Temporary roofs and scaffold roofs during a commercial re-roof
Updated 23 October 2026 · SEO Dons Editorial
What is a temporary roof or scaffold roof?
A temporary roof is a designed structure, usually built from scaffold components and sheeted, that keeps weather off the building while the permanent roof covering is stripped and replaced. NASC, the scaffolding trade body, describes its guide TG09:18 as setting out "best practice for the planning, design, erection, and dismantling of temporary roofs and enclosed scaffold structures, with particular focus on loadings, weather effects, structural stability, and safe sequencing of works".
HSE puts temporary works in context: they "provide an engineered solution that is used to support or protect either a structure during construction, an item of plant or equipment, the sides of an excavation during construction operations or to provide access". A temporary roof is therefore not a tarpaulin. It is a structure with loads, supports and an inspection regime. Emergency covers after a leak or storm are a different subject, covered in what to do after a commercial roof leak.
When does a commercial re-roof need one?
No rule says a re-roof must have a temporary roof. It is a risk decision, and the usual questions are what sits under the roof, how long the roof will be open, and who is working or trading below. The factors that push towards a temporary roof include:
- stock, equipment, processes or finishes underneath that a single wet day could damage, including heritage interiors;
- a building that stays occupied during the works;
- a roof too large to strip and make watertight again within the weather windows the programme allows;
- a phased or long programme that runs into a wet season.
The alternative is phased weathering-in: the roof is stripped and closed in sections small enough to be made watertight at the end of each period of work, so only a limited area is ever open. The table compares the two.
| Question | Temporary roof | Phased weathering-in |
|---|---|---|
| Where does the weather risk sit? | With the structure: its design, wind and snow loads, and inspection | With the forecast, the size of each open section and the temporary seals |
| What does it add to the programme? | Design, erection and dismantling stages before and after the roofing | Smaller work packages and more sealing at each stop |
| What does the client need to supply? | Building information, access, and how long the cover must stay up | Agreed limits on open area and an approach to stopping work in bad weather |
| Where does it fit best? | Vulnerable interiors, occupied buildings, long programmes | Smaller roofs and robust interiors |
Neither route removes the need for a method statement. HSE calls it "the common way to help manage work on roofs and communicate the precautions to those involved". The wider choice between repair, overlay and strip-and-recover is in the repair or replace guide.
What does a temporary roof involve?
Design. HSE lists "temporary roofs and temporary buildings" among scaffold structures that normally need a bespoke design, and says that unless a scaffold follows a generally recognised standard configuration, "the scaffold must be designed by bespoke calculation, and by a competent person". The law, per HSE, is that any temporary structure "must be designed, installed and maintained to withstand any foreseeable loads which may be imposed on it".
Information. HSE says the user "must supply relevant information to the scaffold contractor" at the start of planning, including the period the scaffold must stay in place, "whether there is a requirement for sheeting, netting or brickguards", and "information on the structure/building the scaffold will be erected against". Sheeting changes the loads: "Never sheet or attach debris netting to a scaffold without informing those involved in the design and erection of the structure". Wind exposure varies by site, which is why the UK wind map and uplift guide is worth reading beside the design brief.
Inspection. HSE says scaffolding should be inspected after installation and before first use, "at an interval of no more than every 7 days thereafter", and "following any circumstances liable to jeopardise the safety of the installation eg high winds".
Management. HSE notes that "There are no specific legal requirements about how temporary works should be managed". It describes appointing a Temporary Works Coordinator as "an effective way of managing temporary works", and lists BS 5975-1:2024 as the related code of practice.
Who is responsible for designing and controlling it?
The Construction (Design and Management) Regulations 2015 define a "structure" to include "any formwork, falsework, scaffold or other structure designed or used to provide support or means of access during construction work". Whoever designs it is therefore a designer, and regulation 9 requires a designer to "take into account the general principles of prevention and any pre-construction information to eliminate, so far as is reasonably practicable, foreseeable risks to the health or safety of any person". The client's role and the construction phase plan are explained in who writes the construction phase plan for a re-roof.
On control, HSE says that "On a complex project this person is often a chartered civil or structural engineer", while "On a simpler job the main contractor may take on this role and seek advice as needed from an engineer". Its FAQ adds that "The legal requirement is that the party in control must ensure that work is allocated and carried out in a manner that does not create unacceptable risk of harm to workers or members of the public". Contractors on business premises "should work closely with the client and agree arrangements for managing the work".
Do licences or permissions apply?
If any part of the scaffold is on or over a public highway, yes. Section 169 of the Highways Act 1980 says no person shall, in connection with the alteration, repair or maintenance of any building, "erect or retain on or over a highway any scaffolding or other structure which obstructs the highway" without a licence from the highway authority. HSE adds that scaffolds which encroach over the highway, including pavements, require such a licence from the local highway authority. Other consents, for example on a listed building or in a conservation area, should be raised with the local planning authority early.
How does the choice change programme and risk?
A temporary roof adds design and erection time before roofing starts and dismantling after it, but it separates the roofing from the weather. Phased weathering-in keeps the programme shorter and the structure simpler, and puts the risk on forecasting and sealing at the end of each shift. Questions worth putting to a contractor before choosing:
- Is the temporary roof designed, by whom, and to what wind and snow loads?
- Who is the temporary works coordinator, and who inspects it, how often and after what weather?
- What does the design assume about the structure it bears on or ties to?
- For phased work, what is the largest area open at one time, and how is each section sealed at the end of the shift?
- Does the programme show erection, inspection and dismantling, and who pays for weather delay?
- Is a highway licence needed?
A building owner who wants these questions answered for a particular roof can send an enquiry through the form on this site. The project stages are set out in how a commercial flat roofing project works.
Sources
- Scaffolds, Temporary works, Temporary works FAQs and Roof work, HSE, checked 22 October 2026.
- TG09:18 Guide to the Design and Construction of Temporary Roofs and Buildings, National Access and Scaffolding Confederation, checked 22 October 2026.
- Construction (Design and Management) Regulations 2015, regulation 2 and regulation 9, legislation.gov.uk, checked 22 October 2026.
- Highways Act 1980, section 169, legislation.gov.uk, checked 22 October 2026.
Common questions
Is a scaffold roof just sheeting fixed to a scaffold?
No. Sheeting changes the loads on a scaffold, and HSE says never to sheet or net one without telling those who designed and erected it, because the design must allow for it. A temporary roof is a designed structure, not an add-on to an access scaffold.
How often must a temporary roof be inspected?
HSE says scaffolding should be inspected after installation and before first use, then at intervals of no more than every 7 days, and after any circumstances liable to jeopardise its safety, such as high winds. The inspector must be competent for the type and complexity of the structure.
Is a temporary works coordinator a legal requirement?
Not by title. HSE says there are no specific legal requirements about how temporary works should be managed, and that appointing a coordinator is an effective way to do it. The legal duty is that the party in control must not create unacceptable risk of harm to workers or the public.
Who supplies the information the designer needs?
HSE says the user must supply it at the start of planning. That includes how long the structure will stay up, any sheeting, the loads it must carry, and details of the building it bears on or ties to. Building owners usually hold the drawings, so ask for them early.