Structural carpentry
Structural carpentry across Lincolnshire, Cambridgeshire and Norfolk: floor joists, structural floors, timber frame and stud partitions, built to the engineer's design. Send the drawings and the joist design for a priced package.
What this covers
Structural carpentry is everything in a building that carries load and is made of timber: floor joists and structural floors, timber frame walls, load-bearing stud partitions, timber infill to structural steel, trimming to openings, and the roof structure that sits on top of it all. It is designed by an engineer and built to that design, which makes it a different job from trim carpentry, where the target is a finish rather than a calculation.
AJB Group takes structural carpentry as a package on new build, conversion and extension work. The scope typically begins at the joist set and runs through decking, partitions and structural openings to the point where a plot is ready for the roof or for first fix to continue. Where the roof is in the same appointment, the same external team carries straight on into it.
Specification is followed as drawn, not improvised. A typical traditional set is C24 8x2 at 400mm centres with 22mm Caberdex flooring. Posi-joist sets, traditional hand cut sets, squint block sets and hand cut joists with hangers infilled into structural steel are all routine, and where an engineer has specified 18mm marine ply as the deck rather than chipboard, that is what goes down. On extensions, glulam beams are used as ridges and structural members where the span calls for it, for instance a 4.2 metre glulam ridge with ceiling ties on a hand cut extension roof at Long Sutton.
The two work packages inside this silo have their own pages: floor joists and structural floors, and timber frame erection. Both link across to the commercial 1st fix carpentry package, which is where structural carpentry usually sits on a contractor's programme.
The two packages
Most contracts take joists and frame together, but either can be appointed on its own.
Posi-joist, traditional hand cut and squint block sets, hangers, trimming to openings and decking. C24 8x2 at 400mm centres with 22mm Caberdex is the everyday specification, and a 288 square metre set has been completed in two days.
Timber frame walls and extensions erected, squared, braced and made ready for cladding or brick skin, with a company crane on hand for the lift. Includes re-forming first floors in barn conversions.
The contractor-facing version of the same work, packaged with door linings, noggins, firrings and boarding to take a plot from shell to plasterable.
Evidence
Large single builds. A 6,000 square foot house for SSL Home Creations with six bedrooms, nine bathrooms, a private gym and a pool, described by the company as possibly its largest single build carpentry package. The first visit completed a 288 square metre joist set across two days.
Steel and structural floors. At Gladstone House in North London an empty shell was turned into four luxury apartments starting with joists and floors, completed by a team of three in five days flat. On the second joist set in Tottenham, the steel was infilled with hand cut joists and hangers and boarded in 18mm marine ply. A further joist and roof set followed on the same building six storeys up.
Conversions. Barn conversions near King's Lynn for Eastern Construction Consultants have taken traditional joist sets re-installed to form entirely new first floors in tight existing buildings, creating two bedrooms and an en suite upstairs, followed by structural floors, ceilings and external walls at first fix. Seven apartments outside South Lynn took the full carpentry contract with joists and roofs completed first.
Housing and industrial. At Grantham the structural scope was new internal joists and flooring plus stud partitions to all external walls and the stud layout for nine apartments. At Fleet Hargate the package included 8 joist sets with a further 3 in Spalding, 11 sets in total across industrial units. A week of external fixtures across Cambridgeshire and Lincolnshire took in a posi-joist set at Stilton near Peterborough and a hand cut joist set in Spalding on the same run.
Extensions and garages. A timber frame front and rear extension wrapped in cedar cladding, a full wrap-around traditional joist set ready for a first floor lift on a 1960s renovation, a 4.2 metre glulam beam used as a ridge with ceiling ties on a hand cut extension roof at Long Sutton, and a triple garage with a double squint block joist set completed in a morning.
Send the architectural drawings, the joist and truss design and the structural engineer's details. What comes back is a package price with the scope broken out, so a quantity surveyor can see which structural items are inside the carpentry package and which are being bought elsewhere. Work is taken supply and fit or labour only.
Structural carpentry usually sits at the front of the carpentry programme, which makes it the package most likely to be waiting on somebody else: the groundworker, the bricklayer's block and beam, or the steel. AJB Group sequences against your build programme and, because the carpenters are employed rather than hired job by job, teams can be pulled forward or held back without losing the gang to another site. The company crane means the joist or frame lift is not sitting in a hire queue either.
On multi-plot developments the external teams normally stay ahead on joists and roofs while the internal teams follow through first fix, which is how a site keeps a steady flow of plots reaching water tight rather than all arriving at once.
AJB Group is CHAS accredited and SMSTS certified, retains an external health and safety consultant and issues project-specific RAMS before mobilisation. Carpenters are expected to read working drawings as a matter of course, which is stated plainly in the company's own recruitment requirements.
Setting out is treated as a managed activity rather than a habit. Director Ashley Box holds a Level 6 NVQ Diploma in Construction Site Management (Building and Civil Engineering), awarded on 20 July 2026 by Highfield Qualifications and assessed across 22 workplace units. Two of those units sit directly on this page. Establishing dimensional control criteria is the unit behind setting out and tolerance: agreeing the datum and the acceptable deviation before anybody cuts, which is why a joist set lands square on the block work and why trimming to an opening still measures right three plots later. Managing the installation, maintenance, monitoring and removal of temporary works is the unit behind propping, formwork and shuttering, all of which carry load until the concrete cures or the permanent structure takes over. At NHS Hinchingbrooke Hospital that meant 450 x 450 shutter boxes set with the site engineers to millimetre tolerance ahead of 58 pours. It is a competence qualification assessed on real project evidence, not a short course, and the full detail is on the accreditations page.
Structural carpentry on your own extension, garage conversion or self build is the same work with a shorter list. You get one point of contact, a free site visit and a written estimate before anything starts, plus in-house trades for the brickwork, plumbing, electrics, plastering and decorating that follow the structure. Start at extensions and renovations, or see roofing carpentry if the roof is the part you are worried about.
Related case studies: 17-19 High Street, Grantham and the Tottenham mansard roof. Back to all carpentry services.
Common questions
Any carpentry that carries load or forms the structure of the building: floor joists and structural floors, timber frame walls, roof structure, load-bearing stud partitions, timber infill to structural steel, trimming to openings and staircases. It is designed by an engineer and built to that design, unlike trim carpentry which is built to a finish.
Whatever the structural design calls for. A typical traditional set is C24 8x2 at 400mm centres with 22mm Caberdex flooring. We also fit posi-joist sets, traditional hand cut sets, and hand cut joists with hangers infilling structural steel, boarded in 18mm marine ply where specified.
On a 6,000 square foot house for SSL Home Creations the team completed a 288 square metre joist set across two days on the first visit. At Gladstone House in North London, joists and floors for four luxury apartments were formed by a team of three in five days flat.
Yes. We have built a front and rear extension in timber frame, wrapped in cedar cladding, and re-installed traditional joist sets to form new first floors in barn conversions near King's Lynn. There is a company crane on hand for lifting frames, joists and trusses into position.
Yes, and that is the normal arrangement. Send the architectural drawings, the joist and truss design and the engineer's details, and we return a package price and build to that design. Setting out is done on site by carpenters who read working drawings, not from a sketch. Establishing dimensional control criteria, which is the formal name for agreeing tolerances before work starts, is one of the 22 units assessed in our director's Level 6 NVQ Diploma in Construction Site Management.
Regularly. Barn conversions near King's Lynn have taken traditional joist sets re-installed to create new first floors in tight existing buildings. At 17-19 High Street in Grantham the scope included new internal joists and flooring plus stud partitions to all external walls inside a disused town centre building.
Send the drawings and the engineer's details and we will price the structural package.
