Roof & floor coatings · an Amrize brandGaco roof & floor coatings, supplied across Ireland and Northern Ireland
Gaco is a US coatings manufacturer owned by Amrize, known for 100% silicone roof systems that survive ponding water and UV without cracking or chalking. Duratite supplies GacoFlex in Ireland — holding stock, writing the specifications, and administering the manufacturer-backed warranty.
Four chemistries, one brand
What a Gaco coating actually does
Corroding metal and tired felt don't have to mean a tear-off. The roof stays where it is, the building stays open, and the coating does the work.
Seams detailed
AfterTresidder Close, Units 1–5, Falmouth — profiled metal, coated in place
687 m² of tired profiled metal over five occupied units. Seams, laps and fixings were detail-banded in silicone first, then the full GacoFlex S42 system went over the top. No sheets stripped, no unit closed.
Treveth Holdings LLP · installed by Gwella Contracting Solutions Ltd · Falmouth, England
Before
AfterTorquay flat roof — black and tired to seamless
A large flat roof at the end of its life, coated in place around every rooflight, upstand and plant unit. The building stayed in use throughout. Read the case study →
Duratite project, England
Before
AfterBournemouth roof terrace — seamless, and staying that way
An ageing domestic flat roof over living space, coated in place around the rooflight and every upstand. No tear-off, no skip, no disruption to the rooms below.
Duratite project, EnglandWho Gaco are — and what Duratite supplies in Ireland
Gaco built its reputation in the United States on 100% silicone roof coatings: single-component, moisture-curing, solvent-free systems that stay flexible under UV and tolerate standing water. The brand is manufactured by Amrize.
The range has since widened well past silicone — acrylic coatings for pitched metal, cold-applied urethanes for decks and walkways, epoxy primers and anti-slip floor systems, plus the ancillaries that make a specification work: bleed-trap base coats, seam reinforcement, repair compounds and roof wash.
Duratite supplies GacoFlex in Ireland. Delivery is across Ireland, with the lead time confirmed when you order, and the technical work that sits around the product is ours.
Duratite Building Products supplies the materials, the specification and the warranty administration. Application is by our network of approved contractors — or by your own team, once we've signed them off on the system.
Free site survey
Roof condition, substrate, adhesion test, moisture and detailing risks — before anyone quotes a number.
Written specification & take-off
Product, coats, dry film thickness, primer where needed, quantities and installed price. Free of charge.
Delivery across Ireland
Delivery across Ireland — lead time confirmed when you order, so your programme is planned around a real date.
QA pack & warranty
Wet-film records, photo log, environmental log and batch numbers — the evidence the warranty is issued against.
GacoFlex S42 — third-party approvals
Four chemistries — which one fits your roof
Most enquiries land on silicone, but it isn't always the right answer. Ponding, slope, foot traffic and substrate decide it. If you're not sure, send us photos and we'll tell you straight.
Silicone
The flagship. 100% silicone, moisture-curing, and the only family here rated to sit under ponding water without breaking down. Needs no primer over most substrates.
- GacoFlex S42 — two-coat system, up to 20-year warranty
- GacoFlex SF42 — fibre-reinforced grade, no separate fleece
- GacoPatch, Gaco Wash, A4271 Bleed Trap ancillaries
- Cool roof: 0.87 initial solar reflectance, SRI 110
Acrylic
Water-based elastomeric acrylic. Lower cost per square metre than silicone and a sound choice on pitched commercial and industrial metal — provided the roof drains and doesn't pond.
- GacoFlex 127 Series — two-coat, white finish
- Warranty term confirmed per project on specification
- Best on pitched profiled metal and box-profile roofs
- Not for roofs that hold water — specify silicone instead
Urethane
Cold-applied polyurethane for anywhere people actually walk: balconies, walkways, plant rooms, podium decks. Higher abrasion and chemical resistance than silicone.
- GacoFlex U91 — single-component base coat
- GacoFlex U92 — aliphatic urethane top coat
- GacoFlex H.E.R. — polyurethane roof sealant
- Specify where foot traffic is regular, not occasional
GacoFlex S42 — the reason most people call us
S42 is a 100% silicone, solvent-free, single-component coating that cures with atmospheric moisture. It is highly UV-stable and, unlike acrylic, it does not soften or wash away where water sits after a storm.
It bonds directly to most substrates with no primer — weathered asbestos cement, metal, aged bitumen, aged single-ply and existing silicone. Concrete takes an epoxy primer/sealer; asphalt and SBS take the A4271 Bleed Trap base coat.
S42 is not fibre-reinforced — SF42 is. Where a reinforced grade is specified, SF42's fibre is built in, so there's no separate fleece to lay.
| Solids by volume | 95% (ASTM D2697) |
|---|---|
| Tensile strength | 275 psi / 1.9 MPa |
| Elongation at break | 196% @ 73°F |
| Water swelling | 0% (ASTM D471) |
| Solar reflectance | 0.87 initial / 0.69 at 3 yr |
| Solar Reflectance Index | 110 initial / 84 at 3 yr |
| Min. DFT per coat | 18 mils / 0.45 mm |
| VOC | < 50 g/L |
| Colours | White, Grey, Tan, Dark Grey |
Gaco going down, start to finish
Real roofs, in the order the work actually happens — wash down, detail the seams, base coat, top coat, done. Click any photo to enlarge.
1 · Prep
2 · Bleed trap
3 · Seams
3 · Seams
4 · Coat
4 · Coat
5 · Done
5 · Done 5 · Done 5 · Done
5 · Done
5 · Done
Every Gaco product we stock
Trade supply, nationwide delivery, and a technical team who will tell you if you're buying the wrong thing. Prices and pack sizes are on each product page.
Silicone & acrylic roof systems
GacoFlex S42 Silicone Roof Coating
The flagship two-coat silicone system. White, Grey and Clear. Up to 20-year manufacturer-backed warranty.
View product →
GacoFlex SF42 Fibre-Reinforced Silicone
The reinforced grade — fibre is built into the product, so seams and details need no separate fleece.
View product →
GacoPatch Silicone Waterproofing Compound
Trowel-applied fibre-reinforced silicone for cracks, lap seams, fixings and penetration details before coating.
View product →
GacoRoof Silicone Roof Coating — 3.8 L
Small-pack silicone for smaller roofs, repairs and touch-in work where a full pail isn't warranted.
View product →
GacoFlex A4271 Bleed Trap™ Base Coat
Blocks bleed from asphalt and bituminous substrates. Required for warranted applications over SBS.
View product →
GacoFlex Roof Waterproofing Liquid Tape
Reinforcement at laps, joints and transitions where you want mechanical reinforcement in the detail.
View product →
Gaco Wash Roof Cleaning Solution
Substrate preparation. Adhesion depends on a clean, stable surface — this is not the step to skip.
View product →
GacoFlex 127 Series Acrylic Coating
Water-based elastomeric acrylic, two-coat. For pitched roofs that drain freely and don't pond.
View product →Urethane & sealants
GacoFlex U91 Urethane Base Coat
Single-component moisture-curing polyurethane for traffic-bearing decks, balconies and walkways.
View product →
GacoFlex U92 Aliphatic Urethane Top Coat
UV-stable aliphatic top coat over U91. Plant rooms, walkways, industrial decks and podium structures.
View product →
GacoFlex H.E.R. Polyurethane Sealant
High-elongation roof sealant for movement joints and demanding detail work.
View product →
GacoPoly Permathane Sealant
General-purpose polyurethane sealant for joints, upstands and penetrations.
View product →What we'd specify on your roof
Every roof gets an adhesion test before a scheme is committed. These are the starting points, not the answer.
Asbestos cement
Weathered asbestos cement is one of S42's strongest substrates. Encapsulate in place — no removal, no licensed disposal, and a 20-year warranty in the same visit. Asbestos roof waterproofing →
Profiled & standing-seam metal
Weathered galvanised, Colorbond and profiled steel take silicone directly. Where the roof is pitched and drains freely, 127 acrylic is the cost-effective option.
Felt, asphalt & built-up bitumen
Weathered bitumen coats directly; newer or asphalt-rich felts bleed oil under heat, so the A4271 Bleed Trap base coat goes down first. Required for warranted work over SBS.
Single-ply — EPDM, TPO, PVC
Aged single-ply takes silicone well once cleaned, but TPO and some PVC membranes need a primer. Adhesion test first, every time — this is where schemes go wrong.
Concrete decks
Concrete is the one substrate that always needs sealing. GacoPoly E5691 epoxy primer/sealer, then the silicone system over the top.
Balconies & walkways
Where people walk regularly, silicone isn't the right chemistry. Cold-applied urethane gives the abrasion resistance the traffic demands. Urethane systems →
Cut-edge corrosion
Rust creeping out from side and end laps is the commonest reason a metal roof gets condemned. Detail the affected laps and fixings with the fibre-reinforced grade, then coat over — no sheet replacement, no hot works.
Box & valley gutters
Leaking gutters lined in place over the existing profile, taken up the upstands and sealed into the roof finish. One seamless membrane, no joints left to open up, and the building stays in use.
The distributor is part of the specification
A coating is only as good as the scheme written around it. This is what comes with the product.
Lead time confirmed up front
Delivery across Ireland, with the lead time confirmed when you order, so programmes don't stall waiting on an unknown date.
Free specification & take-off
Written spec, coats, DFT, primer where needed and quantities — at no charge, whether you buy the materials from us or not.
Warranty administration
We hold the QA evidence and issue the manufacturer-backed warranty. One point of contact if it's ever called on.
Approved contractor network
Not installing it yourself? We'll put you in front of contractors already signed off on the system.
Technical support that answers
Adhesion tests, substrate calls, detailing questions, first-day site visits. Email info@duratite.ie and you get someone who knows the product.
Trade accounts
Contractor pricing, account terms and repeat-order support for applicators running Gaco as their standard system.
What the warranty actually covers
Gaco warranties are manufacturer-backed product warranties — issued against the coating, on evidence that it went on to specification.
S42 single coat
- Single-coat silicone at 0.5 mm film build
- Budget option on sound substrates
- Recoatable at end of term
S42 two-coat system
- Two-coat silicone, heavier film build
- White base, grey top — visible coverage check
- Full QA pack: WFT every 20 m², photo and environmental log, batch numbers
- Duratite first-day site visit
Gaco, answered
Who manufactures Gaco?
Gaco is manufactured by Amrize. Duratite supplies GacoFlex in Ireland — we write the specifications and administer the manufacturer-backed warranty.
How long does a Gaco silicone roof last?
Up to 20 years with the full two-coat S42 system applied to specification. At the end of the term the roof can be recoated for another warranty cycle rather than stripped — that's the economic argument for a coating over a replacement.
Does S42 need a primer?
Not on most substrates. S42 bonds directly to weathered metal, polyurethane foam, aged asphalt and aged single-ply. Three exceptions: concrete needs the E5691 epoxy primer/sealer; asphalt and SBS need the A4271 Bleed Trap base coat; TPO and some single-ply membranes may need a primer — we confirm on the adhesion test.
Do I need a separate fleece or fabric?
No — not when you specify SF42, the fibre-reinforced grade, where the reinforcement is built into the product. Plain S42 is not fibre-reinforced. Competitor resin systems rely on a separate fleece because their resins aren't reinforced.
Will it work on an asbestos cement roof?
Yes — weathered asbestos cement is one of S42's best substrates. The roof is encapsulated in place, so there's no removal, no licensed disposal and no disruption to the building underneath. More on asbestos roof waterproofing →
Can it be applied over ponding water?
Standing water has to drain before application. But once cured, S42 is rated for ponding — water sitting on the roof after a storm doesn't degrade it. That's the main thing silicone does that acrylic doesn't, and why it's the default on flat roofs.
What approvals does Gaco hold?
Gaco holds UL 790 Class A, FM Approval PR450562, CRRC 0740-0012 and NSF P151. If a specification demands a specific certification, tell us early and we'll be straight with you about what we can and can't meet.
Can I buy Gaco directly, or do I have to use your contractors?
Either. We supply the trade directly through the shop and on account. If you'd rather it was installed, we'll introduce you to approved contractors — and if your own team is applying it, we'll sign them off on the system so the warranty holds.
What does a Gaco roof cost?
It depends on area, roof condition, detailing and the warranty term you want. We quote the complete system fully installed rather than a materials-only rate, so you're comparing like with like against a replacement. Survey and specification are free.
Tell us about the roof
Send a few photos and a rough size. We'll tell you which Gaco system fits, what it will cost fully installed, and what warranty it carries — free, and without a salesperson turning up uninvited.