Mineral wool EWI · Gwynedd
Mineral wool external wall insulation in Bangor (Gwynedd)
We quote mineral wool external wall insulation for homes in Bangor (Gwynedd, LL57) and nearby Llangefni and Caernarfon, with guide prices online and a free survey to fix the price. On blocks and taller buildings in Bangor (Gwynedd), mineral wool is the default because of the fire guidance for external walls.
- Free survey in LL57 and nearby
- Guide price from £125 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Bangor (Gwynedd)
Postcode, service and a phone number is all we need.
Included as standard
- Vapour-open, so moisture in solid walls can dry outwards
- Finished in mineral or silicone render, or brick slip
- Better sound reduction than foam boards
- Used on blocks of flats and buildings with storeys above 11m
Homes and walls in Bangor (Gwynedd)
Surveys in Bangor (Gwynedd) also cover the surrounding LL57 district and towns such as Llangefni and Caernarfon. North Wales has many solid stone and slate-built homes, Victorian seaside terraces and post-war council estates.
Parts of Gwynedd fall in the higher wind-driven rain exposure bands, especially coastal and upland sites, so render specification, movement joints and detailing at cills, verges and the base of the wall matter more than usual.
Older solid-walled homes in Bangor (Gwynedd) can suit a vapour-open mineral wool build-up better than foam; the survey checks the wall first.
- Postcode district
- LL57
- County or area
- Gwynedd
- Nation
- Wales
- Nearby
- Llangefni, Caernarfon, Llandudno, Colwyn Bay
Wales: planning and regulations
We check Bangor (Gwynedd) addresses for conservation areas and listing before quoting, because Welsh permitted development rules don't cover every external change.
Welsh Building Regulations expect walls to be upgraded when a substantial area is renewed, and building control signs the work off.
Wales applies its own external wall fire rules, updated in 2025; on taller residential buildings we specify non-combustible mineral wool systems.
Why choose mineral wool over EPS?
Two reasons come up most: fire and moisture. Mineral wool doesn't burn, which is why guidance for taller residential buildings points to non-combustible external wall materials. It is also vapour-open, so a solid wall that holds some moisture can keep drying outwards through the insulation and render.
The trade-offs are weight and cost. Slabs are denser, need more fixings and take longer to install, so the price per m² is higher than EPS.
Mineral wool external wall insulation prices in Bangor (Gwynedd)
| Item | Guide price | Notes |
|---|---|---|
| Mineral wool + mineral or silicone render | £125–£170 per m²0% VAT | Excluding scaffold |
| Mineral wool + brick slip | £195–£260 per m²0% VAT | Heavier slip systems need extra fixings |
| Three-bed semi, full house | £11,800–£20,2000% VAT | 80–100 m² of wall, including scaffold |
Confirmed by a fixed written quote after survey. 0% VAT: installing insulation in a home is zero-rated until 31 March 2027, so these figures are the total; 5% applies from 1 April 2027.
How it works
Enquiry
Send your postcode and a few details.
Measured survey
Walls, damp, eaves, cills and services recorded.
Written price
A fixed price with the specification attached.
Work and handover
Installed, inspected and documents handed over.
Mineral wool EWI in Bangor (Gwynedd): questions
Can mineral wool EWI have a brick finish?
Yes. Brick slips can be bonded over mineral wool systems designed for them, with additional fixings for the extra weight.
Is mineral wool better than EPS?
Not always better — different. Mineral wool wins on fire performance, breathability and acoustics; EPS wins on cost, weight and thinner boards for the same U-value. The wall, the building height and your priorities decide it.
Does mineral wool get wet?
It is water-repellent and protected by the render system. Like any insulation it must not be left exposed to rain during installation, so boards are covered and work stops in wet weather.
Do you cover Bangor (Gwynedd)?
Yes — we survey and quote mineral wool external wall insulation in Bangor (Gwynedd, LL57) and nearby Llangefni, Caernarfon and Llandudno, with a fixed written price before any work starts.