Duratite installs three distinct Gaco coating systems on asbestos cement roofs: GacoFlex S42 silicone, Gaco 127 acrylic, and GacoFlex U92 urethane. They all waterproof a roof — but they are not interchangeable, and picking the wrong one can cost you years of service life. This article explains the differences in plain terms, shows where each system wins, and ends with a decision framework you can apply to any commercial building.
Why the System Choice Matters
The three systems have different chemistry, different warranty periods, different price points, and different best-use cases. A chilled warehouse in Cork with a clean AC roof does not need the same specification as a heavy manufacturing plant in Belfast with constant maintenance traffic. Matching the system to the building is what keeps the cost-per-year-of-protection as low as possible.
GacoFlex S42 — Silicone
S42 is the long-life workhorse. A 100% silicone, fibre-reinforced liquid applied membrane, fully manufacturer-documented, with a 20-year warranty when installed by an approved contractor. It cures to a seamless weatherproof skin that handles ponding water, UV exposure and thermal cycling without cracking.
Strengths
Unmatched UV stability, excellent elongation, zero VOC, silicone chemistry never gets brittle, fibre reinforcement means no separate mesh layer, fastest cure of the three systems in most weather conditions.
Weaknesses
Highest upfront cost per m². Slightly lower abrasion resistance than urethane — so not ideal where roof is walked on daily.
Gaco 127 — Acrylic
Gaco 127 is a water-based acrylic designed for cost-sensitive projects where the budget does not stretch to a full silicone system. It comes with a 10-year warranty and is perfect for buildings that are due to be redeveloped, sold or demolished within that timeframe.
Strengths
Lowest installed cost of the three systems, easy application, fast-drying, low odour, very forgiving on the substrate. Ideal for interim fixes.
Weaknesses
Shorter warranty than S42 or U92. Less tolerant of ponding water long-term. More sensitive to cold weather application windows.
GacoFlex U92 — Urethane
U92 is a two-pack polyurethane system designed for industrial environments where the roof takes regular foot traffic, tool drops, or chemical exposure. It comes with a 15-year warranty and offers the best abrasion resistance of the three systems.
Strengths
Exceptional abrasion and chemical resistance, good UV performance, strong mechanical properties, good choice for plant-heavy roofs and processing facilities.
Weaknesses
Two-pack system means stricter mixing discipline and a shorter pot life. Higher cost than 127. Slightly longer application window than S42 in cooler weather.
Get Free Advice or Book a Survey
Duratite's technical team provides free site assessments and fixed-price quotations across Ireland and Northern Ireland. No obligation.
Head-to-Head Comparison
| Feature | GacoFlex S42 | Gaco 127 | GacoFlex U92 |
|---|---|---|---|
| Chemistry | Silicone, fibre-reinforced | Acrylic, water-based | 2K polyurethane |
| Warranty | 20 years | 10 years | 15 years |
| Relative upfront cost | Mid-to-high | Lowest | Highest |
| UV resistance | Excellent | Good | Very good |
| Abrasion resistance | Good | Moderate | Excellent |
| Ponding water | Excellent | Limited | Very good |
| Best for | Long-life commercial | Budget / interim | Industrial / traffic |
How to Choose
Duratite will recommend the right system at survey stage based on roof condition, building use, and your organisation's capital plan. There is no single right answer for every building — only the right answer for yours. See the full cost breakdown for what drives the price.
Typical Specifications
Three typical specification scenarios:
Logistics depot, 3,500 m²: GacoFlex S42, 20-year warranty. Reason — 30-year asset hold, long-life required.
Agricultural store, 800 m²: Gaco 127, 10-year warranty. Reason — building scheduled for replacement in 2035.
Chemical plant, 1,200 m²: GacoFlex U92, 15-year warranty. Reason — chemical exposure and daily engineer access.