|Section 2.1||Preliminary and General|
|Section 2.5||Timber and Cladding|
|Section 2.8||Plumbing and Drainage|
|Section 2.10||Mechanical Equipment|
|Section 2.12||Equipment List|
2.1.1 SCOPE OF WORK
The work comprises the construction of (i) a Modular Abattoir complex and (ii) a Meat Market. The scope of work for each is similar; viz.,
Preparation of the ground by forming to level and grade and excavating locally for foundations or, if necessary, by excavating unsuitable fill material and replacing with imported compacted backfill.
Shaping of ground to suit footings and floor slab layout and falls and to allow exterior ground drainage.
Laying and backfilling over underground and underfloor drains. *
Boxing foundations and placing reinforcing with column starter bars.
Pouring of slab and footings and curing.
Construction of unreinforced masonry infill panels.
Placing reinforcing, boxing, and pouring columns.
Placing reinforcing for lintel beams and pouring concrete.
Casting in bolts and anchor plates as necessary in the columns and lintels.
Fabrication and fixing roof trusses and bracing.
Placing and fixing purlins.
Fixing roof cladding, gutters and downpipes.
Wall framing with cladding panels and insect mesh as necessary.
Fixing of external rails for sliding doors. *
Placing and fixing internal beams for meat rails plus fitting rails and hangers. *
Constructing weather covers for sliding door rails. *
Hanging of hinged doors. *
Internal wall and floor plastering as required.
Painting as required.
Supply and/or manufacture and installation of mechanical plant. (Including prefabricated chiller unit, lairage fences and gates etc).
Construction of external effluent disposal system *
Construction of solid waste disposal systems. *
* These items are not common to both buildings.
2.1.2 PROTECTION OF WORKS
The contractor shall at all times ensure that the site is secure and safe. For this purpose he shall provide the necessary fencing, hoardings and lighting, and a nightwatchman if deemed necessary.
Temporary scaffolding erected for construction use shall be of adequate strength and securely braced to meet local requirements.
2.1.4 MATERIALS AND PROPRIETARY PRODUCTS
All materials to be used in the buildings shall be first quality and free from defects. All proprietary products, processes, and materials specified and detailed for use in the works shall be in strict accordance with the manufacturer's instructions.
Products are to be delivered to site in the manufacturer's original boxes or wrapping.
2.1.5 SETTING OUT
The contractor is responsible for setting out the work in relation to level, line, dimensions, squareness, and vertically.
2.1.6 REGULATIONS AND BYLAWS
The contractor shall arrange for any inspections, permits, notifications etc required by the relevant Government or Local Authority.
2.1.7 TEMPORARY DRAINAGE
The contractor shall ensure that temporary drainage measures e.g. trenches or piping are provided to ensure that the site will not flood during heavy rainfall.
2.1.8 ABATTOIR ROOF TRUSSES
Both timber and steel trusses have been detailed for the roof trusses. The contractor may construct either the steel or the timber trusses but not a mixture of both types.
2.2.1 SITE SOIL CONDITIONS
Wet, swampy ground will not be satisfactory for founding buildings of this type. If necessary surface or subsoil drains shall be formed to ensure that the foundation soils do not become saturated. All organic topsoil shall be removed.
2.2.2 FOUNDATION TESTS
The suitability of the foundation soils can be tested by probing with a pointed steel rod of about 12mm diameter by 2m long.
Adequate bearing for the building will be indicated when the rod can be pushed by hand only about 100mm at the most into the proposed founding layer.
Further testing of the soil layers must be done by driving the rod using a 5kg steel hammer to a depth of 1m to expose any softer layers of material below the founding level.
A pit approximately 1.5m deep should be dug to study the underlying material at first hand.
There shall be no soft layers as defined by the rod test above or within 1m of the founding level.
A standard Scala Penetrometer should be used for soil testing when available. Tests should be carried out to a depth of 2m and acceptable bearing is indicated by a resistance to driving of 2 blows or more per 75mm in the top 1m of foundation material. The lower 1m should not have a count of less than 1 blow per 75mm.
2.2.3 INADEQUATE GROUND CONDITIONS
Should the site not meet the criteria given above and if no other site is available then the subsoil material shall be excavated to a depth of 750mm below founding level and replaced with compacted fill material.
The preferred fill material is a hard rocky gravel of maximum size 100mm and containing some sand but no clay or silt.
A clay fill may be adequate if carefully compacted with the water content controlled to suit the particular material being used. Subsoil drains should be installed at this time.
Sand of size 5mm down is suitable if it is compacted using a controlled amount of water, and subsoil drains are provided.
Compaction of fill material shall be done in layers not exceeding 150mm thick. Compaction of gravels and sands can be done using a minimum 1 tonne weight steel wheel roller. Compaction of the clay can be done using a small projecting foot roller, and shall not be done in wet weather.
Where mechanical equipment is not available compaction shall be by heavy hand held rammers eg 125mm diameter by 2m long hardwood poles.
Tests using the penetration requirements listed above for adequate bearing strength shall then be made.
2.2.4 LOCAL EXPERIENCE
Local advice should be sought as to the suitability of material, particularly clays, for building foundations. The usual construction methods should be ascertained and adjacent buildings studied. Road cuttings can provide useful information about soil strata.
2.2.5 PREPARATION FOR CONSTRUCTION
Following subsoil preparation as necessary (above) the site should be level and smooth over the building area with no organic material, sticks, or large rocks. The prepared ground is effectively the lower formwork for the floor slab and foundations so great attention must be paid to obtaining a smooth and level surface.
The outside perimeter is located using string lines set up from pegs offset from the building corners by 1m, e.g. the outside dimensions of the floor slab/foundations for the Abattoir building is 4200 x 6000mm therefore corner offset pegs will be at 6200mm and 8000mm centres, the diagonals should then both measure 10121mm.
Excavation for the footings shall be made as shown on the drawings. Only the outside face of the footing is to be boxed. The underside of the footing can be poured against shaped ground. Excavation for these footings shall be made to a tolerance of +30, -10mm and the deviation from straightness in 1m shall not exceed 15mm.
The formed platform for the floor slab shall not differ from level by more than 15mm over the four corners and centre. The formed platform shall be shaped to provide the falls shown on the drawings and drainage pipes bedded, laid, and backfilled as necessary.
The tolerance on slab thickness shall be 100–125mm and the straightness deviation of the prepared ground 15mm over 1m.
As an alternative to shaping the ground to form the drainage falls a flat platform may be used and the slab varied in thickness to suit. Minimum thickness of slab is to be 100mm. Final slab surface falls shall be correct to ± 5mm over 1m.
Where the sub-base is composed of rocky material (maximum size greater than 15mm) a sand blinding layer shall be used approximately 50mm thick under the slab and footings, to provide an even, smooth surface.
A 0.25mm thick polythene sheet damp course shall be laid under the slab to the edge of the footings as shown on the drawings. Joints in the polythene shall be made by lapping 100mm and sealing both edges with plastic tape. Any holes made during construction shall be repaired by patches with minimum of 100mm overlap.
The section of the specification covers the supply, placing, and finishing of all concrete.
Standard Portland type cement shall be used, from a recognised supplier or manufacturer. Cement shall comply with BS12 or an equivalent standard. The bags are to be delivered to site unopened and must be stored clear of the ground and under waterproof covers.
Any bags showing signs of water contamination or of having been opened shall be rejected and removed from the site.
The coarse aggregate shall be hard, clean, non-absorbent stones either crushed or uncrushed. Aggregate shall comply with BS882 or an equivalent standard where possible. Local experience with strength and durability of concrete structures should be called on to determine a satisfactory source of aggregate.
Maximum aggregate size shall be 20mm. The coarse aggregate shall be graded such that there is an even size range from 20mm down to 5mm and that there is not a predominance of a particular size.
The fine aggregate shall be a graded sand from 5mm down to approximately 0.15mm of similar material to that used for the coarse aggregate. An excess of fine particles must be avoided.
The aggregates, both coarse and fine, shall be entirely free from silt or organic material and shall be thoroughly washed with fresh water either at the quarry or at the site to ensure this requirement is met and that any salt contamination is removed.
Aggregates shall be stored on site on an impervious mat eg. plastic or galvanised iron sheets and where necessary protected against livestock access.
Water to be used in the concrete mix shall be of quality that would be acceptable for drinking although some bacterial contamination need not be cause for rejection.
Seawater or any water with taste detectable salt content shall not be used.
2.3.5 CONCRETE MIXES
|Floor Slab:||Weight per Cubic * Metre||Proportions by * Volume|
|Water||130 litres or kg||0.5|
|Water||150 litres or kg||0.5|
* These mix ratios assume that the sand and aggregate isdamp ie. the sand can be moulded in the hand by squeezing.
A power mixer of minimum capacity 50 litres should be used. The concrete mix weight can be found by dividing the weights per cubic metre given above by the fractional mixer capacity i.e. 50 litres is 1/20 of 1 cubic metre therefore divide the given weights by 20.
Cement should be weighed but can be volume measured in a marked bucket if it is initially weighted to calibrate the bucket. Shovels shall not be used for measuring quantities.
Aggregate can be measured by bucket or other container. The proportions by volume in the chart give the number of container loads of each component of the mix.
2.3.7 MIXING PROCEDURES
Place 3/4 of the water in the mixer
Place 3/4 of measured aggregate (fine and coarse) in the mixer.
Place all the measured cement in the mixer.
Place remaining aggregate in mixer.
Mix for 2–3 minutes while adding only enough additional water to produce a consistent looking mix. Use as little water as possible.
2.3.8 SLUMP TEST
If the equipment is available, a standard slump test shall be carried out on every fourth mixer load. The maximum acceptable slump is 100mm.
2.3.9 PLACING OF CONCRETE
Concrete should be transported from the mixer to the point of placing with the minimum of jarring. Runways should be made for wheelbarrows.
The preferred compaction methods are a mechanical vibrating screed for the floor slab and poker vibrators for the columns, foundations and lintels.
Poker vibrators can be used for the slab if a mechanical screed is unavailable.
If no mechanical equipment is available then the slab shall be compacted using a heavy tamping screed board with an operator at each end.
Columns shall be poured in lifts of 2m maximum.
If poker vibrators are not used for compaction in the columns then special care is necessary in using hand tamping rods to ensure adequate compaction. Inadequate compaction will be clearly visible as ‘honeycombing’ when the formwork is removed. Faulty work shall be repaired only on the Engineer's instruction.
2.3.11 SURFACE FINISH
A non-slip surface can be obtained on the floor slab by lightly finishing with a broom. This work should be done after surface water has evaporated following screeding.
Concrete slabs shall be cured by one of the methods following. The preferred method is to form a clay dyke around the edge of the slab and then pond the slab with water to a depth of about 30mm.
Alternatives to this method are constant light sprinkling with water or hessian sack coverings that are kept continuously moist. A plastic sheet can also be used to seal water into the slab area.
If sprinkling or soaked hessian is used it is essential that the concrete is left moist at all times and not allowed to dry out.
All curing procedures must be continued for at least three days and preferably longer. Inadequate curing will be evident later as surface cracking
2.3.13 HOT WEATHER CONCRETING
Concrete mixing and placing shall not be carried out when the shade temperature exceeds 30°C. If this temperature is exceeded during the hot period of the day work shall be commenced early in the morning or late evening so that materials shall be as cool as possible.
Care should be taken to avoid excessive mixing. The placing of the concrete must be done as quickly as possible after mixing.
Use of a fog spray as soon as the concrete is screeded will maintain moisture content without causing surface damage.
Curing must be continued for a least six days. The concrete surface must not be allowed to dry out.
Concrete shall not be placed when there is a likelihood of rain which would damage the surface finish or cause ponding in the formwork.
2.3.15 STRENGH TESTS
Wherever possible, standard concrete cylinder test samples shall be taken (3 for the floor slab and foundations, 6 for the columns).
These samples shall be prepared and tested in accordance with BS1881. The specified concrete strength to be attained is 25MPa.
Formwork shall be sufficiently strong to support the forces imposed by the weight of concrete. In addition it must be rigid enough so that distortion is kept to a minimum. This particularly applies to column formwork where deflection will produce obvious misalignment of the columns.
Galvanised wire through–ties can be used for column formwork bracing. These ties are later to be broken off beneath the concrete surface and the surface made good with mortar.
Formwork for columns and foundations should be a minimum 10mm thick plywood backed by 100 × 50 blocking. 200 × 25 timber may be used instead of plywood. Formwork to footings and foundations must be braced back to firmly driven pegs, at least 50 × 50 square by 400mm long.
2.3.17 PLACING OF REINFORCEMENT
Reinforcing steel shall be bent, tied, and placed as shown on the drawings. Reinforcing steel to beams and footings must be supported on concrete chips to maintain the cover to ground.
Reinforcing bars shall in general be placed within 10mm of their positions detailed on the drawings.
It is essential that the reinforcing bars be securely tied to themselves and to the formwork if necessary so that their correct position is maintained during placing and compaction of the concrete.
Concrete cover over the reinforcing steel must be maintained so that no later corrosion at the reinforcing occurs.
2.3.18 READY MIXED CONCRETE
Production batch mixed concrete delivered by a revolving drum mixer truck may be used instead of site mixed concrete.
The batching plant must have a current certificate from a recognised certifying authority.
Concrete properties to be supplied are:
Strength 25MPa @ 28 days
Maximum slump 100mm
Maximum water/cement ratio 0.6
Concrete cement content to be in the range 300–340kg/m3
Maximum aggregate size 20mm
Slump and cylinder strength tests shall be carried out either at the plant or on site.
Construction joints shall be kept to a minimum.
Where new concrete is to be poured against a stop end the green concrete shall be broken back approximately 15mm using hand chisels or power hammers to expose fresh hard concrete.
For the column construction joints special care must be taken. The green concrete below must be broken back at least 20mm to sound material and all loose particles and dust removed before the new pour is started.
Joints shall be formed in floor slab where shown and as detailed.
2.3.20 CAST-IN ITEMS
All bolts and brackets shown as cast-in place on the drawings shall be accurately set and fixed in place before any concrete is poured. Fixings must be secure so that vibration of concrete does not cause any movement.
All cast-in steel items shall be hot dip galvanised.
This section covers the supply and fabrication of steel trusses, meat rails and hangers, door rollers, and miscellaneous nuts, bolts, and plates. Reinforcing steel is also included. Where British Standards are quoted in this section other recognised national equivalent standards may be used.
Structural steel rolled sections and plate shall comply with BS4360 grade 43A or an equivalent standard with maximum sulphur content 0.05% and with a minimum yield strength of 250Mpa. Material with a specified yield strength above 330Mpa shall not be used (i.e. high tensile steels are prohibited).
Bolts and nuts shall be either ISO metric thread, or UNC threads if equivalent imperial sized bolts are used. ISO metric bolts shall comply with BS4190, UNC with BS1768, and shall have a minimum yield strength of 250Mpa. Washers must be compatible with bolts used. All nuts, bolts, and washers shall be hot dip galvanised to give an equivalent coating weight of 300gm/m2 and be fabricated with thread clearances to suit the galvanising process.
Electrodes shall comply with BS639 and be appropriate to the parent metal being welded. Electrodes must be used only within 6 months of manufacture. Electrodes shall only be used which have been stored in dry conditions in accordance with the manufacturers recommendations. Any electrodes having areas of flux covering damaged in any way shall not be used. Shorting of electrodes to earth is prohibited. Any electrodes which become damp shall not be used.
Reinforcing rod is to be either deformed bar or round rod as shown on the drawings.
Reinforcing steel shall be ‘Standard Grade’ and have a specified yield strength in the range 250 – 330Mpa. High yield bars shall not be used.
Reinforcing rod shall comply with BS 4449.
Equivalent imperial sized bars may be used in place of the metric sized bars shown on the drawings.
Reinforcement shall be free of oil, grease and loose scale or rust. Firmly bonded surface rusting is acceptable.
2.4.3 WELDING EQUIPMENT
All welding plant and equipment, and protective equipment, shall comply with BS638. The steelwork fabricator shall supply adequate means of measuring the welding current as part of the welding plant or separately in the form of a separate ammeter.
Welding plant must have sufficient capacity (amperage) for the size of rods being used.
The fabricator shall make his own shop drawings as he requires to enable accurate work in his own workshop.
All material before being assembled shall be straightened as necessary and shall be free of twist. Any straightening methods used shall be such that the steel is not injured. Any heat applied shall be the minimum necessary for the purpose required.
Cutting may be by shearing, sawing, or machine gas cutting. Hand gas cutting may only be used when it can be demonstrated that clean, consistent, undistorted edges can be produced.
Edges shall be dressed with file or grinder to give a neat and workmanlike appearance, free from burrs.
The building up of plate edges with weld metal is prohibited.
|Sizes of plates and brackets||± 2%|
|Position of bolt holes||± 1%|
|Straightness of trusses over full length||± 10mm maximum|
|Truss dimensions : length||± 5mm|
|Steel purlins over 2m||± 5mm maximum|
Welding shall only be carried out by experienced operators. Welding procedures shall be in accordance with BS5135.
Operators shall be qualified for the welding position or positions they undertake.
Fusion faces shall be cleaned by wire brushing or grinding before work commences. Only minor rust or firmly adhered mill scale shall be present on the faces to be welded.
2.4.9 WELDING INSPECTION
The fabricator's welding equipment and workshop procedures will be subject to approval.
Welds will be visually inspected and tested by the dye-penetrant method as considered necessary.
2.4.10 BENDING OF REINFORCING STEEL
All reinforcing steel shall be bent cold around formers of the correct diameter.
The internal radius of bends shall be 2.5 × D where ‘D’ is the nominal bar diameter. R6 stirrups may be bent to an 8mm internal radius.
Any laps required not detailed on the drawings shall be 25 × D in length.
Bars are to be bent to a tolerance of ± 5mm on length, except for column stirrups which shall have a tolerance of ± 3mm on a side.
2.4.11 PAINTING OF STEELWORK
All plates, rolled sections, rods, and cast-in angles are to be painted (including door frames if made in steel).
All cut edges shall be slightly ground or filed to ensure that no sharp corners exist which could cause the paint coating to be excessively thin.
The preferred method of cleaning is by sand or grit blasting. Hand cleaning using scraping, sanding and wire brushing will be acceptable provided it is done thoroughly e.g. it is expected that cleaning a steel truss by hand would take at least 4 man hours. Hand cleaning shall be followed by a proprietary phosphoric acid rust inhibitor, used in accordance with the manufacturer's instructions.
Oil and grease must be removed before any preparation work commences using either turpentine or petrol, and clean rags.
Only paints from new, fresh tins shall be used, strictly in accordance with the manufacturers recommendations. A zinc based anti-corrosive primer shall be applied by brushes to give an even coating of the recommended thickness. This work to be done in the workshop.
Two enamel top coats (colour white) shall be applied to all steelwork except cast-in brackets and plates.
All painting must be carried out under cover and in weather conditions that will allow satisfactory drying and curing of the coating.
Painting may also be done by spray equipment provided the work is carried out by experienced operators.
This section covers the supply of timber cladding materials and shop and site carpentry.
Doors shall be manufactured in a joinery shop and delivered to site. Building, framing and detail work shall be cut and measured on site to suit.
Timber roof trusses may be either shop or site fabricated.
2.5.2 SPECIFIED TIMBER
Locally produced timber may be used for all work. Only a source of supply that has proven satisfactory for previous buildings should be considered. Only new timber shall be used.
For the design of trusses and beams the following basic design allowable stresses have been used:
|Tension parallel to grain||5Mpa|
|Compression parallel to grain||7Mpa|
|Modulus of elasticity||8 × 103Mpa|
These allowable stresses are applicable to Radiata Pine and other lower grade structural timbers.
PERMISSIBLE SIZES OF DEFECTS
|Sound Knots||Defective Knots and Knot Holes||Sloping Grain|
|Beams & Purlins (inc. truss beams)||1/4W, 1/3T||1/4W, 1/4T||1 in 12|
|Studs||1/2W, 1/2T||1/3W, 1/3T||1 in 8|
|Door frames||1/6W, 1/6T||None||1 in 15|
T = Thickness of section
W = Depth of section
Minimum spacing between defects at maximum allowable size is 900mm.
Door cladding in timber shall have no defective knots or holes.
Borer holes or pinholes less than 5mm diameter are acceptable if spaced greater than w/2.
Splitting and sapwood is acceptable only in wall studs and framing.
The allowable maximum moisture content at the time of installation is 17% for beams, purlins and door framing, and 20% for studs and wall framing.
2.5.3 TIMBER TREATMENT
Except where naturally resistant timber is used all timber to be used in the construction shall be pressure treated against rot and insect attack.
Pressure treatment shall be in accordance with BS 4072 ‘Wood preservation by means of water-borne copper/chrome/arsenic compositions’ or other equivalent national standards.
All timber shall be treated to a level appropriate to occasional exposure to the weather.
Timber shall be marked at the factory with the code relating to the treatment it has received.
2.5.4 TIMBER SIZES
Sizes shall be as detailed on the drawings but larger sections may be used provided other dimensions and clearances are not affected. Roof truss beams and lifting beams may be made from single sections if available.
All timber shall be gauged to produce a smooth plane surface. Studs and framing sizes shown on the drawings are nominal and gauged sizes approximately 5% less in depth and width may be used.
All timber on arrival at the site shall be stacked on bearers clear of the ground and with transverse spacer blocks so that no two layers are in contact. The stack shall then be covered and protected from wind and weather.
Galvanised flat head nails shall be used throughout. Three sizes of nail shall be used:
60mm for timber up to 25 thick
100mm for timber up to 50 thick
115mm for skew nailing
Nails shall be of a high tensile type from a reputable manufacturer, in marked boxes or packets. Nails of unknown origin or low tensile (bending) strength are not acceptable.
All bolts, nuts and washers shall be hot dipped galvanised.
Roofing screws shall be either galvanised or cadmium plated types.
Nails shall not be used for roof fixing.
Top and bottom plates shall be in long lengths and except where detailed otherwise shall be laid flat and shall be halved at all joints and junctions. Where not continuously supported block plates at all joints. Bottom plates shall be bolted to lintel beams as detailed on the drawings. Studs shall be of accurate length with ends cut square and shall be firmly attached through plates etc with not less than three nails at every contact. Nail through the plate to the stud.
Studs shall generally be placed to relate to the fixing requirements of the external lining.
All nails in laps, halving etc of framing timbers shall be 115mm long and shall have the ends bent over and clinched.
Double skew nail framing timbers at all intersections.
Drive all nails in framing so the head is flush.
Purlins shall be fixed to the timber truss top chord either by blocks or skew nailing (end walls only).
Blocks are to be secured to the purlin and to the truss with 3 × 100mm nails each. Skew nailing to the end plate (on flat) shall be done using 4 × 100mm nails.
2.5.9 DAMP COURSE
Protect all timber wherever in contact with concrete or masonry with a full width continuous D.P.C. of 3 ply maethoid or other approved material.
2.5.10 VERMIN STOPS/INSECT SCREENING
All means shall be adopted by inserting plates and stops to prevent vermin from gaining access to the building. Where insect screening is called for this shall consist of nylon insect mesh securely fixed to 150 × 50 reinforcing mesh with galvanised tie wire. Edges shall be finished with a screw fixed beading strip where possible (all galvanised).
2.5.11 DOOR FRAMES
Workmanship shall be equal to best trade practice. Joints shall consist of members housed into each other in preference to butt joints (i.e. use morticed joints). Fixings shall be with pins or screws as appropriate. All joints shall be screwed as well as having a mechanical fixing. Pins shall be punched and stopped.
Timber for door frames shall meet the requirements noted above but also shall be specially selected for straightness and lack of twist. Any members showing signs of warping during drying shall not be used.
The final work shall be free of all blemishes such as splits, shakes, twists and bruises.
2.5.12 PAINTING OF DOORS (TIMBER CLAD)
Both sides of the door shall be painted. Prepare the surface by sanding and scraping as necessary. Prime with alkyd (oil-base) primer and then fill holes and defects on the exterior face with linseed-oil putty. Top coats to be two coats of high-gloss exterior paint, either alkyd or acrylic, colour white.
2.5.13 DOOR HARDWARE
All sliding doors are to be fitted with a “D” type handle and hasp and staple for locking on the outside. A “D” type handle, within the door thickness shall be provided on the inside.
Hinged doors shall be fitted with a “D” type handle on each side, hasp and staple on the outside, and a tower bolt on the inside. Hinges shall be strap type.
Lift up shutters in the meat market shall be fitted with tower bolts on the inside to enable them to be locked down and hooks as detailed to secure them in the up position. Hinges shall be strap type, two per section.
All door hardware shall be galvanised.
Corrugated galvanised steel shall be used. Minimum steel thickness shall be 0.4mm. Corrugations shall be 17mm deep and 75mm wide peak to peak. Sheeting with corrugation dimensions within 10% of these figures is acceptable.
The base steel material shall have a minimum yield strength of 450MPa and shall be hot dip galvanised to give a minimum zinc weight of 200gm/m2 on all surfaces.
Only sheeting from a known and recognised source may be used. Alternatively low tensile steel sheet (250MPa yield) may be used if minimum thickness is 0.55mm.
Bundles of sheets shall be delivered dry to the site and stored on timber blocking and covered with canvas or waterproof material. Plastic sheet should not be used unless special care is taken to ensure that condensation does not occur.
Sheets shall be laid in one piece from apex to eaves. Cutting of sheets shall be by means of heavy shears to leave a clean straight edge. An eaves capping piece shall be used with lead edging which shall be pressed into the sheet corrugations carefully to give a complete weather seal.
Sheets shall be side lapped 11/2corrugations with the overlap away from the direction of prevailing weather were possible.
Fixing to timber purlins shall be by 75mm long screw type fastenings through the crest with neoprene sealing washers. Leadhead nails shall not be used. Fixing to steel purlins shall be by special self drilling, self tapping screws or hook bolts with sealing washers.
Fasteners shall be driven at every 3rd crest for intermediate purlin fixings and at every 2nd crest at eaves and apex purlins, plus at side laps. All fixings shall be hot dipped galvanised.
Bitumen coated tape 50mm wide or similar damp proof course material shall be laid along the purlins before fixing sheets.
After all nailing and flashing work is complete the roof shall be scrubbed down with clean water and any loose metal particles removed.
2.5.15 WALL CLADDING
Sheets to be used shall be asbestos cement or equivalent fibre cement board 7.5mm thick nominally. Sheets shall be delivered to site in packages clearly marked with the manufacturer's name and a description of the product. Sheets shall have a density at dry moisture content in the range 9 to 12kg/m2. Sheets are to be 1200mm wide and long enough to span from eaves to lintel beam without horizontal joints.
Store sheets on site as specified for the roof cladding. Take care with bundles of sheets to ensure edges are not damaged.
Cut sheets with fine tooth hand saw or power saw with diamond tipped blades.
Lay out sheets with even gap between edges of 1–2mm. Use neoprene sealing strip 40mm wide behind joints. Sheets shall be continuous from roof to lintel beam i.e. there shall be no horizontal joints.
Nailing shall be done with galvanised clouts 40mm × 2.5mm with large head, minimum diameter 7mm. Nail at 150mm centres on outsides and also for intermediate studs. Use extra nails at corners at 50mm centres approximately. Nails shall be between 12 and 20mm from the sheet edge.
Plastered masonry is to be used for the infill panels to the walls. Masonry wall sections shall be constructed before the columns are cast to ensure an adequate bond between the two materials.
Hollow concrete blocks or solid fired clay bricks may be used. Hollow concrete blocks shall be a minimum width of 150m as shown on the drawings but the bricks may be 100 thick minimum, wall thickness for hollow blocks shall be at least 30mm. If locally made masonry units are to be used then existing buildings using these should be examined to determine their weathering properties, resistances to cracking and structural integrity.
Any blocks showing excessive cracking or weakness shall be discarded and removed from the site.
A cement mortar shall be used for laying the blocks. Cement shall be standard Portland cement as used for the Concrete manufacture. Sand shall be well graded, clean, and free from silt, salt, and organic matter.
A plasticiser admixture may be added to improve the workability of the mortar, at a rate not exceeding 5% by weight of cement.
Lime shall not be used.
Mixes shall be volume batched and shall be 1 part cement to 4 parts sand by volume.
All materials shall be thoroughly mixed to an even consistency for a minimum time of 5 minutes in a mechanical batch mixer.
The minimum compression strength required for the mortar is 8Mpa.
Cylinder test samples are to be made of the first batch when testing facilities are available.
Blocks are to be laid in a stretcher bond pattern with alternate vertical joints in line. When cutting of blocks is necessary it shall be done neatly by saw or chisel true to the shape required.
Pointing of exposed joints shall be done as the work proceeds to form a circular curved recess 3mm deep.
This work shall be done only by experienced block layers, in a workmanlike manner.
The internal walls of all buildings shall be plastered to the top of the lintel beams and down to form a cove at floor level. The floors are not to be plastered. Wall plaster is to be a nominal 20mm thick.
The internal walls of the Meat Market shall generally be plastered to a height of 2m. The wall under the counter shall be plastered full height as shall the low partition wall.
2.7.2 TIME OF PLASTERING
Plastering shall not be done until at least 2 weeks after the columns and masonry infill panels are complete to allow initial shrinkage to take place.
The sand is to be clean and sharp to produce a smooth easily cleaned surface finish. The Portland cement shall be fresh from new bags. Gypsum plaster, lime, or waterproofing additives are to be added strictly in accordance with the manufacturer's recommendations.
Surfaces to be plastered shall be in a proper condition for satisfactory results. Any irregularities which would prevent a full plaster thickness being reached are to be rectified before work begins. Any boxing wires are to be cut off and punched in. Smooth surfaces shall be treated with a special bonding slurry coat.
All work is to be done in accordance with the best trade practices. Any work subsequently found to be ‘drummy’ shall be neatly broken out and made good. The work is if necessary to be screened from a drying wind.
The work is to be finished true and even and free from blemishes. The maximum acceptable departure from a true line shall be 3mm over 1m either horizontal or vertical.
Plaster shall be applied in three coats, a rendering coat, flanking coat and finishing coat.
Plaster coats are to be cured by constant light water spray for a minimum of 7 days. Special attention must be paid that premature drying out does not occur.
This section covers the installation of hot and cold water services, steam supply and the pig scald tank, and underground drainage.
As well as the requirements of this section all work shall comply with any construction requirements laid down by government or local authorities.
The following materials may be used for the various services. Where any of these materials are not in general use in a given location other equivalent materials may be substituted.
Cold Water :
Medium Galvanised pipe to BS 1387 and galvanised malleable iron fittings to BS 143 and 1256.
Polypropylene pipe to Canadian Standard CSA B 137.8–M1977 with matching fittings.
PVC pipe and fittings to BS 3505
As above except that PVC is not permitted for hot water services.
Black medium pipe to BS 1387 and black malleable iron fittings to BS 143 and 1256.
PVC to BS 4581 Vitrified clay pipe to BS 65.
Bronze globe valves shall be used for steam, water valves may be brass, plastic or cast iron diaphragm type depending on availability.
Drainage piping shall be laid in accordance with manufacturer's instructions. Where piping is closer than 300 to the surface pipe shall either be encased in concrete or concrete slabs placed over the pipe to distribute any loads applied. As an alternative to piping open drains may be used outside the building. These shall be constructed in concrete with the invert formed using half round vitrified pipe or alternatively the invert may be formed from cement plaster. The sides shall also be plastered with cement plaster. Where ground levels permit the use of open drains constructed in this manner is recommended. Form the building sumps and screening sump as detailed on the drawings and fabricate and install screen as shown.
Water and Steam
Galvanised and black steel pipework shall be screwed to BS 21. All joints shall be made using PTFE tape as sealant.
Polybutylene pipe shall be installed using purpose made acetal fittings of either the screw or crimp type (crimp type fittings shall only be used if an appropriate crimping tool is available).
P.V.C. piping and fittings for cold water shall be joined by solvent welding.
All pipework shall be installed in accordance with good trade practice. Water and steam piping shall be surface mounted on pipe clamps and shall stand 50 clear of walls to allow cleaning behind. The use of saddles to fix piping directly to walls is not permitted. Steam pipes and hot water pipes shall generally be run 2.4m above floor level to avoid accidental contact. The steam pipe should rise directly from the boiler and then fall continuously to the pig scald tank.
All piping shall, on completion of installation, be subject to a pressure test of 7 bar or 11/2 times the mains water pressure. While under pressure the pipework shall be carefully tested for leaks. Where a suitable test pump is not available pipework may be tested at normal working pressure and inspected as above.
This section covers the supply and commissioning of a packaged chiller unit including an internal meat rail system.
The unit shall be complete with a packaged refrigeration plant generally mounted as shown together with meat rails and their supporting structure supplied loose for installation on site. The concrete floor and foundation slab will be poured on site.
2.9.2 ROOM CONSTRUCTION
The building shall be constructed from insulated sandwich panels using either polystyrene or polyurethane insulation.
Minimum panel thicknesses shall be 100mm (polystyrene) or 75mm (polyurethane). Sheathing shall be colour coated galvanised steel sheet. Panels shall be jointed using a system of proprietary extrusions or similar. Note that extrusions shall not be used on the top surface of the floor.
The chiller supplier shall be experienced in this class of work and shall demonstrate that the construction system proposed will result in a stable weatherproof building under all conditions.
Materials used shall be new and shall comply with the relevant national specifications in the country of manufacture. Polystyrene shall be of the closed cell type manufactured from virgin bead and shall comply with BS 3837. Minimum density shall be 17 kg/cu.m. Cross breaking strength shall be 0.16 mPa and compressive strength 0.11 MPa. Polyurethane panels shall comply with the requirements of BS 4841.
Refrigeration plant shall be sized for the following duty:
|Product Load :||Chill 150 kg of meat over 24 hours using an air temperature of 0–4°C.|
|Other Loads :||Losses due to fan loads, conduction, and door openings shall be allowed for in design.|
|Ambient Conditions||1||Max. Dry Bulb||35°C|
|Max. Wet Bulb||28°C.|
1 Typical for South Pacific check against localmeteorological records and amend as required in
The refrigeration plant shall be based around standard commercial evaporator and condenser packages and shall comply with the following.
The plant shall be suitable for a coastal 1 subtropical environment.
|Power Supply 2||……… volts|
|Evaporator :||Minimum fin spacing 6mm Electric defrost.|
|Condenser :||Air cooled roof mounted with compressor unit. Max condensing temperature 10°C above ambient.|
|Compressor Unit:||The compressor unit shall be of the semihermetic type 3. Motor protection shall include for reduced voltage on any phase as well as overcurrent protection.|
1 Delete ‘coastal’ if not applicable.
2 Insert appropriate voltages, etc.Wherever possible power supply should be 3phase.
3 Where servicing facilities are availablelocally for open type units the reference tosemihermetic should be amended accordingly.Under these circumstances machines should belimited to those models for which servicing isavailable.
Open types may also be preferred in areas wherepower supply fluctuations are severe.
|Tests :||The unit shall be fully assembled and leak tested in the chiller in the manufacturer's works. It shall then be operated for a period of not less than one week prior to shipment to site.|
2.9.4 MEAT RAILS
Meat rails and their supporting structure shall be fabricated as detailed on Drawing 10 and specified in Section 2.4 and shipped separately for subsequent installation on site after the chiller is placed in position and the floor poured. Ensure that the frames as manufactured can enter through the door.
All steelwork, with the exception of the meat rails shall be hot dip galvanised.
This section sets out requirements for the manufacture and supply of mecahnical equipment required for the abattoir and meat market. The first part of this section covers general construction requirements while the second part specifies those items of equipment not covered by detailed drawings. Where detailed construction drawings have been provided for equipment similar proprietary items may be substituted. A full list of equipment is presented in Section 2.12.
The supplier will be responsible for ensuring the compatability of any substituted items with the balance of the plant.
2.10.2 GENERAL CONSTRUCTION REQUIREMENTS
All equipment shall be capable of being readily cleaned and shall be generally constructed as described below.
Table tops and the like should be constructed of grade 304 stainless steel.
Support frames shall generally be mild steel, hot dip galvanised.
Meat rails shall not be galvanised, rather these are to be wire brushed to remove any rust and loose scale and then oiled with an edible oil.
Wood is not permitted for bench tops and the like but may be used for chopping blocks in the meat market and cutting rooms.
The pig scald tank shall not be galvanised.
All mild steel used shall comply with the requirements of BS 4360 : 1972, Grade 43A for structural sections and plate, grade 43C for rectangular hollow sections.
Pipe shall comply with BS 1387.
Welding procedures and welding materials shall meet the requirements laid down in Section 2.4 Steelwork.
Stainless steel shall be welded using the Tungsten Inert Gas method only.
All surfaces to be hot dip galvanised shall have all sharp corners and weld splatter removed by grinding. Surfaces shall then be cleaned by sandblasting or acid pickling and galvanised in accordance with the requirements of BS 729 “Hot Dip Galvanised Coating on Iron and Steel Articles”. Welding after galvanising shall be avoided as far as possible. Where necessary wire brush all welds and make good the galvanising using a zinc based eutectic repair compound.
2.10.6 BLEEDING HOIST (Small Stock) - Item 1.1
Provide one only three part rope hoist and pulleys complete with mounting bracket as detailed on Drawing 17. Rope shall be a synthetic type with limited stretch and have a minimum breaking strength of 350kg.
2.10.7 BLEEDING HOIST (Cattle) - Item 1.2 AND SPREADER HOIST - Item 4.4
These hoists are to be identical and consist of a fine pan rope hoist and pulley complete with mounting bracket as detailed. Rope shall be a synthetic type with limited stretch and have a minimum breaking strength of 1000kg.
2.10.8 ELECTRIC HOIST - Item 4.5
Where a comparatively large number of cattle are being slaughtered an electric hoist should be considered instead of the rope hoists described above. This should be mounted on a trolley running on a hoist beam fixed to the lifting beams. This allows the same hoist to be used for both bleeding and evisceration and would replace items 1.2 and 4.4.
This hoist shall be a chain type with 4m fall complete with trolley and a 4.2m long steel beam to suit the trolley. The beam is to be mounted under and supported off the lifting beam at each end and adjacent to each truss.
2.10.9 VISCERA BUGGY - Item 4.7
Supply one only beef gut buggy of standard design. Body to be galvanised mild steel (or optionally stainless steel) with stainless steel pluck pan.
2.10.10 WASH BASINS - Item 5.1
Wash basins shall be located as shown. Basins are to be complete with galvanised iron frame and backsplash and fitted with foot operated hot (where piped hot water available) and cold water valves. (Koch 1929 or similar).
2.10.11 BOILER - Item 6.1
The boiler shown on Drawing 15 is designed to be constructed of locally available materials and is based on using a used oil drum as the main vessel.
The high level open vent pipe is an integral part of this design and must not be blocked off or have any type of valve fitted to it.
In countries with regulations governing construction and/or use of boilers it must be verified if this design comes under those regulations. In this case it may be necessary to substitute a standard commercial boiler or steam generator for the design shown. This will also be necessary where solid fuel is not available. Under these circumstances a capacity of 60kw would be suitable.
2.10.12 WATER STORAGE TANK - Item 6.3
Water storage tanks shall be either
sectional steel tanks (circular or square) vitreous enamel coated or
Wood stave tanks with food grade PVC liner.
Note that these types have been selected to minimise shipping volume.
Other materials may be used for tank construction provided there is a history of local use over a period of at least eight years.
Square sectional steel tanks, shall comply with BS1564 Specification for Pressed Steel Rectangular Tanks and the vitreous enamel coating with BS1344. “Methods of Testing Vitreous Enamel Finishes” (applicable parts only).
Wood stave tanks shall comply with NZS3603, “Code of Practice for Timber Design”.
Tank capacity will need to be specified separately in each case. A capacity of 40 cu metres is suggested as a minimum.
2.10.13 WATER PUMP - Item 6.4
Whenever possible if a water tank is required, an electric water pump should be installed. The pump shall be a packaged centrifugal pump unit complete with single phase motor, pressure tank, pressure switch and associated fittings. Capacity shall be a minimum of 60 litres per minute at 150kPa.
2.10.14 MEAT RAILS
Meat rails and supports shall be fabricated and installed as shown on the drawings. Ensure tops of all rails are smooth with no sign of laminations, relieve top corners by grinding.
2.10.15 MEAT RAIL ACCESSORIES - Item 10.1 - 10.5
Skids, hooks and ganbrels shall be made from stainless steel by a manufacturer experienced in this work. Bleeding chains shall be constructed with high tensite steel chain; 6mm for cattle and 4mm for pigs and small stock. Refer to Section 2.12 “Equipment List” for list of individual items required.
2.10.16 HIDE HORSE
A wooden hide horse as shown in drawing 18 shall be provided. Materials of construction may be varied to suit locally available materials. Where goat skins only are processed a table can replace the hide horse.
2.10.17 SUSPENSION DRYING FRAMES
These are to be constructed from locally obtainable materials. The preferred material is bamboo, joined by lashing, to give a strong light frame as shown in Drawing 18. Where bamboo is not obtainable small diameter timber poles or sawn timber may be substituted.
This section covers the supply and installation of all electrical services. Note that all equipment shown on drawing 16 Electrical Services may not necessarily be installed in each case, refer to details of each particular contract.
The electrical installation shall be carried out by skilled tradesmen with experience of this trade. The work shall comply with the sizteenth edition of the IEE Wiring Regulations where applicable or with the requirements of the Local Electrical Supply Authority.
2.11.3 SWITCHBOARDS AND INCOMING SUPPLY
Provide a composition panel type main switchboard complete with main switch fuse, sub-circuit fuses and meters. Where a multiple earthed neutral system is employed provide in series with the main switch a 60 amp earth leakage circuit breaker.
The main switchboard is to be mounted in a weatherproof box on the outside wall of the slaughter building in a convenient location with respect to the incoming supply. (If the office/amenities building is constructed it could alternatively be placed in this building).
Provide connection to this main switchboard from the Supply Authority distribution system with neutral screened copper cable buried to a depth of not less than 600mm. (For overhead supply follow local practice). Size this cable to give a voltage drop between the Supply Authorities system and the main switchboard at full connected load, not greater than 2.5% of nominal supply voltage.
2.11.4 WIRING MATERIALS
Sub-circuit wiring shall be either PVC insulated conduit wire protected by high impact PVC conduit or Neutral Screened copper cable or TPS cable fully protected by PVC conduit or similar where exposed below 2.4 metres above floor level.
Where motors are to be connected, screened neutral cable or CBS flexible cable, only are to be used. Cables and conduits are to be secured using PVC saddles spaced at not more than 40 times the outside diameter of the cable or conduit.
Where the Electrical Supply Authority has not set specific cable ratings the following are the maximum ratings to be used:-
|Cable Size||Single Phase||Three Phase|
|1.0 mm||8 amps||5 amps|
|1.5 mm||10 amps||8 amps|
|2.5 mm||15 amps||12 amps|
|4.0 mm||20 amps||15 amps|
2.11.5 ANCILLARY FITTINGS
Light switches and motor isolators are to be rated at not less than the current rating of the load controlled and are to be surface mounted in IP65 enclosures.
Motor starters are to be located adjacent to the motor, complete with stop/start buttons enclosed in polycarbonate or similar corrosion resistant enclosures to IP65: All motors must have an isolating switch located within 2 metres of the motor.
2.11.6 EARTHING AND BONDING
All exposed metal on electrical appliances is to be bonded together using 2.5 mm Green PVC cable or the earthing conduits in multicore cables to ensure that all equipment is maintained at the same earth potential. Similarly metal pipework, building framing and the like must be bonded together using 2.5 mm insulated copper cable secured to the metal using brass bolts and brass or bronze clamps.
Provide as a minimum adjacent to the main switchboard a main earth consisting of not less than 6 mm long galvanised in copper clad steel rods spaced at 2 metre centres and driven to full depth. Connect these to the main switchboard using 16mm bare copper cable. Alternatively provide an earth mat of 6mm bare copper cable in the form of a square with 10 metre sides, buried not less than 400mm below finished ground surface.
|1.1||1||Equipment||Bleeding Hoist & bracket (small stock)|
|1.2||1||Equipment||Bleeding Hoist & bracket (cattle)|
|1.3||2||Sl. House||Floor rings|
|2.1||1||Sl. House||Pig scald tank|
|2.2||1||Sl. House||Lifting frame for above|
|2.3||1||Sl. House||Pig scraping table|
|3.1||1||Sl. House||Small stock rail|
|3.2||1||Sl. House||Viscera inspection table|
|4.1||1||Sl. House||Cattle dressing cradle|
|4.2||1||Sl. House||Cattle rail|
|4.4||1||Equipment||Spreader hoist (hand)|
|4.5||1||Equipment||Hoist (electric) alternative to 4.4 and 1.2|
|4.6||1||Equipment||Head workup rail|
|5.1||2||Equipment||Wash hand basin|
|6.2||1 set||Slaughter||Piping to boiler|
|6.3||1||Slaughter||Water storage tank|
|7.1||1||Cutting & Processing||Rail - cutting & processing room|
|7.2||1||Cutting & Processing||Table - cutting & processing room|
|7.3||1||Equipment||Chopping block (local supply)|
|8.1||1||Tripery||Rail – tripery|
|8.2||1||Tripery||Wash trough – tripery|
|9.2||*||Equipment||Hide drying frames|
|10.1||2||Equipment||Cattle bleeding shackle and chain (Robertson B7900 or similar)|
|10.2||6||Equipment||Small stock bleeding shackle and chain (as Robertson B7900 but 4mm chain)|
|10.3||*||Equipment||Small stock skids and looks (Robertson M0013 plus M5000) (also used for beef quarters)|
|10.4||*||Equipment||Goat gambrels - batchelor type (Robertson M3010)|
|10.5||*||Equipment||Pig gambrels (Robertson P4200)|
* Numbers required to be determined in line with expectedkilling patterns.