Home/Exams/Scaffold Design Engineer (BS EN 12811-1 and TG20)
Scaffold Design Engineer (BS EN 12811-1 and TG20) exam
Free, 50 questions in 50 minutes, open to everyone. Actions, wind and sheeting, load combinations, tube and beam design, couplers and joints, ties and anchorages, foundations, special structures, stability and BS 5975 procedures. Mostly calculations. Pass with 70% and get a certificate anyone can verify online.
Independent exam based on BS EN 12811-1, NASC TG20 Design Guide (TG20:13 used for this bank; check TG20:21) and BS 5975. Not issued or endorsed by any standards body or regulator. Questions in English; optional translation: العربية, اردو (draft).
What the exam covers
Each paper is drawn fresh from the bank across these 10 domains.
- Actions on scaffolds
- Wind actions and sheeting
- Load combinations and partial factors
- Member design: tubes, beams and boards
- Couplers, joints and connections
- Ties and anchorages
- Foundations and bearing
- Special structures
- Stability, imperfections and bracing forces
- Temporary works management (BS 5975)
How it works
- 1
Sit it in one go
50 questions, 50 minutes, on your phone or computer. Each question has its own time; no going back. Leaving the page is recorded; the third time ends the paper.
- 2
Register to see your score
Your name and email at the end. The score and the domain breakdown arrive free by email.
- 3
Pass at 70%
You get a certificate with a number and a QR code. Valid one year, renewed free by passing again.
- 4
Challenge a colleague
Every result comes with a challenge link. Exam starts from your link are counted to you; the top 3 each month get a free full review.
Sample questions
Three questions from the bank, with the answer, the working and the reference. The real paper has 50.
Q1A scaffold's tie plan shows 22 ties on one façade, of which 13 are reveal ties, each carrying 2.8 kN. Does the arrangement fall within TG20 guidance?
- Yes: reveal ties carry light-duty loads up to 3.5 kN, and 2.8 kN is below that
- No: 59 % of the ties are reveal ties, above the recommended 50 %, so at most 11 should be
- Yes: up to 60 % of ties may be reveal ties if they are checked weekly
- No: reveal ties may never carry more than 2.0 kN each
Answer: No: 59 % of the ties are reveal ties, above the recommended 50 %, so at most 11 should be. 13/22 = 59 %. TG20 recommends that no more than 50 % of the ties to a façade are reveal ties (at most 11 here), and that they are used only where light-duty ties suffice. Relying mainly on reveal ties needs careful consideration, a written procedure and defined responsibility for maintaining their tightness, since they depend on friction. NASC TG20:13 Design Guide, section 2.1.9.9 (verify against TG20:21).
Q2What design plastic moment resistance should be used for a 48.3 × 4.0 mm S235 tube (Wel = 5.70 × 10³ mm³, Wpl = 7.87 × 10³ mm³, D/t = 12.1) in a BS EN 12811-1 limit state check?
- 1.22 kN·m
- 1.34 kN·m
- 1.53 kN·m
- 1.68 kN·m
Answer: 1.68 kN·m. D/t = 12.1 is far below the class 1 limit for tubes (50ε² = 50 for S235), so the plastic modulus may be used: Mpl,d = 7.87 × 10³ × 235/1.1 = 1.68 kN·m (BS EN 12811-1 (9) is written in plastic moments). 1.22 kN·m uses Wel; 1.34 kN·m uses Wel without γM; 1.53 kN·m applies γM twice. BS EN 12811-1:2003, 10.3.2.2 and 10.3.3.2; NASC TG20:13 Design Guide 5.8.1 (verify against TG20:21).
Q3A TG20-compliant tower has a 2.7 m × 3.3 m base. What maximum heights do TG20's compliant designs allow when it is (i) internal and (ii) external under a wind management system?
- (i) 10.8 m; (ii) 8.0 m
- (i) 10.8 m; (ii) 8.1 m
- (i) 10.8 m; (ii) 10.8 m
- (i) 13.2 m; (ii) 9.9 m
Answer: (i) 10.8 m; (ii) 8.0 m. Internal: 4 × lesser base (4×2.7 = 10.8 m), not above 10.8 m, so 10.8 m. External: 3 × lesser base (3×2.7 = 8.1 m), not above 8.0 m, so 8.0 m. 8.1 m misses the cap; 13.2/9.9 m uses the larger base dimension. NASC TG20:13 Design Guide, sections 2.5.3 and 2.5.4 (verify against TG20:21).
Questions
Who can sit this exam?
Anyone. It is written for engineers who design or check scaffolds and temporary works to European and UK practice. There is no degree check; the certificate is issued when you pass in one timed sitting.
Is this an official BSI or NASC exam or card?
No. It is an independent AL-YASSIN exam based on BS EN 12811-1, NASC TG20 Design Guide (TG20:13 used for this bank; check TG20:21) and BS 5975. It is not issued, approved or endorsed by BSI, NASC or CISRS, and it does not replace any card or training your employer or the law requires.
How many questions, and how long?
50 questions in 50 minutes, one sitting, drawn fresh from a bank of 443 questions. Each question has its own time and you cannot go back. Pass 70%, merit 85%.
How hard is it?
Hard on purpose. Most questions are calculations or site scenarios where you must apply two or more rules; recall questions are few. Someone who only memorised numbers should not pass.
What language are the questions in?
English, with a translation line under every question and answer in the language you choose: العربية, اردو (draft). You can change the language during the paper. The English text is the one that is marked. Draft translations have not yet been checked by a native speaker.
What does it cost?
Sitting the exam, seeing your score and getting the certificate when you pass are free. A full review that shows every mistake with the right answer, the working and the reference costs USD 100 (15 days of access).
How long is the certificate valid?
One year. Renew it free by passing the exam again. Anyone can check a certificate by its number or QR code at alyassinscaffold.com/verify.