as built drawings.

Content of the Payment Certificate

It contains :1- summary, describing the commencement date,

project end date, in addition to other data as contract value, variation order, percentage of the accomplished works, value of the current payment, and due payment, any amount to be deducted for retention, Percentage of retention stated in the Contract Data to the total of the above, and Retention Money (if any) stated in the Contract Data; any amounts to be added and deducted for the advance payment , the deduction of amounts certified in all previous Payment Certificates.

Payment Certificate2- total price of the accomplished works, and

percentage of the work done in relation to total project.

3- other supporting documents including the description of the items, progress in each item previously and also current, unit price, total percentage of the project progress.

Second : measurementsAnd it is table of actual quantity survey

accomplished, including item description, number, volume (length, width, height) and the total.

Third : As build drawings, describing the details of the work done,

Payment Certificate

Final payment certificateIt is called the final payment / certificate after

the primary taking over the project.The process of approval as follows:1- after taking over the project, final request

for payment is prepared, the contractor signed the request for

payment and the measurement sheet, and submitting it to engineer / owner.

2- to be paid the following documents should be attached :

Copy of taking over certificate signed form the committee

Copy of the bid submitted from the contractor after considering the prices in the request for payment

defect liability securityAll tests resultsDeduction of the works that mentioned in the

taking over or any liquidated damages.Letters of project extension if it was

extended.

Final payment certificateContents of the final payment certificate :Application for the requestList of the actual accomplished works and its

value.List of measurementsAs build drawings as it was approved from

the engineer.

Table of reinforcement steel weights :

Diam Wt of 1m length(kg) Area of section (mm2) Perimeter (mm)

6 0.222 0.283 1.884

8 0.395 0.502 2.521

10 0.617 0.785 3.14

12 0.888 1.13 3.768

14 1.209 1.539 4.396

16 1.58 2.01 5.024

18 1.999 2.543 5.652

20 2.468 3.14 6.28

22 2.986 3.799 6.908

25 3.856 4.906 7.85

28 4.837 6.154 8.792

32 6.318 8.038 10.048

36 7.996 10.174 11.304

40 9.872 12.56 12.56

Weight of 1m of steel bar = (diameter, cm)2 * 0.617

Area of section = π r2

Perimeter (mm) = 2 π r

Footing tableF1, C1F2, C2 F3, C3F4, C4

Length of steel Bars :F1 : 1.5 x 1.3 x 0.45 m, Reinforcement

= 11φ12 , & 9 φ12F2 = 1.7 x 1.5 x 0.45 m,

Reinforcement = 13φ12 , & 11 φ12F3 = 1.9 x 1.7 x 0.45 m, Reinforcement

= 14φ12 , & 12 φ12F4 = 2.1 X 1.9 X 0.5 m, Reinforcement

= 16φ12 , & 14 φ12Concrete cover = 5 cm

For F1: Length of steel in longitudinal direction: Ls = 1.5 - .05*2 =1.4 m In vertical direction at both sides = (0.45-0.05*2)/3 *2= 0.24 m The total for bar in longitudinal direction =

1.4+0.24+0.12*2=1.88 m The total length for all steel in longitudinal direction = length of 1

bar *number of bars in the direction = 1.88*11=20.57 m In traverse direction: = 1.3 – 0.05*2+0.12*2+0.24 = 1.68m Total length for all steel in the short direction = 9 *1.68 = 15.12

m The total in both direction = 35.69 m WT of steel for one foot type F1 = 35.69 * 0.888= 31.693 kg For all F1 = 31.693 *4 = 126.77kg.

ID Item description

unit Diam. Length of bar

Total length

Wt of 1m

Total Wt

No. of footings

Total WT for all F1

drawings

1 Reinforcement steel for footings :

F1 Kg Φ12 In long direction = 1.88

In short direction = 1.68

1.88*11+1.68*9 =

35.69 m

0.888 31.693

4 126.77

For column neck:

C1 = 25*60, 6φ14 (F1 : 1.5 x 1.3 x 0.45 m,

Reinforcement = 11φ12 , & 9 φ12)Length of one bar:Excavation depth = 1.5 m, floor

height = 0.48 mSteel leg = 1.5 – (0.05*2)/4 = 0.35

mThe total length = 1.5

+0.48+0.35+0.14 – 0.1 – 0.05 – 0.024 = 2.296 m

For stirrups:If length of column section <60cm, one

stirrup is needed, but if it is > 60cm, two ties is needed

Concrete cover for column = 2.5 cmFor C1 = 25*60Length of stirrups= (0.6 – 0.05)*2 = 1.1mWidth of stirrup= (0.25-0.05 )*2 = 0.4mTotal length of the stirrup= 1.1+0.4+0.08*2

= 1.66m

Specification & Quantities Estimating Lecturer Maha Muhaisen College of Applied Engineering& Urban...

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