Most clients commission a timber frame having never seen one go up. The process is nothing like standard building construction — the frame is not assembled on site from individual pieces. It is built, assembled, disassembled, and transported as a complete system, and then raised in a single continuous operation. Understanding this sequence makes the raising day make sense, and it explains why the preparation before that day matters as much as the raise itself.
Before the raise
By the time the delivery vehicle arrives at your site, the frame has already been assembled once — in the workshop yard at Welshpool. Trial assembly is the process of fitting the complete frame together in the controlled conditions of the yard: every mortise checked against its tenon, every post checked for plumb, every rafter seated correctly in its bearing. Any errors found at trial assembly are corrected in the yard, where the tools, the timber, and the daylight are all available. Errors found on site are a different order of problem.
After trial assembly, the frame is numbered. Every component receives a reference that corresponds to the assembly drawing — the number stamped or written on the timber tells the raising crew exactly where that piece belongs and in what order it goes up. After numbering, the frame is disassembled in reverse assembly sequence: the last piece up is the first piece to go back on the vehicle. What loads last on the flat-bed is what comes off first on site. This sequencing is not accidental — it determines how efficiently the raising day runs.
What the site needs
The foundation must be complete, level to within 5mm across the frame footprint, and with any base plates or anchor bolts installed in the correct positions. We provide a setting-out drawing well in advance of the raise date — the positions of every post base are on that drawing, with dimensions from fixed reference points on the site. The foundation contractor works from this drawing. Any discrepancy between the drawing and the installed base plates is found before the delivery vehicle arrives, not after.
Access for the delivery vehicle — a flat-bed lorry carrying the full frame — and for the lifting equipment is the second requirement. For most residential gardens, a 7-tonne telehandler is appropriate: compact enough to get through a standard agricultural gate, with sufficient reach and lift capacity for frame components up to around 3m. For larger frames or constrained sites, a mobile crane or a straight-mast forklift may be more appropriate. We advise on the right machine at the site visit stage.
The raising crew is typically four to six people for a standard residential frame — two from us, two to four from the client’s main contractor or from a labour-only contractor. The crew does not need specialist timber frame experience; they need to be able to follow instructions, handle heavy components safely, and hold a post plumb while it is temporarily braced. Citadel leads the raise. The crew takes direction from them.
The raising sequence
Posts go up first. Each post is lifted to its base plate by the telehandler, lowered onto the plate, and checked for plumb in two directions before temporary bracing is fixed. The temporary bracing — typically 100×50mm softwood raking braces pinned to a peg in the ground — holds the post in position until the tie beam locks it in place permanently. The posts stand in a line along the foundation, temporarily braced, like an incomplete sentence waiting for its verb.
Tie beams follow. Each tie beam spans between two posts, its tenons dropping into the mortises cut in the post heads. The telehandler lifts the beam to position; the crew guides the tenons into the mortises by hand. When both tenons are seated, the beam is pegged: a seasoned oak peg is driven through a hole that passes through the mortise cheek and the tenon. The peg locks the joint. The temporary bracing on the posts can be checked and adjusted at this point as the frame begins to form a rigid structure.
Principal rafters come next. Each rafter is seated at the foot in its wall plate bearing and at the head against its ridge post or ridge beam. The sequence varies depending on the frame design — a king post truss goes up differently from a simple coupled rafter frame — but the logic is the same: bottom-to-top, perimeter-to-centre, major structure before minor structure.
Ridge, purlins, and common rafters complete the skeleton. By the time the last common rafter is in position, the frame is structurally complete. The temporary bracing is removed. The frame stands on its own.
Pegging
Pegged joints are the defining detail of traditional timber frame construction. The peg — typically 25–32mm diameter, turned from seasoned oak — is driven through a hole bored through the assembled mortise-and-tenon joint. Driving the peg slightly offset from the hole in the tenon — a technique called “draw-boring” — pulls the joint tight as the peg straightens in the hole. As the green oak frame dries over the following months, the mortise and tenon shrink around the peg, which remains at its original dimensions. The result is a joint under permanent compression.
The peg does not need to be removed for the joint to be inspected later — the joint is visible at its external faces. In the unlikely event that a joint needs attention after installation, the peg can be drilled out and replaced. In most cases, a correctly assembled pegged joint never needs attention.
The timeline
A simple garden room frame — two bays, four posts, a ridge, eight common rafters — can be raised in half a day by an experienced crew. A full single-storey rear extension of three to four bays with principal rafters, knee braces, and wall plates takes a full day. A two-storey structure or a complex trussed roof takes one to two days. These are realistic estimates for a prepared site with the right machinery and crew; they extend if the site is constrained, the access is difficult, or the crew is unfamiliar with the sequence.
What the client sees
For most clients, the raising day is the most memorable day of the project. A flat-bed of numbered timbers arrives in the morning. By the afternoon, those timbers are a structure — standing, rigid, its scale apparent for the first time in three dimensions rather than on a drawing. Clients who have been patient through the months of consultation, design, and fabrication often find the raising day the moment at which the commission becomes real. They are welcome on site throughout the day. Citadel will talk them through the sequence, explain what is happening at each stage, and let them stand inside the frame when it is safe to do so.
After the raise
The frame is left open for Specification details are available on request from the workshop. before infill panels, cladding, and roofing go on. This open period allows the green oak to begin its initial drying movement — checking, slight twisting, settling at the joints — before the frame is enclosed. A frame enclosed immediately after raising traps the drying movement inside and can transfer stress to infill panels and roofing details as the timber moves against them. Leaving the frame open for the initial drying period is not standard practice in all parts of the industry, but it is our practice. It produces better results.