Updated 2 Nov 2026
Appoint a scaffolding contractor on evidence, not on price or availability. Check verifiable supervisor and inspector competence, experience on similar plant, safety record, design and checking route, inspection and tagging, yard control, and clear contract terms. Then ask to see the documents: a sample tag register, certificates and a written rescue plan.
Why evidence beats a quote
NASC guidance SG39:21, Guidance on Appointing a Scaffolding Contractor, says to judge a contractor on competence, experience, training, safety performance, legal compliance and clear contract terms. It is a UK document. On a Gulf site the client's own contractor rules apply as well, so use it as a structure, not as the rule.
The 10-point appointment check
Send it with the tender, then ask to see the evidence, not only the answer.
| # | Ask for | Good evidence looks like | Red flag |
|---|---|---|---|
| 1 | Supervisor and inspector competence | A card or certificate you can verify, for example on our Verify page for AL-YASSIN certificates | "All our men are experienced" |
| 2 | Experience on similar plant | Scope described by type (refinery, tank farm, shutdown) and country | Only house-building references |
| 3 | Safety record | Their own figures with the period and the definitions stated | Figures with no period |
| 4 | Design route | Who designs, and who checks anything outside a standard configuration (see who checks a scaffold design) | Designer and checker are the same person |
| 5 | Inspection and tagging | A sample tag register, the tag colours, and who may sign (see tag colours) | Tags signed by the erectors only |
| 6 | Material control | A yard system with issue and return records | Stock counted "at the end" |
| 7 | Rescue and working-at-height plan | A written plan that names the equipment and the people | "Call the site rescue team" |
| 8 | Heat and weather rules | Written stop-work triggers for your site and season | No written trigger |
| 9 | Measurement and variations | How quantities are measured and agreed (m³, m², lm) | Open-ended day rates |
| 10 | Contract terms | Clear scope, handover, tag ownership, off-hire | Vague wording such as "as directed" |
Five steps
- Write a scope a bidder can price. Type, height, duration, access dates.
- Send the 10-point check with the tender. Same questions to every bidder.
- Check certificates and a sample tag register. Ask for documents, not promises.
- Interview the proposed supervisor. Not only the sales contact. Our supervisor interview questions help.
- Score the answers and record the decision. Keep the record for the audit.
Common mistakes on site
- Choosing on the lowest rate, then finding at the first inspection that nobody on the crew can sign a tag.
- Treating a card as proof of site-specific competence. The client decides which cards it accepts (see CISRS and CSCS in 2027).
- No agreed measurement rule, so every variation becomes an argument.
Questions
Does a UK card guarantee acceptance on a Gulf site?
No. Each client and main contractor decides which cards it accepts on its sites. Ask the site HSE team before you mobilise.
Who should check the contractor's scaffold design?
Someone other than the designer. See who can check a scaffold design.
Can I use this checklist as a contract document?
No. It is guidance for learning. Your contract and your client's rules govern.
Does AL-YASSIN take on contractor appraisal work?
AL-YASSIN is not taking paid work or payments at this time. The free contractor readiness check lets a contractor self-check against 25 points.
- NASC: SG39:21 Guidance on Appointing a Scaffolding Contractor (product page; the guidance is a UK document; verify against the latest edition)
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.