Tube and fitting scaffold: tubes, boards and fittings for a 10 m wall

What does this count assume?

A tube and fitting count is only as good as the configuration behind it. Rather than invent one, this example borrows the limits from a real TG20:21 compliance sheet, prepared by an NASC member contractor and published with a 2025 planning application in Greater Manchester, for a tied independent tube and fitting scaffold (TG20:21 compliance sheet, 1 February 2025). That sheet allows:

• a maximum height of 6 m, with up to 3 boarded lifts;
• a maximum lift height of 2 m and a maximum bay length of 2 m;
• up to 4 + 2 boards wide; one lift loaded to 2.0 kN/m² (load class 3, general purpose) plus one lift 50 % loaded per facade, and inside boards at most 0.75 kN/m² at the working lift;
• a maximum transom spacing of 1.2 m;
• facade bracing every 6 bays per elevation, and ledger bracing at alternate standards and end frames;
• double guard rails and toe boards at boarded lifts, and single guard rails at unboarded lifts;
• butting structural transoms at every standard at every lift, except where a tie tube is present;
• ties at alternate lifts to TG20 tie pattern A, and at the top lift at the ledger-braced standards;
• 5.7 kN standard-duty ties, with tie tubes connected to the inner and outer faces;
• the scaffold fully or partially clad with sheeting (wind factor 25, moderate);
• all abutting tubes fitted with end caps.

On top of that sheet, these are our own assumptions for the worked example:

A different sheet, for example one with a higher wind factor or with netting instead of sheeting, gives different numbers, so treat the result as a worked method, not a quantity you can order from.

Standards: how many, and how long?

Five bays of 2.0 m need six standard positions along the wall, and an independent scaffold has an inner and an outer row: 12 standards.

Height decides the length. The top working lift is at 4.0 m and needs a guard rail at least 950 mm above it, which is the minimum height HSE gives for a top guard rail (HSE scaffolding guidance). A 16 ft tube (about 4.9 m) would stop just short of that top rail, so each standard is one 21 ft tube (6.4 m), with no joints. An 18 ft tube (about 5.5 m) also clears the rail; we use 21 ft so the example uses only two long lengths. A taller scaffold adds a joint in the standards, and each joint adds a sleeve coupler or joint pin and should be staggered, which is where hand counts often slip.

Ledgers and guard rails

Ledgers run along the wall at every lift, on both rows of standards. Two lifts × two rows gives four ledger runs. Each run is 10 m plus a little overhang at the ends, which in UK lengths is one 21 ft tube and one 13 ft tube (6.4 + 3.9 = 10.3 m) joined with a sleeve coupler.

• Ledgers: 4 × 21 ft, 4 × 13 ft, 4 sleeve couplers, and a right-angle coupler at each of the six standards per run: 24 right-angle couplers.

The guard rails sit on the outer face. The sheet asks for double guard rails at boarded lifts, and HSE sets the top rail at 950 mm minimum with no unprotected gap above 470 mm, which in practice means a main rail and an intermediate rail (HSE). Two lifts × two rails gives four runs, made up the same way as the ledgers.

• Guard rails: 4 × 21 ft, 4 × 13 ft, 4 sleeve couplers, 24 right-angle couplers.
• End guard rails: both ends of both boarded lifts, two rails each, across the scaffold width: 8 short tubes (5 ft), 16 right-angle couplers.

Transoms: why the 1.2 m spacing matters

Transoms carry the boards across the scaffold. Two rules from the sheet fix their number. Butting structural transoms are needed at every standard at every lift, and transoms may be no more than 1.2 m apart. With 2.0 m bays, the second rule means one intermediate transom in each bay, near the middle; the board layout below shifts two of them.

• Butting transoms at the standards: 6 per lift × 2 lifts = 12. Because they butt against the facade, we allow 6 ft tubes. Each is fixed to the ledgers with two right-angle couplers: 24 couplers.
• Intermediate transoms: 5 per lift × 2 lifts = 10, in 5 ft tubes, each fixed with two putlog couplers: 20 putlog couplers.

The 1.2 m figure matches the span suppliers quote for a 38 × 225 mm board graded to BS 2482:2009 (board specification). Check the grade printed on the boards you actually have.

Boards and toe boards

The platform is four boards wide, in 225 mm wide, 38 mm thick boards. Each row takes two 13 ft boards and one 8 ft board (3.9 + 3.9 + 2.4 = 10.2 m), starting 100 mm before the first standard. The butt joints fall at 3.8 m and 7.7 m, so each joint gets a pair of short joint transoms (about 3.7/3.9 m and 7.6/7.8 m). The intermediate transoms move to about 1.0, 2.85, 5.0, 6.8 and 9.0 m, so no gap exceeds 1.2 m. Three 13 ft boards per row would not work: 11.7 m of board on a 10.2 m platform leaves joints between transoms and a board end hanging past the last one.

• Joint transoms: 4 per lift × 2 = 8, in 5 ft tubes, with 16 putlog couplers.
• Platform boards: 4 rows × 2 lifts = 8 rows, each with two 13 ft boards and one 8 ft board: 16 boards of 13 ft and 8 of 8 ft.
• Toe boards: along the outer face at both boarded lifts, 3 boards per lift = 6 boards of 13 ft, lapped where they meet.
• End toe boards: 4 short boards, one at each end of each lift, plus the toe board clips your yard uses.

Bracing

The sheet calls for two kinds of bracing.

• Ledger bracing runs across the scaffold, from the inner to the outer row, at alternate standards and at the end frames. With six standard positions that is positions 1, 3, 5 and 6: four frames, braced in both lifts, so 8 braces. Across about a metre of width and a 2 m lift, each brace is about 2.3 m long, so an 8 ft tube. With two couplers each, that is 16 couplers; we count them as swivels onto the standards.
• Facade bracing runs diagonally along the outer face, every 6 bays. Five bays need one brace: a 21 ft tube climbing from the base towards the top lift, fixed with about 4 swivel couplers where it crosses the standards.

Base plates, sole boards and ties

Every standard stands on a base plate: 12. Under the plates, HSE asks for a firm, level foundation that can carry the scaffold and its loads, with extra support over voids, drains or soft ground (HSE); the sheet itself gives a maximum leg load of 7.6 kN to be passed to the client for the foundation design. We allow 6 timber sole boards, one under each pair of standards; on sound concrete you may need none.

Ties are deliberately not counted here. The sheet asks for ties at alternate lifts to TG20 tie pattern A, plus ties at the ledger-braced standards on the top lift, and the tie positions depend on that pattern, the facade and its openings. The sheet also states that the facade must not have significant openings. Each tie adds a tie tube, couplers and a fixing, and a site form from the States of Guernsey lists the kinds you choose between: box ties, through ties, lip ties and drilled anchor ties (Guernsey scaffold notification).

The whole list for the 10 m wall

That is 75 tubes, 34 boards and 152 couplers (often called clamps on yard lists) before ties, access and any loading bay. The current coupler standard, BS EN 74-1:2022+A1:2025, covers right-angle, swivel, sleeve and parallel couplers working by friction (BSI, BS EN 74-1:2022+A1:2025); putlog couplers are outside Part 1's scope.

What changes the count most?

• Another boarded lift. Each extra boarded lift adds two ledger runs, two guard rail runs, fifteen transoms, eight 13 ft and four 8 ft platform boards, three toe boards, four end-rail tubes, four ledger braces and about 74 couplers, and the standards may need a joint.
• Inside boards. The sheet allows 4 + 2 boards. Two inside boards on brackets add boards and fittings on the building side and change the transom length.
• Sheeting or netting. The base sheet for this example is the sheeted one, which is why it asks for 5.7 kN standard-duty ties. The 2023 sheet we read, for a scaffold clad with high-permeability debris netting, gets by with very light duty ties of 2.2 kN, although the two also differ in wind factor and height.
• Access. A ladder-access tower has its own compliance sheet. One example sheet for an external tower allows at most two 2.0 m bays and 15.3 kN leg loads (TG20:21 compliance sheet, 14 July 2023), so it is counted as a separate structure.
• Returns. A corner adds standards, transoms in two directions and boards around the turn; our guide to scaffold corners and returns walks through it.
• Tube type. The 2025 sheet specifies type 4 galvanised steel tubes and the 2023 sheet high-tensile tubes. Some suppliers sell 48.3 mm tube with a 3.2 mm wall in lengths down to 5 ft (example listing); whatever is in the yard must match the tube the sheet was produced for.

How do you check a tube and fitting count?

1. Start from the compliance sheet, not from memory. The sheet states it is "in accordance with TG20:21 chapters 06 and 07"; NASC's 220-page TG20:21 operational guide accompanies the TG20 eGuide. The bay length, lift height, transom spacing and bracing on the sheet drive every line above.
2. Count by element, then by joint. Tubes come first, then one coupler per crossing: ledgers to standards, transoms to ledgers, braces to standards. A quick check is that right-angle couplers should roughly equal the number of ledger and guard rail crossings plus two per transom at the standards, plus two per end guard rail: 48 + 24 + 16 = 88 here.
3. Compare against a known job. If your last 10 m wall at two lifts went out with around 150 couplers, a list of 100 is missing a category. Where take-off errors usually start, from the survey to the count, is the subject of how accurate is a scaffold take-off?
4. Keep ties and access separate. They depend on the facade and the sheet, and they are where the cost and the risk sit.

For the names of the components, our scaffold parts guide and the glossary entry for ledgers explain each one.

System scaffold or tube and fitting: which is quicker to plan?

A system scaffold is counted from kit components with fixed bay lengths and frame heights, so the list follows from the layout. Our Layher Blitz material list example reads a computed list for a 10.28 m wall, 8 m high, in four 2.57 m bays: 122 pieces, including 12 wall ties. Tube and fitting has no kit list. The same 10 m length here, only two boarded lifts high and before ties, already runs to 75 tubes, 34 boards and 152 couplers, and every one of those couplers is a line someone has to count, choose and check.

The trade-off runs the other way on site. Tube and fitting can follow an awkward facade, step around obstructions and use any bay length the sheet allows. If the job fits a standard system layout, planning it from kit components is usually quicker to count and to check; how much scaffolding do I need covers that route. ScaFix plans system scaffolds from wall dimensions but has no UK tube and fitting model, so its engine was not used for this page.

When is a design needed instead?

The Work at Height Regulations 2005 require strength and stability calculations unless a note of calculations for the arrangement is available or the scaffold is built to a generally recognised standard configuration (Schedule 3, paragraph 7). HSE names TG20 as that configuration for tube and fitting and lists structures that normally need a bespoke design, such as scaffolds outside the TG20 criteria, and it notes that a TG20:21 scaffold may be boarded at any number of lifts but used as a working platform on only two at once (HSE). The working platform must also be inspected in position before use and within the previous 7 days whenever someone could fall 2 m or more (regulation 12).

This count illustrates a method; it is not a design or a compliance sheet. In Great Britain the Work at Height Regulations 2005, enforced by HSE, and the NASC's TG20:21 compliance sheet for your actual scaffold decide what is built, and a competent person must inspect the scaffold before use and at least every 7 days.

Frequently asked questions

Sources

Primary sources used for this article, with the date each was read.

• TG20:21 compliance sheet, tied independent scaffold, prepared by an NASC member contractor (planning application, 1 February 2025) (read 23 October 2026)
• TG20:21 compliance sheets incl. ladder-access tower (planning application, 14 July 2023) (read 23 October 2026)
• HSE: Scaffolding (read 23 October 2026)
• legislation.gov.uk: Work at Height Regulations 2005, Schedule 3 (read 23 October 2026)
• legislation.gov.uk: Work at Height Regulations 2005, regulation 12 (inspection) (read 23 October 2026)
• NASC: TG20:21 Operational Guide (read 23 October 2026)
• BSI: BS EN 74-1:2022+A1:2025, couplers for tubes (read 23 October 2026)
• Flints: galvanised scaffold tube 48.3 mm, 6.4 m (21 ft) (read 23 October 2026)
• First Fence: 21 ft scaffolding tube, 48.3 × 3.2 mm, 22.68 kg (read 23 October 2026)
• Bendrey Bros: scaffold board 38 × 225 mm × 3.9 m, BS 2482:2009 (read 23 October 2026)
• States of Guernsey: scaffold notification form (read 23 October 2026)