Subcontractors: What They do and What to Pay

Unless you have all building work professionally project managed, at some point you will have to hire subcontractors. Find out what each trade is responsible for below — and how much you should expect to be paying them. 

Groundworker

• Create entry and clear site
• Lay hardcore base for access, deliveries and storage
• Strip topsoil and store for reuse
• Set out house and set to profiles (this may however be done by a surveyor)
• Mark out lines of dig on the ground
• Excavate foundation trenches, load spoil into tipper lorries for off-site disposal or into dumpers for on-site storage and reuse
• Clean and crumb out the trenches
• Set level pegs for the top of the concrete
• Pour and lay foundation concrete
• Lay foundation blockwork to DPC (damp-proof course) level, put in cranked ventilators, all necessary drainage exit lintels and sleeving for services; this may also be undertaken by the bricklayers
• Level out subsoil within the oversite
• Backfill trenches outside the building
• Fill cavities with lean-mix concrete
• Position ground floor beams
• Lay infill blocks and brush grout
• Lay damp-proof membrane and/or gas membrane
• Position and lay first floor beams and infill and brush grout, unless the bricklayers are doing it
• Excavate service trenches
• Excavate trenches for foul and surface water drainage
• Lay drainage runs on pea shingle and bring upstands into oversite
• Haunch over drains with pea shingle
• Fit proprietary manholes, gullies, etc.
• Connect the foul water drains to the on-site mains sewer run, septic tank or sewage treatment plant, or take sewer run to the boundary for road connection by Highways approved contractor
• Construct soakaways and connect surface water drains
• Backfill all drainage and service trenches
• Carry out specified and agreed hard and soft landscaping, including driveways, pathways and patios

Bricklayer

• Lay blockwork to DPC level including installing ventilators, drainage exit lintels and sleeving, unless the groundworkers undertake this task
• Lay ground floor beams, infill blocks and brush grout, unless the groundworkers undertake this task
• Bed DPC, marrying this to any damp or gas membrane or cavity trays
• Build superstructure in brickwork and blockwork
• Install cavity insulation as work progresses
• Install cavity closers
• Fit timber windows or build in profiles
• Build in meter boxes
• Position and bed lintels, padstones and steel joists
• Lay first floor beams, infill with blocks and brush grout, if the groundworkers don’t undertake this role
• Install cavity trays where necessary
• Bed wallplate
• Build up gable ends
• Build chimney through roof
• Build internal brick features and fireplaces
• Point up flashings and trays
• Fill putlog holes
• Build any feature walls or brickwork in garden as specified and agreed

Carpenter

First fix

• Making up and fixing templates for openings, where appropriate
• Fitting door linings
• Making up studwork partitioning, including to fitted cupboards, where necessary
• Fix underfloor plasterboard battening using proprietary batten clips
• Install insulation to studwork partitioning
• Install insulation within ceiling and floor zones and to roof void
• Fix window boards
• Fix staircase flights
• Make up and fix garage door frames
• Nog out for plasterboard
• Hang temporary external doors, where appropriate
• Board out loft, where appropriate
• Create and fix loft entrance and fit loft ladder

Roof

• Erect and complete roof using prefabricated trusses and lumber, to include gable ladders, valleys, hips and construction of dormers, porches and bay window roofs
• Fit rooflights where required
• Lay sarking boarding where appropriate
• Fix facias and soffits, including ventilators, where necessary
• Fix bargeboards, where appropriate

Second fix

• Box in pipework and vent pipes
• Lay insulation and timber decking to floors, where appropriate and unless carried out by other specialist suppliers
• Assemble and fit staircase newels, balustrading, aprons and handrails, etc.
• Hang all internal doors including cupboard doors and fitted wardrobes
• Fit slatted shelving to linen cupboards
• Final fit of loft traps
• Assemble and fix fitted units to kitchen, utility room, bedrooms and bathrooms, unless carried out by specialist manufacturers or suppliers

Electrician

• Fit temporary consumer unit to building supply
• Install and connect domestic earth rod
• Lay and fix all carcassing wiring
• Fix backplates to outlets and controls
• Fix proprietary sheathing to wiring
• Fix and wire up faceplates, pendants, wall lights and controls
• Fit and wire up external power points and lighting
• Fix and wire up extractor fans and cooker hoods
• Cross bond and earth all pipework and sanitaryware
• Fit and wire up consumer unit
• Wire up thermostats, controls and programmers
• Attend plumber for firing up and testing boiler and central heating, if and when required
• Test installation

Roofer

• Cover roof with underlay and rough batten
• Fix GRP valleys or attend plumber for fixing lead valleys
• Bed and fix undercloak to verges
• Fix counter battens if necessary
• Gauge and fix tiling/slating battens
• Load out tiles or slates
• Lay tiles or slates, nailing as required and appropriate
• Lay valley tiles, if required
• Fix verge slates/tiles
• Interleave upstand and cover flashings and soakers
• Attend plumber for vent pipe skirtings
• Fix or bed ridge/hip tiles or ridge/hip system
• Point up ridge/hip tiles and verges

Plumber

• Install water standpipe for building supply
• Lay first fix carcassing pipework
• Run any gas pipework
• Make up lead flashings, soakers and vent pipe skirts as appropriate
• Fix vent pipes to drainage upstands and take to stub stacks or through roof
• Fix skirts to vent pipes with roofer
• Fix guttering and downpipes
• Position hot water cylinder
• Lay underfloor insulation, taping joints and cover with membrane
• Lay underfloor central heating loops to manifold position
• Connect underfloor heating loops to manifold and put on test, once screed is laid
• Fit the boiler and connect to system
• Attend to chimney flues and liners
• Connect boiler to LPG, oil or mains gas supply
• Fit sanitaryware and connect to domestic plumbing and wastes
• Mastic seal around baths and washbasins
• Plumb in washing machines, water softeners etc., as appropriate
• Lag all exposed or vulnerable pipework
• Fire up boiler and test system
• Balance and commission system
• Switch underfloor heating off ‘test’ and to ‘run’ once test period is over

Plasterer

• Screed floors as soon as underfloor central heating loops are laid, unless left to specialist suppliers and installers using pumped self-levelling material
• Tack ceilings with plasterboard
• Fix all beadings and lathing
• Float and set all masonry walls, or dryline walls with plasterboard
• Fit mouldings and coving
• Tape and joint all boards and skim coat with plaster finish
• Render external walls, where appropriate

Decorator

• Snag and make good all walls prior to decorating
• Fill all holes and gaps
• Apply mastic around all external joinery
• Rub down and fill all joinery
• Knot any timber to be painted
• Prime and undercoat all internal and external joinery or timber to be painted
• Gloss coat or stain internal joinery or timber
• Paint all internal walls and ceilings with mist coat plus two coats of emulsion
• Paint external render with two coats of proprietary finish