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Free scaffolder calculator
Scaffolding calculator: bays, tubes, boards, fittings and ties
Put in the length and height of the elevation, how many lifts you want and what it will carry, and get a component list for a tube and fitting scaffold: standards, ledgers in metres and tubes, transoms at 1.2m centres, boards run along the scaffold, couplers, braces and ties to the TG20 pattern. It is a materials take-off for an independent tied scaffold on a straight run, not a design: anything off the TG20 compliance sheet needs a scaffold design.
What you need
Layout
- Bays
- 5 bays2.4m bays along 12m, 3 lifts at 2mTG20:21 independent tied scaffold
- Load class
- 1.5 kN/m² General purpose, 1.5 kN/m² (bricklaying, roofing)TG20:21 load classes (squote)
Tubes
- Standards
- 12 positionsinside and outside at every bay division
- Standard tubes
- 24 × 6.4m tubes2 per standard for 6m plus 1m for the top guardrail
- Ledgers and guardrails
- 25 × 6.4m tubes155m: inside and outside ledgers on 3 lifts, two guardrails and end rails on every boarded lift, run as long tubes not one per bay
- Transoms
- 33 tubes2 per bay per lift: one at every standard and intermediates so boards are supported at 1.2m or closerTG20:21 transom spacing for 38mm boards
- Ledger braces
- 9 tubesat alternate pairs of standards on every lift
- Facade (sway) braces
- 4 tubes1 set, one per six bays, full height
Boards
- Scaffold boards
- 51 × 3.9m boards4 wide × 4 along the run per lift, includes 5% spareTG20:21 (boards run along the scaffold, 3.9m)
- Toe boards
- 18 boardsoutside and both ends on every lift
- Toe board clips
- 36 pcs
- Sole boards
- 6 pcs225 × 38mm timber under each pair of base plates
Fittings
- Right angle (double) couplers
- 108 pcsledgers to standards, main transoms to ledgers
- Putlog (single) couplers
- 30 pcsintermediate transoms
- Swivel couplers
- 26 pcstwo per brace end
- Sleeve couplers
- 24 pcsone at every tube joint in the standards and ledgers
- Base plates
- 12 pcs
Ties
- Wall ties
- 8 ties4 per tie row at every other standard plus the ends, 2 rows at every other lift (4m). Anchor ties (ring bolts into the wall)TG20:21 tie pattern (squote; CISRS)
- Tie tubes and couplers
- 16 couplersa tie tube and two right angle couplers per tie; anchor ties need ring bolts tested to 6.1 kN
Access
- Ladders
- 3 laddersone per lift with a ladder trap or hatch, or an internal ladder bay
- Platform area
- 10.8 m²per lift
Design
- TG20 compliance
- required an independent tied scaffold on a straight run to TG20:21 with a compliance sheet and scafftag; returns, bridges, cantilevers, loading bays and anything sheeted need a designNASC TG20:21
Round up to whole packs and bags. Figures include the wastage you chose and match TradeCalc in the app.
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Or claim your free profile link nowHow the maths works
- Bays are the run (length plus one bay per return) divided by the bay length, rounded up. TG20 general-purpose scaffolds use bays up to 2.4m and 2.0m lifts; heavy duty comes down to 2.1m bays (squote; bobscaffolding). Standards sit inside and outside at every bay division.
- Standards are 6.4m tubes for the working height plus 1m for the top guardrail, rounded up, with a sleeve coupler at every joint. Ledgers and guardrails are worked out as linear metres, inside and outside on every lift plus two guardrails and end rails on every boarded lift, then converted to 6.4m tubes with a sleeve at each joint; a ledger is a long tube, not one per bay.
- Transoms sit on the ledgers at every standard and at intermediates so boards are supported every 1.2m or closer (TG20 for 38mm boards): a 2.4m bay needs two per lift plus one at the end. Main transoms go on right angle couplers, intermediates on putlog couplers.
- Boards are 3.9 × 0.225m and run along the scaffold end to end, so the count per lift is the run ÷ 3.9 × the platform width, not one set per bay. 4 boards for light work, 5 for bricklaying and roofing (1.5 kN/m²), plus an inside board to close the gap. 5% is added for damaged or borrowed boards. Toe boards run outside and at both ends of every lift with two clips each.
- Ledger bracing goes at alternate pairs of standards on every lift and facade (sway) bracing one full-height set per six bays (bobscaffolding), each end on a swivel coupler.
- Ties follow the TG20 pattern: every other standard plus the ends, every other lift (4m vertically), so a 12m, 3-lift scaffold gets 8 ties (squote; CISRS). Each tie is a tube and two couplers to a box tie, a through tie in an opening, or an anchor (ring bolt) tested to 6.1 kN. Netting, sheeting, a pavement lift, loading bays and returns take it outside the TG20 compliance sheet, which means a scaffold design.
- One ladder per lift with a trap. Everything gets a compliance sheet and a scafftag, and it should be erected, inspected and struck by a scaffolding firm.
Worked example
A 12m long, 6m high scaffold with 3 lifts, 2.4m bays and a 4-board platform is 5 bays with 12 standard positions. That needs 24 standard tubes, 25 tubes of ledgers and guardrails (155m), 33 transoms, 51 boards, 9 ledger braces, 8 wall ties, 108 right angle couplers, 30 putlog couplers and 12 base plates.
Questions people ask
How many scaffold boards do I need?
Boards run along the scaffold end to end, so each lift needs the run ÷ 3.9m rounded up, times the platform width in boards. A 12m run with a 4-board platform is 4 × 4 = 16 boards per lift, 48 for three lifts, plus 5% spare. Counting a set of boards per bay over-orders by about 60% with 2.4m bays.
How far apart should scaffold ties be?
TG20:21 ties an independent scaffold at every other standard horizontally (about 4.8m with 2.4m bays) plus the ends, and every other lift vertically (4m), or every bay and every third lift. Anchor ties into the wall are pull-tested to 6.1 kN. Sheeted or netted scaffolds, cantilevers and loading bays need more ties and a design.
What is a lift?
One working level of the scaffold: a set of ledgers and transoms with boards on top, two guardrails at 950mm and under 470mm gaps, and a toe board. Lifts are 2m apart, so a 6m scaffold has three. A first lift of 2.7m is allowed over a pavement so people can walk underneath.
What load class do I need?
Light duty (0.75 kN/m²) is fine for painting, pointing and gutters on a 4-board platform. General purpose (1.5 kN/m²) covers bricklaying, rendering and roofing on 5 boards. Heavy duty (3 kN/m²) is for stone, blockwork stacks and loading bays and drops the bay length to 2.1m. Materials stacked on a lift also need brick guards above the toe board.
Can I hire scaffolding and put it up myself?
Most hire yards will not supply tube and fitting to anyone without a CISRS card, and for good reason. For a house, get a scaffolding firm to erect, inspect and strike it with a TG20 compliance sheet and a scafftag. Use this list to check what they are quoting for.
How much does scaffolding cost?
It is usually priced per elevation for a set hire period, with extras for longer hire, returns, netting and chimney stacks. Prices vary by area and access, so get two or three quotes and check the hire period covers your job.
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