1102 Spec Preambles - B Master Rev 2 091205

SECTION B – TRADE PREAMBLES 1.0

MATERIALS AND WORKMANSHIP CLAUSES Generally These materials and workmanship clauses are applicable to, and are to be read in conjunction with and shall be deemed to form part of the description of relevant items in the Schedules of Work included within the Contract documents. The Tenderer is to include in his rates or against the item concerned in this section for the requirements of these Preamble clauses. The whole of the materials for the works (unless otherwise specified) are to be new and of the best quality and manufacture and where not otherwise described to be in accordance with the current British Standard for any specific article or thing where such exists; otherwise they are to be an approved standard consistent with the performance required. The workmanship is to be of the very best description throughout and both materials and workmanship are to be to the satisfaction of the Contract Administrator. Where approval of materials or good is specified, samples are to be submitted; orders are not to be confirmed until approval has been obtained. Approved samples to remain on site for comparison with goods used in the works and remove when no longer required. Where samples of finished work are required obtain approval before proceeding with the Works. Approved samples to remain on site for comparison with the Works and remove when no longer required. Where the manufacturer and reference are used, manufacturer means the firm under whose name the particular product is marketed and reference means the proprietary brand name and/or reference by which the particular product is identified. Where materials or goods are specified to comply with a British Standard or to be manufactured by a particular firm then they are to be used and fixed in accordance with the recommendations of the British Standard or the printed instructions of the manufacturer. Where the term “or other approved” is used in the test, it shall mean that commodities of different manufacture may be substituted if prior approval has been obtained. The maximum rates or prices will be held to be based on the commodities specified. If any alternative commodities are used which are less expensive than those specified then the saving shall be passed on to the Employer. All workmanship shall comply with BS 8000. Dimensions Figured dimensions shall be followed in preference to dimensions scaled from the drawing, but whenever possible, dimensions shall be taken from the building. Before any work is commenced by sub-contractors or orders placed

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with suppliers, dimensions shall be checked on site and agreed with a specialist irrespective of the comparable dimensions shown on the drawings. The Contractor shall be responsible for the accuracy of these dimensions.

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2.0

DEMOLITION/STRIPPING OUT Generally The Contractor shall include in his prices for all necessary scaffolding and for all shoring, needling and strutting or other supports to walls, floors, roofs, etc that may be necessary for the protection and safety of the existing buildings while carrying out the works, all fans, screens and other protection necessary to protect the occupants, workmen and general public and for all alterations, adaptations, maintenance to such temporary works as may be necessary from time to time and finally clear away and make good all work disturbed. The Contractor will be held solely responsible for all temporary arrangements for dealing with rainwater and for the safety of existing buildings and the sufficiency of all temporary work and shall execute all necessary cutting away for fixing needles, shores, etc and after removal shall make good all work disturbed. Any damage resulting form the insufficient precautions being taken will be required to be made good at the Contractor’s own expense. Salvageable Materials All materials form demolitions and alterations will become the property of the Contractor who must allow for any credits and carting away. The Contract Administrator reserves the right to retain any salvageable material. Site Fires The burning of materials on or adjacent to the site is forbidden. Disposal All materials, rubbish and debris are to be carted directly from the building and yard areas and not deposited or left on roads or paths. Any damage caused by breach of this requirement shall be made good at the Contractor’s expense. Asbestos Report immediately to the Contract Administrator any suspected asbestos based materials discovered during the work; avoid disturbing such materials. Agree with the Contract Administrator methods for safe removal. Re-use of Materials Where old materials are described as “stored for re-use” the Contractor shall take all risk of damage in removal and re-fixing and shall replace any damaged or defective work or missing parts at his own expense. Avoidance of Nuisance Pulling down is to be carried out in such a manner as to cause as little inconvenience as possible to adjoining owners or the public and the Contactor will be responsible for any claims that may arise from the disregard of this clause. The rubbish is to be sprinkled with water to prevent dust arising and all proper screens and protection proved to the satisfaction of the Contract Administrator

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Damage to Property Pulling down is to be carried out without damage to the remaining parts of the structure or adjoining property and if such damage shall occur in the carrying out if the demolition, the Contractor shall reinstate and make good such damage at his own expense. All making good is to be executed with materials and workmanship to match in every respect the surrounding work and is to be properly bonded thereto. The Contractor is to provide all temporary shoring, strutting, etc to walls, floors and roofs, necessary for the protection and safety of adjacent and adjoining buildings. Prices for taking out or taking down etc are to include the removing all plugs, fixings, etc and for making good all work disturbed. General Materials and workmanship shall comply with the relevant Trade Preambles. Protection Allow for covering up and protecting as necessary all parts of the existing buildings not directly affected by the work, to prevent damage thereto. The Contractor will be held liable for and must reinstate at his own expense to the satisfaction of the Contract Administrator any damage so caused. Scaffolding Scaffolding and all associated equipment shall comply in all respects with BS 5973, 1981. (Superseding CP 97 Parts 1 and 3) Code of Practice for “Accessing and Working Scaffolds and Special Scaffold Structures in Steel”. In addition, the scaffolding is to comply in all respects with all current Acts of Parliament Statutory Regulations, Bylaws and other Statutory requirements, etc its performance, use, inspection, testing and maintenance should also be in accordance with the appropriate regulations. The external scaffolding to the church is to be protected at the base with a min of 3000mm high vertical protection to prevent unauthorised climbing, in strict accordance with the Ecclesiastical Insurance Groups recommendations, all low level ladders are to be removed from site at the end of each working day. The internal scaffolding is to be of long span nature as the interior of the church is to be in use during the contract period, the scaffold is to be used for the repair of the plastered ceiling and for the redecoration works, a suitable scheme is to be submitted for approval by the contract administrator and the PCC prior to erection taking place.

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3.0

ROOFING Natural slating To be read with Preliminaries/General Conditions. Type(s) of slating Roof slating Base: Rafters at 400mm centres. Pitch: nom 25 to match existing roof. Underlay: Kingspan Nilvent breathable membrane. Lay directly over counter battens. Minimum horizontal lap: 100mm. Battens: 50 x 38mm, counter battens 50 x 38mm. Fixings: Use 100 x 3.35mm galvanised roundhead nails. Slates: To BS 680: Part 2 Type: Second-hand grey stone slate to match existing. Grade: As existing. Size: As existing. Fixing: 1 or 2 No aluminium slate pegs nom 50mm long. Minimum headlamp: 100mm; side lamp 200mm. Slates to be sound, clean, free from edge defects, lamination and cracks and reholed if necessary. Slates of equal thickness to be laid in any one course. Slating generally Basic workmanship: Comply with BS 5534 and BS8000 Part 6. Keep slates clean and dry until laid. Set out to give true lines and regular appearance, fitting neatly at all edges, junctions and features. Fix slate roofing to make the whole sound and weathertight at the earliest opportunity. Repair any defects as quickly as practicable to minimise damage and nuisance. Keep gutters and pipes free of debris and clean out at completion. Underlay Handle carefully to prevent tears and punctures, repair any that do occur

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with adhesive tape and cover with underlay patch tucked under the horizontal lap above. Lay parallel to eaves, maintaining consistent tautness to minimise gaps. Vertical laps must be not less than 100mm wide, coinciding with supports. Fix with galvanised steel, copper or aluminium extra large head felt nails. Where pipes and other components penetrate the underlay, use proprietary underlay seals or cut accurately and turn flanges up to give a tight, water shedding fit. Ensure that underlay does not obstruct roof ventilation. Battens and counter battens Sawn softwood, species type A or B to BS 5534: Part 1, clause 2.12.1. Permissible characteristics and defects must not exceed the limits given in BS 5534: Part 1, Annex E. Moisture contents: Not more than 22% at time of fixing Preservative treatment: CCA vacuum pressure or organic solvent double vacuum as section Z12 and British Wood Preserving and Damp-proofing Association Commodity Specification C8. Batten fixing: In straight horizontal lines, aligned on adjacent areas, with no batten less than 1200mm long. Joints to be square cut, butted centrally on supports and must not occur more than once in any group of four battens on any one support. Provide an additional batten where an unsupported lap in the underlay occur between battens. Fix each batten to reach each support, with splay fixing at joints. Slate fixing: Lay with an even overall appearance, with slightly open butt joints and tails of slates aligned. Use slates of consistent thickness in any one course laid with thicker end as tail. Use extra wide slates generally at ends of courses to maintain bond and ensure that cut slates are as large as possible. Do not use slates or cut slates less than 150mm wide. Centre fix each slate with aluminium slate pegs nom 50mm long.

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Roof slating edges/junctions/features Generally: Form details using the specified fittings and accessories; do not improvise without approval. Cut slates only where necessary, with an appropriate tool, to give neat, close fitting joints and straight, clean edges. Fix edge slates and fittings securely to neat, true lines. Ensure that all flashings (specified in another section) are fixed with or immediately after the slating and are neatly dressed down. Eaves: Underlay support: at Eaves Klober underlay support tray, continuous to prevent water-retaining troughs. Gutter: Dress underlay and underlay support tray into gutter. Undercourse at first course slates: Fix with tails projecting min. 40mm over gutter. Insulation: Where specified insulation to be Kingspan K7 insulation board installed in accordance with the manufacturer’s instructions. Kingspan Insulation Ltd., Pembridge, Leominster, Herefordshire, HR6 9LA Side abutment: Turn underlay not less than 100mm up abutment. Cut slates as necessary and interleave with lead soakers. Fix soakers by turning down over the head of each slate. Fix slates close to abutment to enable a weathertight junction to be formed by metal step flashing (specified in another section). Top edge abutment: Turn underlay not less that 100mm abutment. Finish slating with head-nailed short course to maintain headlap. Fix slates close to abutment to enable a weathertight junction to be formed by metal apron flashing (specified in another section).

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Mortar bedded stone ridge: Lay top course of underlay from one side of ridge over apex to overlap top course of underlay at other side by not less than 150mm. Finish slating with head-nailed short course to maintain headlap. Ridge tiles: As existing – natural stone ridges. Make weathertight with edges continuously bedded and joints solidly bedded in mortar. Where rigid masonry wall support or abut ridge, all ridge tiles within 900 mm of such walls must be mechanically secured. Fix to supplementary ridge Tile-fixing batten with nails/wire ties or screws recommended by tile manufacturer. Fill ends of ridges at gables with mortar and slips of tile-finished flush.

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4.0

LEAD SHEET COVERINGS/FLASHINGS To be read with Preliminaries/General conditions. TYPE (S) OF LEADWORK Apron flashings Lead: Code 5 in lengths not exceeding 1500mm. End to end joints: laps of not less than 100mm. Upstand: Not less than 75mm. Cover to abutment: Not less than 75mm. Fixing: Wedges fixed at 450mm centres. Cover flashings Lead: Code 5 in lengths not exceeding 1500mm. End to end joints: laps of not less than 100mm. Cover: Overlap to upstand of not less than 75mm. Fixing: Wedges Soakers and step flashings Soakers: Lead: Code 4 cut and dressed to shape for fixing by roofer. Length: Slate/tile gauge + lap + 25mm. Upstand: Not less than 75mm. Underlap: Not less than 100mm. Step flashings: Lead: Code 5 in lengths not exceeding 1500mm. End to end joints: Laps of not less than 100mm. Cover: Overlaps to soaker upstands of not less than 65mm. Fixing: Lead wedges at every course. Lead slates: Lead: Code 5 cut and dressed to shape for fixing by roofer. Dimensions: Base: Not less than 400 x 400mm. Upstand: Not less than 150mm, to fit pipe and at angle to suit roof pitch. GENERAL REQUIREMENT/PREPARATORY WORK Workmanship generally Cut, joint and dress lead neatly and accurately, to provide fully waterproof coverings/flashings, free from ripples, kinks, buckling and cracks.

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Comply with BS 6915 and current good practice as described in the latest editions of ‘The Lead Sheet Manual’ published by the Lead Sheet Association, unless specified or agreed otherwise. Do not use scribers or other sharp instruments to mark out lead. Use solder only where specified. Ensure that finished leadwork is fully supported, adequately fixed to resist wind uplift but also able to accommodate thermal movement without distortion or stress. In-situ lead welding: Will be permitted. Hot Works permits are to be completed prior to any insitu lead welding taking place in strict accordance with the Ecclesiastical Insurance Groups requirements. Layout: Agree setting out of joints, drips, and laps with the Contract Administrator before beginning work. Lead sheet: Colour marked for thickness and weight and of the type and code specified: Milled, to BS 1178. Replacement of existing lead: Must be carried out in small sections at a time to reduce the risk of weather damage to a minimum. Provide and maintain temporary waterproof coverings to ensure that there is no damage to the existing base and building. Suitability of bases: Bases to be dry and free of dust, debris, grease and other deleterious matter. Laying of lead will be taken as joint acceptance by the Main Contractor and Sub-Contractor of the suitability of bases. Preparation of existing timber bases: Inform Contract Administrator of any defective boards and comply with instructions for replacement. Ensure that all boards are securely fixed. Punch in any protruding fastenings and plane or sand as necessary to achieve an even surface. Timber for use with leadwork: Planed, free from wane, pitch pockets, decay and insect attack except pinhole borers. Moisture content: Not more than 22% at time of covering. Preservative treatment: CCA as section Z12 and British Wood Preserving Association Commodity Specification C8.

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Fixing/jointing lead Fixings: Where not specified otherwise, fix lead sheet to timber substrates with: Copper clout nails to BS 1202: Part 2, table 2, with annular ring, helical ring or serrated shank, length not less than 20mm, shank diameter not less than 3.35mm and head diameter not less than 8mm, or stainless steel (austenitic) clout nails with annular ring, helical ring or serrated shank, length not less than 19mm, shank diameter not less than 2.65mm and head diameter not less than 8mm. Where not specified otherwise, fix lead sheet to concrete or masonry substrates with: Brass or stainless steel screws to BS 2010, table 3, length not less than 19mm and diameter not less than 3.34mm, with washers of the same material and plastic plugs of length and diameter to suit screws. Clips: Generally 50mm wide where not specified to be continuous, length to suite detail. Lead clips to be cut from sheets of same code as sheet being secured. Copper clips to be cut from 0.6mm thick sheet to BS 2870, temper grade 1/4H, dipped in solder if exposed to view. Unless specified otherwise fix each clip with two fastenings not more than 50mm from edge of lead sheet. Clips welted around edges of sheets to be turned over 25mm. Wedge fixing into joints/chases: Carefully rake out joint/chase to a depth of not less than 25mm. Dress lead into joint/chase and fix with lead wedges at not more than 450mm centres, at every change of direction and with at least two for each piece of lead. Prepare joint/chase and apply sealant. Sealant: Arbosil XL 1099 silicone sealant as manufactured by Adshead of Ratcliffe. Finishing: As soon as practical, apply a smear coating of patination oil evenly in one direction and in dry conditions.

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5.0

STONEWORK Cement Cement to be ordinary Portland cement complying with BS EN 197-1 CEM1. Sand Sand to be approved clean river or pit sand of coarse particles free from organic matter and to be washed if necessary. The proportions specified hereafter are for dry sand. If wet sand is used allowance must be made for increase in bulk. Sand to be Harris sand and Waddington fell sand. Lime Hydraulic lime must be either ground quick lime or hydraulic lime complying with the requirements of Clause 801 of CP 121.101BS Code of Practice for Brickwork. Non-hydraulic or semi-hydraulic lime shall comply with BS890. Water Is to be clean and pure from an approved source and free from deleterious matter. Mortar All mortars shall be mixed with clean water to a proper consistency in a clean mechanical mixer in quantities only required for immediate use. Cement Mortar Shall be one part cement to five parts sand (dry). Gauged mortar Stonework: one part lime and three parts sand (dry). Stonework All sizes are approximate. Before ordering any new stone the Contractor must measure the sizes and profiles on site and prepare all necessary templates and the like. All mouldings, etc are to match the existing undamaged profiles. All dowels, rods, pins, cramps and the like are to be stainless steel grade 316. Stainless steel fixings are to be secured into purpose formed pockets in masonry with a two-part epoxy resin. All adjacent masonry must be fully protected during application of resin and insertion of stainless steel components.

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Epoxy resins and grouts shall be suitable for each different situation where they are to be used. The Contractor shall submit details including manufacturers literature and samples of resins and grouts for the Contract Administrator’s comments before placing orders. Mortars Sand is to be Harris sand, mixed with Waddington fell sand to ensure a suitable range of grain sizes, matched for colour. The sands to be used will be determined after tests of the mortar mixes. Water is to be clean fresh water from mains supply. Lime is to be hydraulic lime putty from local sources. For bedding, the mix is to be1:3 (lime putty:sand). All mortars are to be mixed using only sufficient water to obtain a workable mix and the mortar mix should be beaten before use to improve workability. The lime putty and sand are to be thoroughly mixed together and the cement added immediately before use. Mortar that has begun to set shall not be knocked up for re-use. The use of anti-freeze compounds to not permitted. Where the use of grout is necessary, this should be of the same mix as used for bedding, the use of neat cement grout is not permitted. Stone for new works and replacement Stone for new work and replacement is to be to the Contract Administrator’s approval. A sample is to be provided by the Contractor, against which the colour of the new stones will be matched, allowing for minor natural variations. The stone must be sound, free of natural shakes, vents or other features that may tend to reduce the life of the stone. All arrisses and corners are to be free of snips or other damage. Joints are to be run the full depth of the stone, although the back of the stone may be left rough. The face of Ashlar work may be left as a sawn surface, but all saw marks must be removed. All mouldings to be rubbed finish. All mouldings are to be reproduced accurately, taking as a pattern the best surviving sections. Templates are to be of a suitable and rigid material. If should not be necessary to carry out more than minimal paring-in after fixing. All mouldings are to have a rubbed finish to match existing. In general all replacement stones should be at least 150mm.

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Stones are to be worked so as to give the same joint widths as existing, except that no joint or bed shall be less than 2mm. Both new and surrounding stones are to be wetted before the new stone is fixed. The stone is to be solidly bedded with mortar, and all joints are to be tamped solid as far as possible. Where the use of grout is necessary to fill the joints, the grout shall be no stronger than the specified mortar. Masonry General requirements Code of Practice: Comply with BS 5390 Stone masonry BRE Digest 420 and the Stone Federation of Great Britain ‘Indigenous Stone Quarries’ and ‘Natural Stone Directory’ subject to any qualifications given below. Natural Stone Generally: Provide specified stone to match approved samples as follows: Obtained from the quarry or source specified. Properly seasoned as recommended by the quarry and brought to the proper condition for use. Similar stones for similar applications seasoned for approximately equal time periods. Free from any defects that could adversely affect the integrity of the stone in use. Free from any defects on the faces visible in the completed work that could mar the appearance of the stonework. Each worked stone marked with natural or quarry bed. Supplied to the Works with all shaping and machining completed at the masonry yard. Ashlar Supply worked stones for ashlar, each stone as follows: Feature stones marked for identification with drawings. Fine rubbed finish for all faces and returns, etc visible in the finished work, unless stated otherwise. Worked truly square from all face lines for the full width and thickness. Provided with joggle joints where required, comprising v-profile sinkings to align on the joint faces of abutting stones.

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Stones for random rubble: Of uniform size (but not shape) supplied with sufficient bonders for one every square metre of finished wall. Stones for quoins etc to be dressed and sample approved. Stones for coursed or uncoursed rubble: Roughly dressed square, no stone over 250mm high and no sneck under 75mm high. Supplied with sufficient bonders for one every square metre of finished wall. Stones for quoins, etc to be dressed. Ancillary materials: Metal fixings: Do not fix iron (coated or otherwise) into or against masonry. Fabricate dowels, cramps, ties, and other metal fixings associated with masonry from: Austenitic stainless steel sheet, strip or plate to BS 1449: Part 2 or bar to BS970: Part 4, or Aluminium bronze or phosphor bronze to appropriate BS. Metal wall ties: BS 1243 fabricated from stainless steel/phosphor bronze/copper. Mastics: pointing mastics are to be either one or two parts polysulphide (BS 5254 and 5215) and silicones (BS 5889). Samples must be approved. Samples: Supply the specifier with sample of the stone as specified not less than 250mm square and 100mm on bed with specified finish on one face and one return. Storing and handling materials: All stone: Stack on a clean, dry free-draining surface. Prevent contact with soil. Protect from freezing. Ashlar: Provide a platform raised above the ground. Stack in a manner that permits identification markings to be easily seen and that permits stones to be used in sequence of identification markings to be easily seen and that permits stones to be used in sequence of fixing. Cover with non-staining tarpaulins and protect from rain and freezing. Handling generally: Provide all stones and cast units (other than those small enough to be manhandled) before every delivery site, with suitable mortices for lifting devices to facilitate hoisting or craneage on to their mortar beds. Workmanship: Sample of built masonry: Unless stated otherwise a 1.0m square panel is to be erected with a 0.5m return corner to display stone and mortar, plus any special features. This is to remain in position throughout the works. Ashlar: Keep stones dry, handle with tackle, crane or other suitable mechanical aids.

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Laying: Lay stones level, plumb, square and true with uniform joints of a consistent thickness. Construct the stonework as follows: Spread only sufficient mortar to bed each stone. Ensure that there are no hard lumps in the mortar that could prevent even bedding. Use temporary metal bedding strips to assist even bedding. Moisten dry faces receiving mortar if necessary. Fill all joints and joggle joints solid. Hollow bedding is not permitted. Fit and grout solid, all dowels and cramps, etc as the work proceeds. Jointing and pointing: construct ashlar with a consistent joint and finish with a flush joint as the work proceeds. Site cutting: Unless a properly equipped temporary masonry yard is set up on the site, limit work to ashlar to minor chases, mortices, etc undertaken by a mason. Backings: Ensure backing walls to masonry align with coursing to minimise cuttings. Do not paint the backs of any stones with bitumen. Checking ashlar masonry: Check the stones delivered to the sire to ensure that: Stones are undamaged. Dimensions are correct. Stones are marked in accordance with the fixing instructions. Stones are worked so that the natural bed is normal to the load. Stones are worked so that joints are at right angles to the pressures exerted on them when built (e.g. no mitres are permitted). Sealants To be as specified in Section C. Suitability of Joints Pre-sealing checks: Joint dimensions: within limits specified for the sealant. Substrate quality: Surfaces regular, undamaged and stable. Joints not fit to receive sealant: Submit proposals for rectification. Preparing Joints Surfaces to which sealant must adhere: Remove temporary coatings, tapes, loosely adhering material, dust, oil, grease, surface water and contaminants that may affect bond. Vulnerable surfaces adjacent to joints: Mask to prevent staining or smearing with primer or sealant. Primer, backing strip, bond breaker: Types recommended by sealant manufacturer.

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Backing strip and/or bond breaker installation: Insert into joint to correct depth, without stretching or twisting, leaving no gaps. Protection: Keep joints clean and protect from damage until sealant is applied. Applying sealants Substrate: Dry (unless recommended otherwise) and unaffected by frost, ice or snow. Environmental conditions: Mix and apply primers and sealants within temperature and humidity ranges recommended by manufacturers. Do not dry or raise temperature of joints by heating. Sealant application: Fill joints completely and neatly, ensuring firm adhesion to substrates. Sealant profiles: Butt and lap joints: slightly concave Fillet joints: flat or slightly convex Protection: Protect finished joints form contamination or damage until sealant has cured. Manufacturer Adshead Ratcliffe Derby Road, Belper, Derbyshire. DE56 1WJ Tel: 01773 826661 Fax: 01773 821215

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6.00

CARPENTRY AND JOINERY All timber shall be of the best quality available with due regard for the purpose for which it is to be used and to the approval of the Contract Administrator. The moisture content at the time of fixing shall not be more than 18% or not less than 15% of the dry weight in heated spaces and not more than 24% in unheated spaces. Softwood for joinery is to be European Redwood to approval. Hardwood for joinery is to be Oak. Unless otherwise required by Building Regulations or NHBC requirements, all timber that is to be pressure impregnated against rot is to be Wykamol double vacuum treatment in accordance with the manufacturers instructions. Preservatives Timber preservative treatment Treatment application Timing: After cutting and machining timber, and before assembling components. Processor: Licensed by manufacturer of specified treatment solution. Certification: For each batch of timber provide a certificate of assurance that treatment has been carried out as specified. Commodity Specifications Standard: Current edition of the British Wood Preserving and Damp-proofing Association (BWPDA) Manual Preservative Treatment Solution strengths/treatment cycles General: Select to achieve specified service life and to suit timber treatability Organic Solvent Preservative Treatment Solution: Manufacturer: Wykomol Group Product reference: Green Range Wykomol plus or equal approved Application: Double vacuum + low pressure impregnation Moisture content of timber at time of treatment: As specified for the timber/component at time of fixing. After treatment, timber to be surface dry before use. Water based Micro emulsion Preservative Treatment Solution: Manufacturer: Wykomol Group Product reference: Wood Treat Paste

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Application: Double vacuum + low pressure impregnation Moisture content of timber at time of treatment: As specified for the timber/component at time of fixing. After treatment, timber to be surface dry before use. Preservation treatments to be compatible with any paint or stain decorative products to be applied and shall not bleed through the decorative finish. Plywood and blockboard shall conform the BS 1455 and BS 3444 respectively. Generally, they shall have MR Bonding and a Grade 1 veneer birch or other approved, suitable for painting without filling or excessive sanding. Exterior quality plywood and blockboard shall have ‘WBP Bonding’. All external joinery (except hardwood for staining) is to be knotted and primed prior to delivery to site. All sizes are to be checked on site. Timber shall be pre-treated as required by the Building Regulations. In addition, the following structural elements shall be pre-treated in accordance with the requirements of the NHBC Handbook. 1.

Lintels in brick or blockwork external walls.

2.

Battens as fixings for claddings.

3.

Any embedded timber.

4.

Flat roofs and pitched roofs with fully supported weatherproofing membrane, truss rafters, joists, battens, firings, noggins, wall plates, struttings and blocking.

5.

Joists with ends built into external solid (non-cavity) walls.

6.

Bargeboards, fascias, soffits where not of WBP plywood or other rot resistant materials.

Structural/Carcassing metal/timber Carpentry/timber framing Graded Softwood for structural use generally Grading standard: To BS 4978 or BS EN 519 or other national equivalent and so marked. Timber of a target thickness less than 100mm and not specified for wet exposure: graded at an average moisture content not exceeding 20% with no reading being in excess of 24% and clearly marked as ‘DRY’ or ‘KD’ (kiln dried). Timber graded undried (green) and specified for installation at higher moisture contents: Clearly marked as ‘WET’ or ‘GRN’.

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Strength class to BS EN 338: C 16. Treatment: Organic solvent impregnation to NBS section Z12 and British Wood Preserving and Damp-proofing Association Commodity Specification C8, Service life: 40 years. Ungraded softwood for internal non-structural use Quality of timber: Free from decay, insect attack (except pinhole borers) and with no knots wider than half the width of the section. Surface finish: Regularised Treatment: Organic solvent impregnation to NBS section Z12 and British Wood Preserving and Damp-proofing Association Commodity Specification C8, Service life: 40 years. Graded Hardwood for (Superstructural use generally) Grading standard: to be BS 5756 and so marked. Strength class to BS EN 338: D Surface finish: (Planed) Treatment: (none required). Plywood for gutter decking and roofing generally: (where plain Edge Boarding has not been specified) Standard: to an approved national standard Thickness: 22mm Appearance class to BS EN 635: 111 Bond quality to BS EN 314-2: Class 3 Finish: Sanded Treatment: WBP Selection and use of timber Timber members damaged, crushed or split beyond the limits permitted by their grading: Do not use. Notches and holes: Position in relation to knots or other defects such that the strength of members will not be reduced. Scarf joints, finger joints and splice plates: Do not use unless by approval of the Contract Administrator. Processing Treated Timber Cutting and machining: as much as possible before treatment Extensively processed timber: Retreat timber sawn lengthways, thicknessed,

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planed, ploughed, etc. Surfaces exposed by minor cutting and drilling: Treat with two flood coats of a solution recommended by main treatment solution manufacturer.

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7.00

PLASTERWORK Sand Sand for plastering shall comply with BS 1198 and shall be approved by the manufacturer of the plaster. Mixing No mix shall be re-tamped once it has begun to set and no batch shall be mixed with another batch. Preparation All surfaces to be plastered shall be thoroughly clean and well wetted before the application of the plaster. When concrete is to be plastered or rendered, remove all traces of mould, oil, dirt, etc by washing down with a suitable detergent, followed by plenty of clean water to remove all traces of detergent. Dubbing Out Where dubbing out is necessary, it shall consist of a succession of thin coats to form a plumb and level surface to receive the finish specified. Each coat must be scratched to form a key and allowed to dry out thoroughly before the application of the following coat. Prices Prices for plastering to concrete are to include for hacking off or otherwise preparing surfaces. Plastering to brickwork includes a small proportion of plastering to concrete lintels, etc. Prices are to include for working behind pipes, etc if required. Allow for the provision of metal lathing over steelwork etc in the areas to be plastered, all plaster stops, beads and expansion joints. Plasters The plaster is to be ‘Carlite’ manufactured by British Gypsum Limited, mixed and applied in accordance with their instructions in the number of coats specified. Plasterboard and Skim Plasterboard shall be Gypsum based to comply with BS 1230 with a surface to receive plaster. Type: Gyproc Duplex boards or Gyproc wallboard. Plasterboard shall be fixed broken bond with 38mm galvanised nails at 150mm centres to softwood joists, bearer or battens or 37mm Gyproc dry wall screws.

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The joints are to be scrimmed with 80mm jute scrim cloth and neat Board Finish plaster. The skim coat shall consist of neat ‘Carlite Board Finish’ plaster. Finish The whole of the plastering shall be trowelled to a smooth hard surface, suitable to receive decoration and left straight, plumb and true, without irregularities. Avoid water brush excessive trowelling and over polishing. Work in Cold Weather When the air temperature is 5°C or less, the portion of the building to be plastered shall be completely enclosed. The air temperature shall be raised to ensure that plastering is satisfactorily carried out and heat maintained until the completion of hydration. Provide and maintain necessary heating appliances, taking care to avoid excessive localised drying out and provide adequate artificial and other ventilation.

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8.0

PAINTING AND DECORATING All paints used on the contract are to be in accordance with the latest British Standard Specification. Paint All paint shall be obtained from: ICI Limited, Paints Division, Slough, Bucks, and shall be from the full colour range. Orders for paint must indicate whether interior or exterior quality is required. All paint is to be used exactly to the makers specification and directions and under no circumstances will the addition of thinners, dryers, or other materials be permitted. Paint supplied which is unsatisfactory or defective must be returned immediately to the manufacturer. The contents of the cans must be thoroughly stirred before use. Emulsion Paint Prepare and seal plastered wall surfaces internally and apply specified coats of emulsion paint. Knotting All patent knotting is to be of the best quality consisting of shellac in methylated spirits only, and free from resin and naphtha. Stopping Hard stopping to be a proprietary stopping to be approved by the manufacturer of the paint. Priming Knotting and priming of timber is to be carried out before delivery of the joinery to site and prices are to include for all touching up of primer on site. Colour All painting to be carried out in colours and tints specified by the Contract Administrator. The Contractor is to allow in his rates for painting in multicolour to walls, ceilings, beams and joinery. Scaffolding The Contractor must include in his rates for all necessary scaffolding, planks, lines, dust sheets, etc for the whole of the work.

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Touching up on Completion The Contractor shall take the necessary precautions for the protection of the work and shall make allowance in the tender for all necessary touching up and making good to damaged and defective places as may be required to leave all work free from defects on completion to the entire satisfaction of the Contract Administrator. Method The work must be carried out cleanly and carefully. All fittings, etc must be carefully covered up with an ample supply of dustsheets. All coats must be applied evenly and the finish to be evenly solid, free from brush marks, patches, flashings, or other defects and to the approval of the Contract Administrator. Ironmongery cover plates should be removed. All waste material and splashes shall be taken up and removed as the work proceeds and when directed. Paint shall be neatly cut into glass and edges. Preparation All surfaces must be thoroughly prepared before painting and between coats. Concrete and brickwork shall be thoroughly brushed with a stiff brush and cleaned down. Iron and steel surfaces to be brushed with a wire brush, heavy scraped with steel scrapers if required, left free of all rust and scale. Woodwork to be cleaned and rubbed down with sandpaper, also between coats. All joinery timber will be delivered to site ready primed. The painter is to stop all nail holes, rub down with sandpaper, touch up primer and then paint as specified. Existing surfaces shall be well rubbed down, scraped or sandpapered to remove all loose material, cleaned down with a suitable detergent, rinsed with clean water and allow to dry out. Plastered surfaces are then to be brought to a true level surface including filling all cracks, small holes, etc with ‘Polyfilla’ or other approved filler and bare and filled patches are then to be primed. Existing woodwork is to be brought to a true and level surface including filling all cracks, nail holes, etc with stopping and all bare and filling patches are then to be primed.

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9.0

CAST IRON RAINWATER GOODS Cast iron pipework for external use Pipes, fittings and accessories: Standard: To BS 460 Manufacturer: to be confirmed Product reference: Rainwater pipes to various diameters Type: single socket pipes with ‘ears’ Nominal sizes: 63, 76 and 101mm Finish as supplied: Prefinished black Accessories: offsets, junctions and heads. Jointing: pack joint with jute yarn and seal with cold caulking compound. Fixing: 25mm diameter hardwood offset bobbin spaces to pipe ears secured with Stainless Steel screws into prefixed plastic anchor plugs. Jointing of pipes Generally: Comply with the following procedures when making pipe joints: a. Ensure pipes are clean internally and undamaged. b. Cut pipes square with sharp tools. c. File/ream cut ends and finish smooth. d. Re-round any deformed ends. e. Ensure pipe ends enter fittings and sockets to full depth of jointing area. f. Assemble pipework in a manner that does not entail making joints in restricted locations. g. Leave external vertical rainwater pipe socketted joints open unless otherwise specified. h. Centralise each metal pipe spigot with three lightly wedged pieces of hardwood or folded lead. i. Painted pipework: Allow 30mm minimum clearance at back. Fixing Gutters Joints: Watertight Allowance for thermal and building movement: Provide clearances recommended by manufacturer and maintain as fixing proceeds. Roofing underlay: Dressed into gutter. Gutter with Bolted Joints General: Apply sealing materials/components, and fit washers/spacers, neatly and accurately and as recommended by manufacturer. Tighten bolts in gutter sole first.

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Rainwater outlets Fixing: Securely, before connecting pipe work. Junctions between outlets and pipework: To accommodate movement in structure and pipe work. Fixing pipe work Pipework: Fix securely at specified centre plumb and/or true to line. Branches and low gradient sections: Fix with uniform and adequate falls to drain efficiently. Externally socketed pipes/fittings: Fix with sockets facing upstream. Additional supports: Provide as necessary to support junctions and changes in direction. Vertical pipes: Provide a load bearing support at least at every storey level. Tighten fixings as work proceeds so that every storey is self-supporting. Wedge joints in unsealed metal pipes to prevent rattling. Expansion joint pipe sockets: Fix rigidly to building. Elsewhere, use brackets/fixings that allow pipes to slide. Jointing pipework/gutters General: Joint using materials, fittings and techniques that will make effective and durable connections. Jointing differing pipework/gutter systems: Use adaptors recommended by manufacturers. Cut ends of pipes/gutters: Clean and square with burrs and swarf removed. Chamfer pipe ends before inserting into ring seal sockets. Jointing or mating surfaces: Clean and where necessary lubricated, immediately before assembly. Junctions: Form using fittings intended for the purpose. Jointing material: Strike off flush and remove surplus. Do not allow to project into bore of pipes, fittings and appliances. Surplus flux, solvent, cement: Remove.

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Access for testing and maintenance General: Install pipework and gutters with adequate clearance to permit testing, cleaning and maintenance. Access fittings and rodding eyes: Position so that they are not obstructed by other pipework, framing, etc. Maintenance Instructions General: At completion, submit printed instructions recommending procedures to be established by the Employer for maintenance of the rainwater installation, including full details of recommended inspection, cleaning and repair procedures. Immediately before handover Construction rubbish, debris, swarf, temporary caps and fine dust which may enter the rainwater system: Remove. Do not sweep or flush dust or debris into the rainwater system. Access covers, rodding eyes, outlet gratings and the like: Secured complete with all fixings. Installation generally Discharge of rainwater: Complete, and without leakage or noise nuisance. Components: Obtain from same manufacturer for each type of pipework / guttering. Allowance for thermal and building movement: Provide and maintain clearance as fixing and jointing proceeds. Gutters Setting out: To true line and even gradient to prevent ponding or back fall. Position high points of gutters as close as practical to the roof and low points not more that 50mm below the roof. Joints: Overlap in direction of fall and seal as specified to make watertight. Roofing underlay: Dressed into gutter.

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Pipework Fixing: Securely at specified centres plumb and/or true to line with additional supports as necessary to support pipe collars, particularly at changes in direction. Cut ends of pipes/gutters: Clean and square with burrs and swarf removed.

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