“How much does silicone roof coating cost per m²?” is the first question every specifier asks. The honest answer for Ireland and Northern Ireland is that every roof is priced per project — so rather than publish “from” rates that won’t match your roof, this guide explains exactly what drives the price, for both supply-only and fully installed work.
The short answer
- Supply-only silicone material: priced on the roof area, substrate and the system build-up needed
- Fully installed, 15-year warranty: a fixed quote after a free site survey
- Fully installed, 20-year premium warranty: a fixed quote after a free site survey, reflecting the additional inspection regime
In every case a silicone overcoat is typically a fraction of the cost of full strip-and-replace, because the existing roof stays in place. Projects at either extreme of size or complexity will be priced to match.
What drives the rate up or down
- Roof size. Economies of scale kick in around 1,000 m². Below 300 m², fixed access and mobilisation costs make the rate per m² noticeably higher.
- Substrate. Clean EPDM, TPO, metal and concrete — standard. Asphalt/BUR/felt needs a bleed-trap primer, which adds cost. Asbestos cement adds survey, risk-assessment and controlled-work costs.
- Access. A simple single-storey roof is the baseline. Scaffold, MEWP access, or edge protection on occupied buildings each add cost.
- Detailing complexity. Simple flat roof with few penetrations — standard. Heavily detailed with rooflights, plant decks, upstands — more detail work and more cost.
- Programme. Standard daytime access — standard rate. Out-of-hours, weekend and shutdown working carry a premium.
- Warranty tier. 10-year material only is supply-only. 15-year system adds standard labour. 20-year premium adds the triple-inspection regime.
What you get at each tier
| Tier | How it’s priced | Includes |
|---|---|---|
| Supply only — topcoat | Per project, on area | GacoFlex S42 material only, standard DFT |
| Supply only — full system | Per project, on area and details | S42 topcoat + SF42 detailing + bleed-trap if needed |
| Fully installed — 15-yr warranty | Fixed quote after survey | Material + labour + access + single mid-install inspection |
| Fully installed — 20-yr warranty | Fixed quote after survey | Material + labour + access + triple-inspection regime + premium warranty cover |
Comparison against other chemistries
| Chemistry | Relative installed cost |
|---|---|
| Acrylic (Cromapol, Acrypol) | Lowest upfront — but recoats every 5–8 years |
| Silicone (GacoFlex S42) | Low to mid — single coat, direct overcoat |
| Polyurethane (Polyroof, Kemperol) | Higher — three-layer reinforced build |
| PMMA (Triflex, Bauder LiquiTEC) | Higher still — multi-layer reinforced build |
| GRP (new build) | Mid — needs a sound timber deck |
| Single-ply strip-and-replace (EPDM/TPO) | High — strip-out, disposal and new membrane |
Why silicone is the cost-efficient choice for commercial
Silicone’s single-coat application, direct overcoat capability (no strip required) and long warranty interval together produce the lowest 20-year lifecycle cost per m² of any legitimate commercial roofing option. On a 2,000 m² warehouse refurbishment, the silicone route typically saves a substantial sum over the PU or strip-and-replace route — and a fixed quote after survey shows you exactly how much on your roof.
Want a firm written quote on your roof? Send size, substrate and Eircode or postcode to info@duratite.ie. Free survey, 48-hour turnaround.