trade specification for carpenter€¦ · internal birdcage scaffold/crash deck will be installed...

Trade Specification for Carpenter October 2019 1

TRADE SPECIFICATION FOR CARPENTER

INTRODUCTION This trade specification must be read in conjunction with the Bovis Homes’ Contract Conditions, all drawings, specifications, any planning or environmental requirements and relevant sections of NHBC Standards. 1.0 GENERAL REQUIREMENTS

1.1 As a minimum requirement, all operatives must hold a current CSCS card applicable to their

trade. Supervisors must hold a current CSCS Gold Card or CITB SSSTS certificate. All trades totalling three or more operatives on site must have an on-site trade supervisor (SSSTS or gold card). This person can be a working supervisor.

1.2 Contractors shall provide evidence that their operatives have received suitable training for any plant or equipment they will be operating/using, including proprietary access systems where applicable. All hand-held power tools will either be battery or 110v powered where practicable and must be maintained in good condition with all guarding/safety features in place. Permission must be sought from the Bovis Homes’ where any tools are required with increased voltage. Contractors are required to carry out 3 monthly PAT testing for all electrical tools on site.

1.3 All operatives and supervisors are required to participate in the Bovis Homes Health and Safety Induction and Quality Induction Programme before commencing work on site. This will be given by the Site Manager and a signed record maintained.

1.4 The Contractors Supervisor is required to attend and actively participate in Daily Activity Briefings (DABs) with the Site Manager. Supervisors are required to visually inspect work areas prior to putting operatives to work. Contractors should be made aware of all Standard Operating Procedure’s (SOPS) and must comply with the requirements.

1.5 A Trade Self-Certification Checklist must be completed by the Contractor for every plot and receipt of the same by the Employer is a prerequisite of final payment.

1.6 The Contractor will be required to assist with the completion of the Bovis Production Quality Plot Log for each plot.

1.7 Any inadequate information must be highlighted to the Employer in writing. It will be the Contractor’s responsibility to ensure that sufficient information is available to carry out the works to meet all technical, health and safety and programme requirements.

2.0 FACILITIES PROVIDED BY THE EMPLOYER The following will be provided by the Employer:


2.1 Erected scaffold for access/working platforms and all necessary internal working scaffold

together with fall prevention system (birdcage/crash deck) where applicable. The Contractor will supply suitable equipment to safely allow the fixing of high level bracing to roof trusses.

2.2 Internal birdcage scaffold/crash deck will be installed by others i.e. Scaffolder. They must be installed before any joisting or roof works commence and are to remain in place until the floor is fully complete and/or roof trusses are fully felted and battened. Scaffolding must not be adapted by Contractors other than the approved Scaffolding Contractor. The use of bandstands and trestles is not permitted.

2.3 Stairwell access system provided by Employer. The Contractor is responsible for erection by a suitably trained operative and for the subsequent removal.

2.4 Fork lift truck/driver assistance on a shared use basis with other trades. No claims for standing time will be entertained. Unless otherwise stated at enquiry, Bovis Homes will supply one fork lift and one driver only under the terms of the Contract.

2.5 Crane facility on a contract lift basis.

2.6 Shared welfare facilities as per Bovis Homes’ Policy for Health, Safety and Welfare. All other plant, equipment and tools, including additional approved access equipment, shall be

supplied by the Contractor, e.g. 110-volt or lower power generating plant and fuel, transformers, all power tools, hand tools and consumables, sufficient to meet the requirements of the programme and the progress of the works. All electrical tools are to be PAT tested.

Additionally seasonal hire of task lighting and heating equipment when necessary is the Contractor’s responsibility.

3.0 MATERIALS

All materials are to be supplied by the Employer, except for the following, which will be supplied by the Contractor:

3.1 All fixings, including nails, screws, specialist fixings, sealants and adhesives, (except

adhesive in connection with chipboard flooring). All such fixings etc. shall comply, where applicable, with product manufacturer’s recommendations. Nails for roofing works to be galvanised. All external metalwork and fixings must be non-corrosive.

3.2 Ironmongery – all ironmongery shall be Carlisle Brass and shall be supplied by the Contractor from the regionally nominated ironmongery supplier.

3.3 In the case of materials supplied by the Employer, it is the Contractor’s responsibility to ensure that adequate quantities of such materials are maintained on site. It is incumbent on the Contractor to notify Bovis Homes of low stocks giving sufficient notice to allow such stocks to be replenished/maintained at optimum levels commensurate with the programme of works.


The Contractor is responsible for all loading out as necessary. Wherever possible large materials will be loaded mechanically by Bovis Homes close to the required working area. However no claim will be accepted for any waiting time, sorting or collection of such materials from the site stores. The Contractor will, where necessary, collect materials not being loaded out by Bovis Homes, from the store. The Contractor shall provide an effective Local Exhaust Ventilation (LEV) system for mechanical dust extraction that must be used whenever any form of wood is machined or sanded. Any residual dust should not be brushed up but the LEV system used with appropriate attachments to remove the dust. As a minimum, FFP3 respiratory protection equipment must be worn by operatives which is combined with an organic vapour filter to provide protection against formaldehyde vapours. Evidence needs to be provided of face fit testing to BHL Site Management.

4.0 SCOPE OF WORKS The following section provides an overall description of works to be undertaken by your trade and, as such, highlights extracts of standards, workmanship and practice for your attention, it cannot describe all of the detailed requirements of British Standards, EU Standards, NHBC Standards, manufacturer’s instructions, industry trade best practice and other legislative requirements which will be deemed to apply to your trade. Specific site drawings, standard construction details and the Group General Specification must be read in conjunction with this section.

4.1 FLOORING JOISTS & CHIPBOARD FLOORING 4.1.1 Hoist, level with slate or other approved material and fix all joists in accordance

with manufacturer’s drawings and details. Joists are to be spaced no greater than 400mm centres with a 25mm-75mm max gap between wall and first joist.

4.1.2 Fix all joist hangers and timber connectors as shown on the manufacturer’s

drawings, including bolting together multiple joists/beams where indicated on the drawing.

4.1.3 All joists are to be built into brickwork by Bricklayer. The Contractor is then to

very carefully seal around joists/blockwork as NHBC/Site Detail Manual and Accredited Details with low modulus silicone sealant (provided by the Contractor) to form an effective air seal.

4.1.4 Fix permanent bracing where shown on joist layout drawing. 4.1.5 Carry out final adjustment of position of metal beams (where applicable) and

frame out to receive plasterboard or other finish.

4.1.6 Fix gms lateral restraint straps as manufacturer’s layout drawing. Straps to be

a maximum 2 metres apart and carried over three joists. Straps should bear on the centre of bricks or blocks, not on mortar joints. All chipboard flooring shall be supported in accordance with manufacturer and NHBC requirements.

4.1.7 Temporarily brace joists in accordance with manufacturers’ recommendations.


4.1.8 Fix noggin supports to plasterboard ceiling, as required, in accordance with

manufacturer’s instructions. 4.1.9 All timber which is to be built into brick or blockwork, or to be embedded in

concrete or floor screeds, must be treated with a suitable preservative, supplied by the Contractor and applied in accordance with the manufacturer’s instructions. Where ends of timber are built into external walls, the preservative shall be applied to the surface, a minimum of 150mm beyond the line of the brick or blockwork.

4.1.10 Joists are to be decked with Norboard, Caberdek, Peel Clean 22mm chipboard

flooring, as soon as joists are installed. All work to be in accordance with manufacturer’s instructions and BBA agreement certificate. Tape all joints, nail holes and edges of chipboard flooring with Caberfix tape. Boards are to be glued to joists and joined together with Norboard Caberfix D4 Flooring adhesive and nailed to the Bovis Homes/Caberdek nailing pattern (reference Bovis System), in strict accordance with manufacturer’s recommendations.

Proprietary tape and adhesive system (tongue and bed) to be supplied by the Employer. Form letterbox opening in floor to facilitate the loading out of plasterboard to upper floors and subsequently reinstate floor. Maximum size of opening 100mm x 1400mm.

4.1.11 Should it be necessary to notch a joist over a joist hanger to produce a flat ceiling, the notch must be no more than 5mm deep x 75mm (the length of the hanger), as verified by the manufacturer.

4.1.12 Sacrificial section of floor or TG20 scaffold protection (Boards to be supplied by

the Scaffolder), to be used to prevent fall risk. 4.1.13 Form all works in connection with the timber separating floor construction to

coach houses, (FOGs), including placing of Gyproc plank and installing insulation between joist supported on breather membrane (supplied by others).

4.2 ROOFING

The Contractor is responsible for the erection of trusses and spandrel panels and pre-fabricated GRP dormers (where applicable) utilising mobile cranes. The lifting operation must be carried out on a ‘Contract Lift’ basis only and strictly in accordance with the provisions of Bovis Homes’ Standard Operating Procedure (SOP) Cranes & Lifting Management ref BHL-HSE-SOP-07. The contractor must obtain approval of lifting plans using HS Form 36 prior to the commencement of any lifting operations. The ‘Contract Lift’ can be provided by Bovis homes’ or via the Carpentry Contractor. This will be confirmed in the site tender documents.


4.2.1 Main roof

a) b)

Trusses installed in line with the Trust Rafter Association Roof Trusses October 2017 Version 2 installation guide. Cut wall plates and provide to Bricklayer for bedding. Attend on crane and, in accordance with roof working drawings/ manufacturer’s details, construct roof including trusses, any ‘cut’ timbers including dormer works, bracing, fascia’s, barge boards, ladders, soffits, tank stands, walkways, etc, lay boards, vents, straps and shoes, sprockets, truss clips, roof vents, ply support to GRP valleys, noggins, bolts, connectors and all other work to complete the roof structure. Erect two part roof trusses all as Contractor’s method statement and detail sketch. Spandrel panels shown on roof layouts are to be installed by the Contractor in accordance with manufacturer’s details and standard detail Wa120 including fixing lateral bracing and holding down straps. Temporary bracing/truss erection to recognised standard/design provided by the Trussed Rafter Association. Spandrel party wall panels to be bedded in intumescent mastic. Vertical joints between party wall spandrel sections to be sealed with 150mm wide strips of 15mm thick Fermacell Gyproc Fibreboard fixed with 55mm Fermacell screws as per standard detail Wa120. Gable end panels to be laid on compressible mineral wool seal on top of wall.

c) The Contractor shall allow for installing suitable temporary bracing

to roof trusses/spandrel panels during construction and shall provide details of same in his method statement.

d) Wall plate restraint straps to be plugged and screwed with No. 12 x

50mm wood screws at max 300mm centres into plugs. These should be fully fixed immediately upon safe access to 1st/2nd floors being provided (stairs fitted) and removal of birdcage/crashdeck by Scaffold Contractor. Tie down straps to house and garage wall plates must be fitted in all cases at the time of roof construction provided safe access is available.

e) Plywood layboards 100mm wide are to be provided to either side of

the valley 175mm from the centre of the valley to the centre of the timber support fixed flush with the top of the rafter.

4.2.2 Addendum specification for room in roof house types a) Fix plywood to underside of rafters in accordance with Standard

Detail Ro140.


b) Fix breather paper and ply to sides of trusses in accordance with Standard Detail RO140.

c) Dormers to room in the roof and other three-storey house types will

generally be GRP pre-fabricated construction, fixed to roof structure. The Contractor is responsible for lifting into position (by crane) and fixing the dormer to the roof timbers by drilling and screwing (no nails) through the outer fixing flange. Do not remove or cut any part of the dormer or penetrate any part of the dormer with nails or screws (except the fixing flange) – refer to manufacturer’s detailed installation instructions.

d) Fix any necessary roof lights in accordance with details and

manufacturer’s requirements. e) Fix Kingspan insulation boards to trusses (sloping and vertical) as per

detail. Fix 105mm thick Kingspan Thermapitch TP10 rigid insulation tightly fixed between rafters and tightly butted between sheets. Great care must be taken to ensure tight fit of insulation with no gaps. This should be undertaken from the outside. See Standard Detail Ro140

f) Fix 40mm thick Kingspan Thermapitch TP10 rigid insulation board to

underside of roof trusses and unventilated void area from wall plate to intersection of wall/sloping ceiling junction on top of 105mm board as previously described. Each sheet is to be tightly butted ensuring no gaps exist. Seal all joints of sloping ceiling and vertical with duct tape to ensure air tightness. The sloping section of insulation should extend from wallplate into the loft space a minimum of 300mm (or greater dimension to suit depth of loft insulation) above the level of the underside of the bottom truss chord. See Standard Detail Ro140

g) Seal between last rafter/joist and gable wall with min 150mm deep

100mm Knauf Insulation Loft Roll 44 mineral wool fibre insulation tightly packed.

4.2.3 PVCu fascia’s and soffits

PVCu fascia’s, bargeboards and soffits are to be installed in accordance with the manufacturer’s instructions.

4.2.4 Lower roofs a) Construct all lower roofs including garages, car ports, sub-stations,

bin stores, cycle stores, porches, bays and canopies, in accordance with construction drawings including any cut and pitch elements. This may include fixing GRP porch canopies/bay window roofs. All work to be undertaken from properly erected scaffolding.


b) GRP porch canopies are to be fixed with screws and bedded in mastic against external walls in strict accordance with Manufacturer’s recommendations.

4.3 FIRST FIXING 4.3.1

Assemble and fix factory primed staircase including newels, bullnose treads, risers (all risers to be glued and screwed), nosing’s, aprons and all works to 1st fix staircase in accordance with the BWF Installation Guide: Timber Stairs. Apply Fischer fixings for strings to wall. Immediately erect proprietary stairwell protection and signage supplied by Bovis Homes. Note that balustrades will be delivered pre-assembled and pre-finished separately from main flight with balustrades being installed at 2nd fix stage. Care must be exercised in fixing and protection. Construct as shown on working drawings, half/quarter landings in connection with staircases. Erect timber staircases to common parts of apartment blocks as per sequence document, using crane supplied by Bovis Homes immediately prior to roof truss erection. (See Clause 2.5 also).

4.3.2 Stair winders to be supported on bearers in accordance with the

manufacturer’s recommendations. Frame beneath stair winders/half landings suitable for plasterboard finish in accordance with Standard Detail Ff 015

4.3.3 Cut, position and fix all necessary trimming to form suitable access to roof

space in accordance with standard detail. 4.3.4

4.34 (a)

Fit and secure window boards with 150mm x 75mm x 25mm frame cramps (NOT Owlet ties or similar), including works to bays and lipping’s to bays (where applicable). Timber stud partitions (Phoenix housing range only) – construct timber stud partitions in 63mm CLS with studs generally at maximum 600mm centres in accordance with ‘British Gypsum White Book’ non-loadbearing timber stud (CO4511 and C04.S11) and NHBC Standards Chapter 9. Note: grounds for radiators, kitchen units, sanitaryware, light switches and stair handrails etc fitted by Drylining Contractor. Walls to receive tiling to have studs at maximum 400mm centres

4.3.5 Fix MDF door-kit linings to block work walls, metal stud, or timber frame min

300mm fixing centres. 4.3.6 Construct framework to SVP locations shown on the drawings, pipework

casings and bath panel casings in bathrooms and ensuites. N.B. All exposed pipework is to be cased, which may not be shown on drawings. All boxings constructed must be square and true. (See standard bathroom/en-suite and combined cloaks/utility drawings for more details). Allow to construct shower tray plinth framework in RIR and apartment house types.


4.3.7 Construct framework to gas riser casing where indicated as Standard Detail SV110.

4.3.8 Construct framework to infill panel above and below boiler, see Standard Detail SV113 and 114. Fix frontal matched kitchen panel (supplied by Kitchen Contractor) to boxing above boiler.

4.3.9 Construct studwork diaphragm wall and OSB board skinning where indicated

as Standard Detail Wa 110. 4.3.10 Construct bulkhead and any spandrel walls required including underside stairs. 4.3.11 Pack out around lintels and steels where necessary to prepare for plasterboard. 4.3.12 Fix framing for fire protection of steel beams. 4.3.13 Fix stand for hot water storage cylinder where applicable. 4.3.14 Fix cover fillet to bottom edge of tile cladding detail where applicable. 4.3.15 Fix cover fillet to vertical tiling at gables and stop end return details, where

required. 4.3.16 Fit noggins and boarding in association with services as shown on drawings. 4.4 SECOND FIXING 4.4.1 Construct builder’s wardrobes (where specified) as Standard detail Jo107

including fixing shelving and hanging rail. Fix architraves on inside of wardrobe. 4.4.2 Fix all mouldings including MDF architraves, MDF skirtings, quadrants, beads,

cover fillets, etc. Should hardwood be specified on the Group General Specification then allow for plugging, screwing and pelleting. You should allow to fix skirting to metal stud partitions in non-load bearing walls by gluing and nailing. Allow a return visit to fix skirtings where tiled flooring specified.

4.4.3 Complete works to staircase including handrails, balusters and cappings. N.B.

Balustrades are pre-assembled. 4.4.4 Fix 50mm x 25mm PAR slatted shelving to airing cupboard as Standard Detail

Jo 100. 4.4.5 Frame out and fit access panels in SVP casings previously clad in plasterboard

by others. 4.4.6 Fix preformed drop down loft access hatches in accordance with the

manufacturer’s details to ensure air tightness.


4.4.7 Fix 6mm plywood overlay to bathroom and ensuite floors at right angles to the chipboard flooring using adhesive and 25mm long countersunk screws at 200mm centres in accordance with Porcelanosa instructions.

4.4.8 Frame and clad any down stand steel beams in garage locations including

Supalux (or similar specified) to soffit of exposed garage lintel. 4.4.9 Ensure all duct work is tightly fitted and sealed with expanding foam insulation

to preserve the air tightness of the dwelling. 4.4.10 Allow for cutting cupboard shelf under sink to accommodate plumbers

pipework 4.4.11 Protect all works in this section in accordance with the Bovis Homes’ Site

Protection Policy Rev A, including fitting newel protection to staircases. The Contractor is responsible for replacing any protection removed to carry out their work. Remove and salvage all protection when directed.

4.5 INTERNAL AND EXTERNAL DOORS 4.5.1 External

a) Front/rear entrance/garage personnel doors (where applicable)

Front and rear entrances will be Birtley GRP pre-hung door sets. Make up profiles for Bricklayers, remove prior to drylining, salvage and re-use after completion. Fix door sets complete with door cill. Doors shall be fitted and adjusted strictly in accordance with manufacturer’s recommended installation guide. Ensure adequate support provided to underside of door cill to prevent damage and fully seal with mastic to underside. Apply protection to door immediately following installation. Note: The Contractor shall ensure that the composite door sets are stored in accordance with best practice recommended by Birtley Doors.

b) Garage doors and frame

Assemble profile for building in by Bricklayer, salvage and re-use upon completion. Fix pre-finished up and over metal/timber garage doors. Check tension of doors. Fit any cover moulding necessary between frame and structural opening. Note: Electrically operated garage doors to be fitted by others.

c) PVCu French casement doors/Bi-fold doors


Make up dummy frames for Bricklayer, salvage and re-use after completion. Patio doors to be fixed by External Window/Door Contractor.

d) Keys

All door keys are to be returned clearly labelled with the plot number, to the Site Manager immediately following the fixing of the locks. Failure to comply with this will result in a contra charge being levied against the Contractor if external locks have to be changed.

4.5.2 Internal

Fix MDF door and lining kit and door stop with intumescent strips (where applicable) and MDF architraves. Fit factory primed internal doors. Ironmongery to be fitted at finals stage. Note: Where applicable cut an adapt door blank and lining to suit under stairs cupboard. Frame to door gaps are not to exceed 3mm and must be equal on both sides and at head. At threshold or floor finish 10mm is permitted. The gap under any fire door must not exceed 10mm from a floor finish. Adjustments for carpets/other floor finishes must be accommodated within these tolerances.

4.6 KITCHENS AND PROPRIETARY SLIDING WARDROBES 4.6.1 Kitchen units/worktops shall be supplied and fitted by the specialist Kitchen

Contractor.

4.6.2 Where shown on the drawing sliding wardrobes shall be supplied and fitted by

the specialist Wardrobe Contractor. 4.7 PVCu WINDOWS

All work to PVCu windows to be completed by External Window/Door Contractor.

4.8 FINALS 4.8.1 Final fix wardrobe doors (where specified as builder’s wardrobes). 4.8.2 Fix all ironmongery. 4.8.3 Fix only bath and shower tray panels to manufacturer’s details (supplied by

Plumber) or skirting panel with capped screws over raised shower trays. 4.8.4 Adjust and oil all locks, bolts and keeps.


4.8.5 Fix door stops to all internal doors and proprietary extended stops where required.

4.9 FALSE CHIMNEY CONSTRUCTION AND DOVECOTS Where specified, construct framework for and fix in place as part of roof construction, GRP “dummy” chimney and GRP dovecots where shown, all as Standard Details. To be lifted and placed using crane supplied by the Employer in connection with roof construction works (see Clause 2.5).

4.10 CLADDING/FLYING LINK CEILINGS (UNDERPASS) 4.10.1 Where applicable construct Eternit weatherboarding as indicated on the

External Finishes Schedule and working drawings in accordance with manufacturer’s recommendations and Standard Detail Wa 106 and Wa 128.

4.10.2 Carry out all work to flying link ceilings including insulation and air seal barrier

as indicated in Group General Specification, working drawings and Standard Detail IF 100.

5.0 GENERAL/MISCELLANEOUS ITEMS 5.1 Ensure all plumbing and electrical services are not damaged by your work or fixings. 5.2 Provide roof truss/rafter templates for Bricklayers for building in cavity trays to abutments

etc.

5.3 Allow for fitting communal letter box unit to apartments. 5.4 Assemble garden sheds where applicable. 6.0 PROTECTION OF THE WORKS 6.1 The Contractor shall protect all works in accordance with Bovis Homes’ Site

Materials Protection Policy Rev A. 6.2 The Contractor shall allow for making up temporary plywood protection to baths and

shower trays to be applied immediately following installation of the sanitaryware. 7.0 WASTE MANAGEMENT 7.1 GENERAL


7.1.2 The control of waste is not only a key issue for Bovis Homes but also for all our Contractors. Together we need to minimise waste production and reduce the expense of disposing of any waste materials that we produce.

7.1.3 We would draw your attention to the section on site tidiness contained in the

Contract Conditions, in particular frequency of clearing and cleaning. All work areas are to be left clean and any waste/rubbish placed into mini skips on a daily basis.

7.2 CARPENTRY WORKS 7.2.1 All timber waste and waste arising from Carpentry works, should be deposited

into Yellow mini-skips (timber Waste). Timber should be no longer than 600mm in length. Lengths over 600mm should not be regarded as waste but returned to store for future use.

7.2.2 All plastic, cardboard or paper waste should be deposited into Orange mini

skips (LMW Waste). 7.2.3 In particular we are concerned with the amount of waste created by excess

timber and seek your co-operation in reducing waste levels. 7.2.4 Roof construction should be formed of complete roof packs. Please put aside

any surplus material from roofing works for collection by the supplier. The supplier will also inspect roof construction to determine proper usage of material supplied.

7.2.5 1st and 2nd fix material will be scheduled and ordered per plot and again any

surplus material should be noted, the Site Manager advised, and the material put aside for collection by the supplier.

7.2.6 Mastic tubes, glue tubes, empty preservative tins, etc to be deposited into the

Hazardous Waste skip in the compound. 7.2.7 The Contractor will be contra charged for waste not disposed of in the correct

manner, including consequential costs.

trade specification for carpenter€¦ · internal birdcage scaffold/crash deck will be installed...

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