In 10 seconds
A roofer must plan safe access (scaffold, harness, or platform) for any work where falling could injure them. For replacements above 25% of the roof, Building Control approval is required โ CompetentRoofer registration lets the contractor self-certify and bundles a 10-year insurance-backed guarantee.
The Work at Height Regulations 2005
The Work at Height Regulations 2005 (SI 2005/735) came into force on 6 April 2005 and apply across the UK including Wales. The critical scope is "any work where a person could fall a distance liable to cause personal injury" โ there is no minimum height threshold.
In practice for a Welsh homeowner: this covers all pitched-roof work, gutter cleaning, chimney repairs, lead flashing, and slate replacement. The Health and Safety Executive (HSE) enforces.
When scaffolding is required
There is no single legal threshold that says "scaffolding required above X metres". Instead, the duty is on the person controlling the work to choose the safest method.
In practice, the following typically require scaffolding rather than ladders alone:
- Pitched-roof work โ sloping roofs need scaffold edge protection to prevent slips at the eaves.
- Any roof more than ~2 metres above ground at the eaves.
- Multi-day jobs where lifting materials repeatedly via ladder is itself a fall risk.
- Work involving more than one person on the roof simultaneously.
NFRC membership โ what it signals
The National Federation of Roofing Contractors represents around 70% of the UK roofing industry by value. NFRC members are vetted through office and site audits and must demonstrate insurance, training, and best-practice compliance. Membership is voluntary, but it's the closest thing to a trade-body kitemark for roofing.
Verify any roofer at nfrc.co.uk/find-a-member โ search by location or contractor name.
CompetentRoofer โ when self-certification applies
CompetentRoofer (now the NFRC Competent Person Scheme) is a government-licensed scheme that lets registered roofers self-certify their work as Building Regulations compliant โ without separate Building Control approval.
It applies when 50% or more of the roof is being replaced. The registered contractor completes the work, NFRC notifies Building Control within 8 weeks, and you automatically receive both a Building Regulations Compliance Certificate AND a 10-year insurance-backed guarantee at no extra cost.
If your roofer ISN'T CompetentRoofer-registered and you're replacing more than 50% of the roof, they must obtain Building Control approval separately โ typically 4-6 weeks longer and ยฃ250-ยฃ500 in fees.
Welsh slate, lead, and chimney standards
Welsh slate is among the world's most durable roofing materials. The three main Welsh quarries โ Penrhyn, Ffestiniog, and Cwt-y-Bugail โ all produce slate guaranteed for 100 years.
Whatever the material, installation must comply with BS 5534 (Code of Practice for Slating and Tiling), which covers layout, fixings, underlays, and ventilation. Lead used for flashings, valleys, and roof junctions must meet BS EN 12588 โ Code 4 or 5 is standard for domestic work.
Chimney work falls under Welsh Approved Document J. Flashings at the chimney-roof intersection must be non-ferrous metal and properly detailed. Any chimney work beyond routine repair triggers Building Control approval.
The 25% rule for re-roofing
If you replace or repair less than 25% of the roof area, you typically don't need Building Regulations approval. Above 25%, or any change to fire performance / insulation, approval is required.
Practical tip: a single broken slate replacement doesn't need approval. A full re-slate of one elevation usually does.
Insurance โ what to demand from your roofer
UK law does not mandate roofer insurance, but every reputable contractor carries it. For Welsh domestic work, ask for proof of:
- Public liability insurance โ ยฃ2 million minimum, ยฃ5 million typical for domestic work.
- Employers' liability (if they have employees) โ legally required at ยฃ5 million minimum if they hire anyone.
- Tools and materials cover โ covers theft from site, often overlooked.
- For CompetentRoofer-registered contractors: the 10-year insurance-backed guarantee on the work itself.
Frequently asked questions
Does my roofer need scaffolding for a small repair?
It depends on the work and the roof. The legal duty is on the roofer to risk-assess and pick the safest method. For a single dislodged slate at the ridge of a two-storey roof, a ladder + roof ladder may be appropriate. For multi-day work or work near the eaves of a steep pitch, scaffolding is the safer (and often legally required) choice.
Is my roofer required to have insurance?
Public liability isn't legally mandatory but is the industry standard โ ยฃ2-ยฃ5 million for domestic work. Employers' liability IS legally required if they have any employees (ยฃ5 million minimum). Always ask for written proof before work starts.
How do I verify NFRC membership?
Search at nfrc.co.uk/find-a-member by contractor name or location. The result will show their member status and the regions they cover. Phone the NFRC directly on 020 7448 3858 if you can't find them on the register but they claim membership.
Is there a Welsh-specific roofing standard?
Welsh roofing follows the same UK Building Regulations as England โ Part L for thermal performance, Part J for chimneys, BS 5534 for slating and tiling, BS EN 12588 for lead. The Welsh-specific factor is that Welsh slate quarries set particularly high material standards, which doesn't change the installation standard but does affect material specification.
What happens if my roofer doesn't use CompetentRoofer?
For repairs under 25% of the roof, nothing โ no approval needed. For 50%+ replacement, your roofer must obtain Building Control approval from your local authority instead. That takes 4-6 weeks longer and adds ยฃ250-ยฃ500 in council fees, plus you don't get the 10-year insurance-backed guarantee that comes with CompetentRoofer.
What guarantees should my roofer provide?
For straightforward repairs: 1-2 year workmanship warranty plus manufacturer warranties on materials (slate, tiles). For full re-roofs by CompetentRoofer contractors: the 10-year insurance-backed guarantee is automatic. Always get the warranty in writing before paying.
Sources
- Work at Height Regulations 2005 โ Primary UK regulation on falling-risk work.
- HSE โ Working at Height โ Health and Safety Executive enforcement guidance.
- NFRC โ find a member โ Live register of National Federation of Roofing Contractors members.
- NFRC Competent Person Scheme (CompetentRoofer) โ Government-licensed self-certification scheme for major roof replacements.
- Welsh Government โ Roof building regulations โ Welsh-specific guidance for roof work.
- Welsh Government โ Flues and chimneys โ Approved Document J context for chimney work.
Find a verified roofer in Wales