The short answer
The principal contractor is the contractor a client appoints in writing to run the construction phase when more than one contractor is, or may be, working on the project. That is regulation 5 of the CDM Regulations 2015. A sole contractor holds no such title, yet is still expected to put a construction phase plan on paper.
On a roof job the title depends on how many firms will be on site. A roofer working alone is a contractor. Add a scaffold firm or a specialist for the rooflights, and an appointment may be due.
The role and where it comes from
CDM stands for the Construction (Design and Management) Regulations 2015. They say who is responsible for health and safety on a building project, from the client down to the people carrying out the work. A contractor is anyone who does construction work, which takes in the roofer, the scaffold crew and an electrician wiring a rooflight sensor.
When must a principal contractor be appointed?
Regulation 5(1) is the trigger. Once a project has several contractors, or several are reasonably likely at any stage, the client must put two appointments in writing: a designer to coordinate the planning stage and a contractor to run the site. The test counts firms, not the size of the job or its price. A modest re-roof with a separate scaffold firm can meet it.
The appointment is the client's duty. On a commercial roof the client is the business having the work done, often the owner, or the tenant who carries the repair duty under the lease. Read the lease early to see which of them that is, since the signature on the appointment has to be the right one.
What the principal contractor does
Regulation 12(1) gives the principal contractor the job of preparing the construction phase plan. That document records how the work will be run safely: site rules, access to the roof, edge protection, falls, fragile surfaces, the arrangements for other trades and for the public, and the way the site is kept tidy.
Is the plan needed on a one-contractor job?
Yes. Regulation 15(5) hands the same task to a sole contractor, who has to produce a plan of their own. So the plan exists on every project. What changes with the number of firms is the set of extra appointments and duties, not the plan itself.
On a roof the plan has real content. Roofs on older industrial buildings may be fragile, and HSE says asbestos cement roofs always are, so the plan should record how people will reach the roof and how sheets and waste will be handled. See asbestos cement roofs and fragility for the hazard behind that line. A short plan that names the real risks is worth more than a long one lifted from a template, and the people on the roof should be able to say where the plan is kept and what it tells them to do.
Domestic clients and commercial clients
The rules shift depending on who is paying. HSE's domestic client is a private person whose house, or a family member's house, is being worked on, with no business behind it. For those clients, regulation 7(1) moves the duties onto a lone contractor, or onto the principal contractor when the job has several. A business owner gets no such transfer.
Does that apply to commercial premises?
No. A trading business sits outside the domestic category, so whoever owns the shop, the workshop or the barn holds the client duties directly, with nobody to hand them to. A landlord who lets on a repairing lease may have passed the upkeep to the tenant, but the CDM client is the person for whom the project is carried out, so make sure the right party signs.
If you are unsure which category you fall into, ask your own adviser or read HSE's CDM pages. We do not give legal advice, but we can explain what the roofing project looks like on the ground and who will be on site, which is usually what the adviser needs to know.
Settling the roles before the start date
Decide the roles early, and write down who holds each one. The client makes the appointments, they are put in writing, and the construction phase plan exists before the site is set up. Leaving it to the week the scaffold arrives is the common failure, and it forces people to sign things they have not read.
Can the roofer be the principal contractor?
Yes, where the roofer is managing the other trades on the project, for example the scaffold hire and any electrical work, and the client agrees in writing. In other cases the client, a main contractor or a project manager holds the role. At survey we tell you which arrangement we expect, so you know the plan before work starts.
The same early conversation covers the scaffold licence, building control and the timetable, and our page on planning a commercial re-roof puts them in order. The wider service is described under commercial roofing. To begin, send the building address and a note of who else will be on site.
Roles on a roof project
What is a principal designer on a roof job?
Under regulation 5, the principal designer is appointed alongside the principal contractor when there is more than one contractor. The role covers planning and coordinating the design stage. On a simple re-roof the client may need advice on who is suited to hold it, and the appointment is still made in writing.
Does a one-day repair need a written plan?
The regulations give short jobs no exemption from the construction phase plan, and the single contractor draws one up before climbing the ladder. For a small repair it can be brief and in proportion, covering access, edge protection and fragile surfaces, but it is written down before the work begins.
The full picture: Commercial roofing in Taunton ยท More short answers