Start with the section, not the length
Each row belongs to a timber section such as 47 × 75 mm or 47 × 100 mm. Those two dimensions describe the finished cross-section; the separate cut length describes how long the member is. Keep the orientation in mind because the deeper dimension normally works in the primary bending direction for joists and rafters.
Check family and finish with the supplier. CLS, regularised carcassing and rough-sawn timber can have different actual dimensions even when casual nominal descriptions sound similar. Substituting a section changes junctions, wall depth and calculated member lengths, so update the design rather than editing the purchase list alone.
Read grade and treatment together
A grade such as C16 or C24 relates to structural properties. A treatment class relates to biological exposure and expected moisture conditions. The schedule shows both because a floor member can need a different durability specification from a protected wall stud even if their dimensions match.
When requesting prices, state section, grade, treatment, quantity and acceptable stock lengths in one line. Ask whether treatment certificates and strength stamps remain identifiable. If cut ends need retreatment, include the compatible product and drying time in the work plan.
Exact cuts are not the merchant order
The exact-cut list groups repeated finished lengths. It is useful for making stops, templates and batches, but merchants normally sell stock lengths. Several short cuts can come from one 4.8 m piece, while a long member may require its own 3.6 m or 4.2 m length. The objective is to nest cuts with manageable waste.
Make My Shed uses a simple stock optimiser and a 3 mm saw kerf. It places longer cuts first into common UK lengths. Real timber introduces more choices: defects may force a cut to move, clean ends need trimming and appearance-sensitive members may be selected from better boards. Treat the stock count as an informed estimate and inspect the proposed combinations.
Use assembly groups to control the build
The static table separates floor and base, wall framing and roof structure. That reflects how the shed is assembled and makes deliveries easier to check. Within each group, label members by role: bearer, joist, stud, plate, noggin, header, rafter or ridge. Two pieces of identical timber are not interchangeable if drilling, treatment or end cuts differ.
Create a cutting sheet for each assembly and mark every finished piece immediately after cutting. Use a pencil code on an end or face that will remain hidden. Keep paired rafters and opening members together. This reduces the chance of using a carefully selected long member for short blocking early in the job.
Check dimensions against the setting out
Calculated lengths assume the modelled finished dimensions and square assemblies. Before batch cutting, confirm the base, actual timber size, sheet layout and opening components. If the floor cassette finishes larger or smaller than planned, blindly following wall and roof cuts transfers the error upward.
Cut and trial-assemble one example of repeated geometry. A single common stud verifies wall height; one rafter pair verifies ridge position; one noggin verifies the clear bay. When the first piece is correct, use a stop or template rather than measuring every repeat independently.
Turn the schedule into a purchasing list
Export or transcribe each section group and choose stock lengths based on the optimiser, merchant availability and transport. Add a modest allowance for defects and late changes based on product quality and project risk rather than an arbitrary blanket percentage. Separate treated and untreated pieces even where the section matches.
Finally, add everything the structural timber schedule does not contain: sheets, cladding, membranes, roof finish, battens, trims, doors, glazing, ironmongery, fixings, connectors, preservatives and base materials. The schedule is powerful because it is specific about one category; it remains honest by not disguising the rest as an exact bill of materials.
Control revisions on site
Print or save a dated schedule for the version you intend to build and give that revision a clear name. If width, roof, opening or timber section changes, generate a new schedule rather than writing over the old one. Mark obsolete copies so two people cannot cut from different versions. A small revision table with date, reason and affected assemblies prevents expensive ambiguity.
As pieces are cut, tick them off by assembly and note any replacement stock used because of defects. Keep offcuts labelled until the frame is complete; a piece that looks like waste may be a scheduled header packer or block. At the end, reconcile the unused timber with the order. That feedback improves the waste allowance and stock choices for the next project far more than a generic percentage ever can.
Use the schedule as a checking tool
Before cutting, scan for surprising one-off lengths, unexpected grades or quantities that do not match the drawing. A sudden cluster of very short studs may be correct around an opening, but it may also expose a wrong sill height or roof setting. The schedule is easier to audit when the 3D frame view is open beside it and each group can be traced visually.
After assembly, compare the built frame with the schedule before cladding hides it. Confirm openings, restraint, support and any approved changes. Photograph the frame with labels visible and retain the final schedule. It becomes a useful record for locating studs, planning future fixings and explaining how the building was intended to work.