1. GENERAL
This preamble is to apply to all Bills of Quantities in the Contract unless shown otherwise. The Bills of Quantities are to be read in conjunction with the conditions of Contract, the specification and the Drawings.
The rates and prices in the Bills of Quantities (comprehensively referred to as the Contract Rates) shall except in so far as is otherwise provided under the Contract be deemed to cover all obligations as set out in the contract, and all matters and things necessary for the proper completion and maintenance of the works.
A price or rate is to be entered against each item in the Bills whether quantities are stated or not. Items against which no price is entered shall not be entertained and may lead to bid disqualification. All rates or prices are to include fixing unless otherwise distinctly described. Whilst every care has been taken to ensure the accuracy of the Bills of Quantities, the Contractor is advised that he should order materials sufficient for the works shown on the drawings. Claims, which arise from failure to comply with this recommendation, will not be considered.
The Quantities set forth in the Bills of Quantities are believed to represent the character of the work to be carried out. There is no guarantee to the Contractor that he will be required to carry out the quantities of work indicated under any one particular item or group of items in the Bills of quantities, though on the contract as a whole, the quantities are believed to represent the overall value of the work to be carried out.
The prices and rates inserted in the Bills of Quantities will be used for valuing the work executed and the Engineer will measure the whole of works executed in accordance with this Contract.
The prices and rates inserted in the Bills of Quantities are to be the full inclusive costs of the works described under the items, complete in place and in accordance with the Specifications, including costs and expenses which may be required in and for the construction of the works described, together with any temporary works and installations which may be necessary and all general risks, liabilities and obligations set forth or implied in the documents on which the Contract is based.
The brief description of the Items given in the Bills of Quantities are purely for the purpose of identification and in no way modify of supersede the detailed descriptions given in the Conditions of Contract or specifications. When pricing Items, reference is to be made to the Conditions of Contract, Standard Specification and Special Specification for the full directions and description of work and materials.
No alteration shall be made to the Bills of quantities or Scheduled of Basic Rates and extra Item shall be inserted. The tenderer shall satisfy himself that the contract Sum arrived at by pricing the quantities items given is sufficient compensated for constructing and maintaining the whole of the works in accordance with these Contract Documents.
The Bill of Quantities has been drawn up in accordance with the standard method of Measurement published by the Institution of Civil Engineers, London.
When special methods of measurement have been employed these are referred to later in this preamble or are apparent in the item description in the bill of quantities.
The item descriptions are only given in sufficient details to enable the identification of the item referred to and the Contractor must refer to Drawings, Specification and Conditions of Contract for detailed information and general obligations.
3. Bulk Excavation
The measured volume of bulk excavation shall be the net plan area of the foundation or base structure to be built multiplied by the mean depth. The depth shall be taken from formation level.
The rates for excavation generally are to include for:-
(i) Additional excavation beyond the net size of the structure whether for working space, timbering, shoring or other temporary work or for any reason whatsoever, and for any consequent refilling with suitable materials.
(ii) Multi-handling and transporting to temporary spoil heaps as may be required.
(iii) Supporting and maintaining the sides of excavation by any means including planking and strutting, trench sheeting and sheet pilling, and making good any slips or falls to the satisfaction of the engineer.
(iv) Pumping, dewatering, ground-water lowering and any other temporary provisions which may be necessary to carry out the work and keep the formation and excavation free of water from whatever cause arising unless as specified item is included in the Bill of quantities.
(v) Trimming to finished dimensions, battering to slopes and such additional items as may be necessary to complete the excavations.
(vi) The disposal of surplus material. 4. Trench Excavation
Unless otherwise and only if required doing so, excavation for trenches shall be measured in cubic metres. The item descriptions in the Bills state the width of the trench.
The depth of trenches for pipes, will be measured from the existing ground level, except that where trenches are excavated subsequent to the execution of bulk excavation the depth will be measured from the surface level. All depths denoted in the bills of quantities are measured to the invert of the pipe. The contractor must allow in this rates for additional excavation for pipe bedding as shown in the Drawings.
The rates from trench excavation are to include:- (a) (I) and (vii) as stated under bulk excavation above.
(b) Final hand excavation and trimming of the trench bottom and additional excavation for joint holes, etc.
(c) Providing, placing and compacting selected trench fill material, filling and compacting the remainder of the trench with excavated material and carting away and disposing of surplus material.
5. Excavation in Rock
Provisional Bill items have been included where excavation may be in rock. The rates from these items shall include all labours involving rock excavation including carting away or otherwise disposing of rock. Measurement will be net in cubic meters as described for excavation and no allowance will be made for over break.
6. Filling
Materials arising from the excavation, where suitable and approved by the Engineer, are to be used as fill around the works and will be paid for as such under the items provided therefore.
No allowance will be made for the bulking of materials after excavation and filling will be measured as equal to the voids to be filled. All thickness measured or stated are those after compaction.
The rates for filling are to include for:
(i) Selecting and grading the materials for the purpose for which it is to be used.
(ii) Breaking down any rock arising from the excavations to a suitable size for re-use as filling where approved by the Engineer.
(iii) Multi-handling and re-excavation from temporary spoil heaps as may be required. (iv) Depositing in layers and compacting as specified.
(v) Making good all settling except where otherwise provided for in the specification. 7. Shuttering:
The rates for shuttering generally are to include for provision of the shuttering and for:-
i) Cleaning, oiling, erecting and stripping and for all necessary ties, spacers, struts and supports. ii) Splayed edges, notches and forming chambers not exceeding 50mm wide.
iii) Removing any flashes or ridges left after striking.
iv) Making good any blemishes to the smooth surface of the concrete.
8. Concrete
The rates for concrete are to include for provision of the concrete and for:
i) Float finish to all unformed surfaces of concrete unless otherwise specified and finishing to falls where required.
ii) Formwork in the formation of all construction joints.
iii) Vibrating, curing, brushing and cleaning at construction joints and other work as described in the specification.
Joints with water bar and sealant in grooves that are required for structural reasons are billed. The cost of supplying and fixing all materials required at construction joints such as water bar and sealant that are required to ensure a watertight structure should be included for in the rates for concrete. 9. Pipe work
The rates for laying or installing, and jointing pipes, fittings and valves are include for the supply and delivery of materials not covered by Prime Cost items, receiving, inspecting, unloading, storing, distributing, installation, or laying, jointing, cleaning, plugging, repairing, or replacing damaged pipes and other materials and carrying out all surface unless billed separately.
The rate for laying pipe work shall include for all labour, water, plant, equipment and materials necessary for carrying out testing, cleaning and in the case of water supply disinfecting the pipe work. Farmers will excavate and backfill all trenches where such activity is possible by hand (manual) tools.
Concrete bedding, surrounds and anchor blocks etc, will be measured in cubic metres, the rates for which shall include for any shuttering required and additional excavation necessary outside the normal trench limits, unless otherwise stated in the Bill of Quantities. Rate to include for supply of Denso Tape or similar approved material and for wrapping the pipe with the tape to prevent a bond between the concrete PVC pipe, all to the satisfaction of the Engineer.
Where not specified, pipe dimensions/working pressures shall conform to KS-06-146: Part 2, 1991 for uPVC and BS 1387 for G.M.S. or equivalent.
10. Manholes
The rates of manholes must allow for the provision of a complete manhole as shown on the Drawings and described in the Bills of Quantity and Specification Rates to include for all additional excavation necessary to facilitate construction, all backfilling required and carting to tip all surplus spoil. Depths noted in Bills of Quantities are from existing ground level to invert of pipe and Contractor must allow for all additional excavation for base of manhole and Contraction to cover levels shown on the drawings.
11. Abbreviations
The following abbreviations for units of measurement have been used in the Bills of Quantities:-
Unit Abbreviation Millimeter mm Linear Meter M Square Millimeter mm2 Square Meter M2 Cubic Meter M3
Hectare
ha
Kilogramme Kg Sum Sum Number No. Hour hr Week wk Tonne tMarker and Indicator Posts
(1) The Contractor shall erect indicator Posts and marker posts on the routes of pipelines as directed. He shall also erect indicator posts bedded in concrete.
(2) Marker and indicator posts shall be vibrated precast reinforced concrete conforming to the dimensions and patterns shown on the Drawings with concrete grade 20, using 10mm aggregate, Class A Finnish.
12. Prime Cost Items
Where a prime Cost (PC) item is inserted in the Bills of Quantities for the supply of goods, materials or services for the works, it is intended to cover the actual cost to the Contractor for such articles or services including delivery, after deduction of all cash discounts as invoiced by the suppliers subject to the provisions of Clause 58 (5)
The Contractor shall, when directed, obtain quotations with detailed plans and specifications from approved suppliers and submit them to the Engineer for approval. Alternatively, the Engineer may obtain quotations. On receipt of written instructions from the Engineer, the Contractor shall place the orders for such goods, materials or services. No expenditure shall be incurred by the Contractor except under the written authority of the engineer.
When a PC Item is to be used for the execution of work, it is intended to cover the actual cost of the works as certified by the Engineer and payment shall be made in accordance with the provisions of Clause 59 (2) and 60.
Sub-item (I) following the PC Item shall be a sum for the Contractor’s labours in connection therewith which shall be deemed to include:-
Any case in which the Nominated Sub-Contractor is to carry out work on site, only for affording every facility to enable the proper execution of work by the nominated sub-contractor to proceed without interruption f the orderly progress of the Works, allowing such persons the use free of charge of all erected scaffolding, plant, ladders, etc required, unloading or assisting in unloading distributing and hoisting to position if required of the sub-Contractor’s plant and materials, sorting, re-addressing and returning all crates, packing materials, etc. carriage paid and for providing space for office accommodation and storage of plant and materials and for providing water, watching lighting protection and welfare facilities, etc.
Sub-item (ii) shall be deemed to include for:-
Any case which the Nominated Sub-Contractor is not to carry out work on the Site and except when specifically billed only for deliver, unloading, sorting, inspection, repairing or replacing damaged items, storing, distributing and hoisting materials supplied by the Nominated Sub-Contractor, and re- addressing and returning all crates, packing materials, etc, carriage paid.
Sub-item (I) and (ii) following the PC Items shall be expressed as a percentage of the actual price paid or due to be paid in respect of the PC Item and shall cover all other charges and profit. Payment shall be made in accordance with the provisions of Clause 58 (5).
In any case which the goods, materials or services supplied by a Nominated Sub-Contractor are to be used, erected or installed by the Contractor, the sum inserted in the relevant item or items to cover such use or erection shall be deemed to include for jointing and testing where appropriate all such goods, materials or services and for the cost of all labour, materials, use of plant and tools, forming or drilling bolt holes, chases and the like, and for grouting in or concreting in parts and making good to complete them in full working order and for maintaining them, keeping them clean and operating them during the period of the Contract.
13. Demolitions and Site Clearance
Except where otherwise particularly described the whole of materials, fittings, debris, rubbish and vegetation arising from demolition work and clearance of the site are to become the property of the contractor who is to remove them from the site. The rate of site clearance shall include for such disposal.