A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
We handle a new flat roof as a managed project across Gwynedd: one contract, one contact, and trades working to an agreed specification. Coverage includes Bangor, Gwynedd, Llandudno, Holyhead and Caernarfon and their surroundings. In Wales the consent rules have their own details, which we check for you. Typical prices in Wales fall within £1,850–£4,100, VAT included, and are fixed in writing after a survey.
- Guide price
- £1,850–£4,100 inc VAT
- Time on site
- 1–3 days for most roofs
- Planning rules
- Wales
- Price level
- About 8% below the national guide
- Towns listed
- 4
- Survey
- Free, with a written quote
Flat roofs prices in Gwynedd
Prices for a new flat roof vary from house to house, but in Gwynedd most projects fall within £1,850–£4,100 including VAT. That reflects costs in Wales, about 8% below the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in Gwynedd |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £750–£1,850 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £1,850–£4,100 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £3,700–£8,300 |
Your price depends mostly on:
- Roof area and access to the roof
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
- Number of rooflights, pipes and upstands to detail
Scope of the work
- Survey of the covering, deck, falls, upstands and drainage
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- New EPDM, GRP or torch-on felt membrane laid to falls
- New trims, outlets and gutter connections
- Rooflights refitted or replaced where required
Homes in Gwynedd
Slate defines much of Gwynedd, from quarrying villages such as Bethesda and Blaenau Ffestiniog with their stone terraces to slate roofs across the county. Bangor and Caernarfon have Victorian and Georgian streets, Anglesey has stone cottages and bungalows, and resorts such as Pwllheli and Barmouth have Victorian terraces and newer bungalows.
Stone and slate homes need breathable lime render and pointing, and slate roofs often need careful repair rather than replacement. Terraces suit loft conversions, and bungalows commonly take extensions and window upgrades.
Eryri (Snowdonia) is among the wettest areas in the UK, and exposed coasts take strong wind and salt, so render and roof details need to be robust.
Do you need permission in Gwynedd?
For anyone in Gwynedd, the relevant framework is Wales's. The summary below is general, so we always contact the council about your address before putting a price in writing.
Re-roofing with similar materials does not usually need planning permission in Wales, except on listed buildings or where a conservation area restricts materials.
Building Regulations in Wales apply to major re-roofing, including insulation upgrades. Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Free site survey
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a new flat roof, and photograph or measure anything the quote needs to reflect.
Price and scope agreed
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Plan and prepare
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
On site to finish
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Questions about a new flat roof in Gwynedd
How long will a new flat roof take?
On a typical home, allow 1–3 days for most roofs. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Which is better, EPDM rubber or GRP fibreglass?
EPDM rubber and GRP fibreglass are both reliable modern flat roof systems. EPDM is a single flexible sheet with very few joints, which copes well with movement and suits most extensions and garages. GRP is a hard, seamless finish that copes better with foot traffic and complex shapes, but needs dry weather to apply. Felt costs less but usually lasts less long. We recommend a system after seeing your roof.
Do I need planning permission in Gwynedd?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Gwynedd is in Wales, so Wales's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
How long does a flat roof replacement take?
Replacing a typical extension or garage flat roof usually takes one to three days. Stripping and any deck repairs come first, then insulation where agreed, the new membrane and the trims and outlets. GRP needs dry weather and time to cure, and we plan around the forecast. Larger roofs or roofs with many rooflights take longer. We confirm timing with your quote.
Is a flat roof suitable for a roof terrace?
A flat roof can only be used as a terrace if it is designed for it, with joists strong enough for people and furniture, a hard-wearing surface, safe edge protection and correct drainage. Using a standard extension roof as a terrace can damage it and may need planning permission and building regulations approval. We can advise on what a conversion would involve.
Towns in Gwynedd
Find your town below. Every place listed in Gwynedd is covered for a new flat roof, with the same survey, written quote and fixed-price process.

