Common questions builders ask about scaffolding safety.
Who can inspect scaffolding?
Scaffolding inspections must be carried out by a competent person. Under the Work at Height Regulations 2005, a competent person is someone with sufficient training, experience, and knowledge to identify defects and assess whether the scaffold is safe to use. There is no single required qualification, but in practice most competent persons hold a CISRS Scaffolding Inspection Training Scheme (SITS) card or equivalent. The key point is that the person must genuinely understand scaffolding — they need to know what a properly erected scaffold looks like, what the common defects are, and what the relevant standards require. A general site manager who has never worked with scaffolding would not normally be considered competent to inspect it, even if they are experienced in other areas of construction. The person carrying out the inspection must also be sufficiently independent — they should not be under pressure to pass a scaffold that is not safe. On smaller sites, a competent scaffold erector or an experienced site manager with scaffold inspection training may carry out inspections. On larger projects, a dedicated scaffold coordinator or the scaffolding contractor’s own inspection team will usually handle it. Whoever does the inspection, the results must be recorded in writing and the report kept on site.
How often must scaffolding be inspected?
The Work at Height Regulations 2005, Schedule 7, set out the minimum inspection requirements for scaffolding. A scaffold must be inspected before it is first used after erection, after any substantial alteration, after any event likely to have affected its stability (such as high winds, heavy rain, or accidental impact), and at intervals not exceeding seven days. The seven-day rule is the one that catches most people out. It means that every scaffold on your site needs a formal inspection at least once a week, every week, for as long as it is standing. If a scaffold has been up for three months, that is at least twelve inspections you need to have recorded. Missing even one leaves you exposed — both legally and in terms of the safety of anyone working on or near the scaffold. Each inspection must be recorded in a scaffold inspection report. The report must include the date and time of the inspection, the location and description of the scaffold, the name of the person who carried out the inspection, and details of any defects found and the action taken. These reports must be kept on site and available for inspection by the HSE or the principal contractor.
Do I need a scaffold design?
It depends on the complexity of the scaffold. For standard configurations — a basic independent or birdcage scaffold that follows the dimensions and loading criteria set out in TG20 — a full bespoke design by a structural engineer is not required. Instead, the scaffolding contractor can produce a TG20 compliance sheet, which confirms that the scaffold conforms to the guidance and has been erected within the permitted parameters. The TG20 compliance sheet acts as the design document. However, if the scaffold falls outside the scope of TG20 — for example, if it is unusually tall, heavily loaded, has complex geometry, is free-standing, or is subject to unusual wind conditions — then a bespoke design by a competent engineer is required. The design must be specific to the scaffold being erected and must take into account the loads it will carry, the ground conditions, the wind exposure, and any ties to the building. In practice, most residential and small commercial scaffolds will be covered by TG20. Larger or more unusual scaffolds will need a bespoke design. If you are unsure, ask your scaffolding contractor whether the scaffold is within TG20 scope. If it is not, they should be providing a design drawing and calculations before they start erecting.
What is a TG20 compliance sheet?
TG20 stands for Technical Guidance Note 20, published by the National Access and Scaffolding Confederation (NASC). It provides detailed guidance on the design and erection of tube and fitting scaffolding. The TG20 compliance sheet is a document generated using the TG20 software tool, which confirms that a particular scaffold configuration — defined by its height, lift heights, bay lengths, number of boards, loading class, and tie pattern — complies with the TG20 guidance and does not require a bespoke design. The compliance sheet is scaffold-specific: it is generated for the actual dimensions and configuration of the scaffold being erected. It includes details of the permitted loading, the required tie pattern, the base plate and sole board requirements, and any other conditions that must be met. If the scaffold is erected in accordance with the compliance sheet, it is considered to have a valid design. The TG20 system was introduced to reduce the burden of commissioning full design drawings for straightforward scaffolds. Before TG20, even simple scaffolds technically needed a bespoke design, which was expensive and time-consuming. TG20 compliance sheets give scaffolding contractors a practical way to demonstrate compliance for standard configurations. However, the compliance sheet is only valid if the scaffold is actually erected to match the parameters in the sheet. If the scaffolders deviate from the specified configuration, the compliance sheet no longer applies.
Can I alter scaffolding myself?
No. Under the Work at Height Regulations 2005, scaffolding must only be erected, altered, or dismantled by competent persons who have received appropriate training for the complexity of the scaffold. For most tube and fitting scaffolds, this means CISRS-trained scaffolders. Altering a scaffold includes removing boards, moving guard rails, removing ties, adding loading bays, or changing the configuration in any way. Even seemingly minor changes — like removing a single board to get materials through, or unclipping a guard rail to access a window — can compromise the structural integrity of the scaffold and create a fall risk. If you need a scaffold altered, contact the scaffolding contractor and ask them to make the change. They will assess whether the alteration is safe, carry out the work using trained operatives, update the TG20 compliance sheet or design if necessary, and re-inspect the scaffold before handing it back for use. If you alter the scaffold yourself and someone is injured or killed as a result, you could face prosecution for breaching the Work at Height Regulations. The HSE takes unauthorised scaffold alterations very seriously. It is one of the most common causes of scaffold collapses and falls from height on construction sites. The rule is simple: if you are not a trained scaffolder, do not touch the scaffold.