- Guide price
- £12,150–£20,050
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Gwynedd at a glance
- Largest towns
- Bangor, Gwynedd, Caernarfon
- Postcode areas
- LL
- Building control
- Gwynedd Council
- Neighbouring areas
- Isle of Anglesey · Conwy · Denbighshire · Flintshire
- Guide price region
- Wales (−8% on West Midlands rates)
How much does a commercial flat roof cost in Gwynedd?
Guide prices including VAT at Wales rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Commercial roof (100 m²), single-ply + insulation | £12,150–£20,050 |
| Condition survey and leak investigation | £140–£280 |
| Block of flats (150 m²), felt + insulation + scaffold | £14,300–£25,000 |
Which flat roofs are common in Gwynedd?
Flat roofs in Gwynedd sit on bungalows with flat-roofed side extensions and dormers, 1960s and 1970s link-detached houses with flat-roofed garages and porches and 1930s semis with flat-roofed garages and kitchen extensions. Wales averages roughly 1,460 mm of rain a year, among the wettest in Britain, so we design for steady run-off: proper falls, clear outlets and upstands well above the finished roof. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in Wales
Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. Renovated roofs are upgraded to around 0.16 W/m²K where feasible, and new extension roofs are built to 0.13 W/m²K under the Welsh Approved Document L. In Gwynedd the application goes to Gwynedd Council. More on the rules.
How do you handle CDM, roof access and fragile surfaces?
Every job is planned under the Construction (Design and Management) Regulations 2015, or CDM (NI) 2016 in Northern Ireland, with a construction phase plan and a method statement for the roof.
As a commercial client you have duties under CDM too, including passing on information about the building, such as drawings, details of previous roof work and the asbestos register. Buildings put up before 2000 can contain asbestos, so we ask for the register or a refurbishment survey before pricing a strip-out. If asbestos is found, a licensed specialist surveys and removes it before we start.
Roofs and rooflights are treated as fragile until a competent person confirms otherwise. Edge protection goes up on every job, rooflights and fragile sheets are covered or fenced off, and we agree safe access before work starts: scaffold, a tower, a powered access platform or a fixed access point where one is suitable.
Can you work around our trading hours and site rules?
Yes. Most commercial roofs can be replaced while the building stays open, and we agree the programme with you before any work starts.
That normally means set working hours, delivery and skip positions that keep entrances and fire exits clear, and phasing the roof so each section is watertight before the team leaves site. Noisy tasks such as strip-out can be timed for quieter periods, and early starts or weekend working can be arranged where your site allows. We tell you in advance which areas below the roof may be affected, so stock and equipment can be protected or moved.
Where torch-on felt is specified, the team works under your hot works permit system, with a fire watch after the torch is put away. If your site does not allow naked flames, we specify a cold-applied, self-adhesive or other flame-free system instead. Tenants, alarm companies and mechanical contractors are coordinated through one named contact.
Which towns in Gwynedd do we cover?
Commercial flat roofing in Gwynedd: questions
Which towns in Gwynedd do you cover?
All of Gwynedd. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a commercial flat roof cost in Gwynedd?
£12,150–£20,050 for a 100 m² commercial roof in single-ply with insulation, at Wales guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in Gwynedd?
It depends on where the roof is: in Gwynedd that's Gwynedd Council. Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. We confirm which applies at the survey.
Do you need a hot works permit?
Only if torch-on felt or other naked-flame work is used, in which case the team works under your permit system with a fire watch afterwards. Where hot works are not allowed, we specify a flame-free system such as a cold-applied membrane.
Can you re-roof while our premises stay open?
Usually, yes. We phase the work so each section is watertight before the team leaves site, keep entrances and fire exits clear, and agree working hours and deliveries with you first.
Can our existing roof be overlaid instead of stripped?
Often, if the survey shows the existing covering is sound, dry and firmly bonded. Wet insulation, a soft deck or several old layers mean a strip-out is the better long-term answer.
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