Updated 2 Nov 2026
A scaffold design should be checked by a competent engineer who did not produce it. A design is needed when the scaffold is outside a standard configuration, for example unusual loads, cantilevers or suspended scaffolds. BS 5975 sets the temporary-works procedure; Saudi guidance and the client's rules add their own requirements.
When is a design needed?
A scaffold built inside a standard configuration, such as the NASC TG20 guidance, does not need a one-off design. A scaffold outside it does: unusual loads, cantilevers, very large heights or ties to a structure nobody has checked. The SASO scaffold guide (Arabic) asks for an engineer's design for suspended scaffolds, for mobile scaffolds that carry workers, and for fixed and metal scaffolds above the heights it sets. The heights are in the original guide, so read them there. See our summary in 6 points.
| Situation | Design or check needed? | Where it comes from |
|---|---|---|
| Inside a standard configuration (TG20 guidance) | No bespoke design; keep the compliance record | NASC TG20; verify against the latest edition |
| Outside a standard configuration (unusual loads, cantilevers) | Yes, a designed scaffold with an independent check | BS 5975 temporary-works procedures; verify against the latest edition |
| Suspended scaffold | Engineer's design | SASO scaffold guide (Arabic) |
| Mobile scaffold carrying workers; fixed and metal scaffolds above the guide's heights | Engineer's design | SASO scaffold guide (Arabic); read the heights in the original |
| Saudi Aramco and other client sites | The client's own approval route also applies | Saudi Aramco CSM and GI 8.001 on Aramco sites; verify against the latest edition |
Who can check a design?
A competent engineer with scaffold or temporary-works experience, who did not produce the design. BS 5975 organises this as a temporary-works procedure with a coordinator and design check levels. Your project procedure names the person and the level, and the client may need to approve the checker.
Six steps for a shutdown scaffold design check
- List the scaffolds outside standard configuration. Take them from the access plan.
- Issue a design brief. Loads, tie points, and what supports the scaffold.
- The designer submits calculations and drawings. One drawing per scaffold or per type.
- An independent checker reviews and signs. Hold point: no erection before this.
- Erect to the checked drawing. Any change goes back to step 3 (see tie moves and modifications).
- The inspector tags against the drawing. See inspection frequency.
Common mistakes on site
- The designer and the checker are the same person.
- A drawing is issued, then the crew adds a loading bay without telling anyone.
- Ties assumed on a pipe rack or structure that nobody checked.
Questions
Is a TG20 compliance sheet a design?
For a scaffold inside the standard configuration it takes the place of a one-off design. Confirm with your client what it will accept.
What is BS 5975?
A British Standard code of practice for temporary works procedures. It sets out roles such as the temporary works coordinator and levels of design checking. Verify the current edition.
Where do I find the Saudi heights that need an engineer's design?
In the original SASO guide (Arabic). We do not copy the values here; read them there and check the latest edition.
Does AL-YASSIN check designs?
AL-YASSIN is not taking paid work or payments at this time. Design checking by an independent engineer is described on the expertise page.
- SASO: Occupational safety and health guide: scaffolds (Arabic, PDF); edition date not shown on the copy read
- HSE Blog: Temporary Works: Types, Hazards & Controls (BS 5975:2024) (a secondary source; confirm against BS 5975 and TG20)
General guidance for learning, not legal or engineering advice. Verify every value against the latest edition and your client's own rules. AL-YASSIN is independent and is not endorsed or approved by Saudi Aramco, OSHA, BSI, NASC, CISRS, CSCS or any other body.