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Commercial Roof Waterproofing Ireland — GacoFlex Coating Systems by Duratite

Seamless, cold-applied GacoFlex silicone, acrylic and urethane systems for commercial and industrial roofs across Ireland and Northern Ireland — waterproofing, cut edge corrosion, asbestos encapsulation, gutter lining and cool-roof coatings, all over your existing roof with no tear-off.

No tear-off — coat the roof you have20-year manufacturer-backed warrantyCold-applied — no hot works

Building owners, tenants and facilities managers: get free expert advice and a fixed-price quote. We survey and specify, then match you with an approved contractor from our Ireland-wide network — backed by a 20-year manufacturer-backed product warranty.

Commercial metal roof coated with a seamless GacoFlex silicone waterproofing membrane
GacoFlex — cold-appliedSilicone · acrylic · urethane, over your existing roof
20yr
Manufacturer-backed product warranty
60–80%
Typical saving vs full replacement
3
Systems — silicone, acrylic, urethane
IE + NI
Nationwide survey & install
The modern standard

How liquid roof waterproofing works

Liquid roof waterproofing is a cold-applied coating rolled, brushed or sprayed straight onto your existing roof. It cures into a seamless, fully-bonded elastomeric membrane with no joints, laps or mechanical fixings — sealing exactly the points where commercial roofs leak. GacoFlex systems bond to metal, felt, single-ply, concrete and asbestos-cement substrates, so there is no tear-off, no re-sheeting and no need to close the building.

  • Seamless membrane — no laps, joints or fixings to fail
  • Roof restoration, not replacement — keep the existing roof in place
  • Fully operational — cold-applied over the live building
Free commercial roof surveySubstrate, ponding, cut edges, access and drainage — then a fixed priceBook a Survey
GacoFlex silicone seamless fully bonded membrane on a commercial roof

GacoFlex silicone · seamless, fully bonded

Bonds to metal, felt, single-ply, concrete and asbestos-cement
Silicone is a liquid coating — not a foam, and not part of any foam range
SF42 is fibre-reinforced, so laps and details need no separate scrim
Recoatable at end of life — silicone on silicone, no tear-off
GacoFlex is an Amrize brand · 20-year manufacturer-backed product warranty
Why building owners choose GacoFlex

GacoFlex coating system — key benefits

Stop leaks permanently

A seamless membrane bridges the joints, laps and fixings where commercial roofs leak — water ingress stops for good.

No Tear-Off Required

Restore the roof you have instead of stripping and re-sheeting it — a fraction of the capital cost and disruption.

No business disruption

Cold-applied over the live building. No tear-off, no vacating, no downtime for your operation or tenants.

Up to 20-year warranty

A 20-year manufacturer-backed product warranty from GacoFlex (an Amrize brand), installed by an approved contractor from our network across Ireland and Northern Ireland.

Improve your BER rating

White reflective coatings cut roof surface temperature and help commercial landlords improve their BER.

Cold-applied — no hot works

No flame, no torch-on, no fire risk. Ideal for occupied, high-risk and safety-sensitive commercial sites.

Our products & systems

Three GacoFlex coating systems

Whether you need a highly reflective energy-saving coating or a robust waterproof membrane for long-term protection, we specify the GacoFlex system that best matches your building’s roof, drainage and budget.

GacoFlex S42 silicone roof coating pail
Silicone · flagship

GacoFlex Silicone Coating System

A premium 100% silicone membrane for roofs needing the highest levels of waterproofing, flexibility and long-term protection — built around Gaco S42, with SF42 fibre-reinforced seam seal at laps and details.

  • Seamless, fully-adhered membrane — no joints or weak points
  • Permanently resists ponding water, UV and thermal movement
  • Single-coat over metal, flat and problem leaking roofs
  • Extends roof life and cuts long-term maintenance
GacoFlex 127 Series acrylic waterproof roof coating pail
Acrylic · cool roof

GacoFlex Acrylic Coating System

A cost-effective, weather-resistant elastomeric acrylic (127 Series) ideal for large commercial roofs where reflectivity, surface protection and value are the priorities.

  • Reflective white finish lowers roof temperature and cooling costs
  • Strong adhesion to metal, cement-fibre and coated surfaces
  • Excellent weather, rain and UV durability
  • Fast application and drying over large roof areas
GacoFlex U9101 urethane base coat pail
Urethane · heavy-duty

GacoFlex U9 Series Urethane System

A heavy-duty two-coat urethane system (U91 base + U92 aliphatic top coat) for roofs that demand exceptional impact, abrasion and chemical resistance — pedestrian decks, plant rooms and podiums.

  • U91 high-build elastomeric base for flexibility and adhesion
  • U92 UV-stable, walk-on top coat that won’t yellow or chalk
  • Outstanding tensile strength — bridges movement and cracks
  • Cold-applied, fully bonded — no hot works, no tear-off
Not sure which system? Book a survey and we will specify it for your roof.
The complete GacoFlex silicone system

Gaco S42 and its companion products

Gaco S42 is the flagship — but a fully warrantied installation also relies on two specialist companion products. Together they form the silicone roof system specified across warehouses, factories and commercial buildings.

Gaco Wash concentrated roof cleaner pail

Step 1 · preparation — Gaco Wash

Specialist cleaning solution that removes dirt, algae, moss and surface contaminants — ensuring maximum adhesion of the silicone coating system.

Gaco SF42 SeamSeal fibre-reinforced silicone sealant pail

Step 2 · detailing — Gaco SF42 SeamSeal

Fibre-reinforced silicone seam sealant for laps, fixings, fasteners and detail areas. High-build formula bridges joints and movement points permanently — no separate scrim needed.

GacoPatch instant-cure silicone roof repair sealant

Emergency repair — GacoPatch Silicone Waterproofing

Instant-cure silicone sealant for targeted leak repairs and emergency waterproofing — can be applied in wet or dry conditions, even during active rainfall.

Silicone · acrylic · urethane

Which system is right for your building?

Duratite specifies all three GacoFlex systems — each has a place. The right coating depends on your roof’s condition, drainage, traffic level and long-term goals. We confirm the best fit on a free site survey.

Compare the systemRECOMMENDEDSilicone — Gaco S42Flagship · flat & low-slopeAcrylic — GacoFlex 127Cost-efficient · cool roofUrethane — U91/U92Heavy-duty · trafficked
Best suited toFlat & metal roofs with ponding waterLarge reflective metal roofs & cool-roof projectsPedestrian decks, plant rooms & trafficked areas
Ponding water resistanceExcellentPoorVery good
UV / weather resistanceOutstandingVery goodOutstanding U92 aliphatic top coat
Foot-traffic durabilityLimitedLimitedWalk-on rated
Cool-roof / energy savingsHigh (white)High (white)Standard
Recoatable at end of lifeYes silicone-on-siliconeYes compatible substrateYes recoat with U92
ApplicationSingle coat, cold-applied2-coat, cold-applied, fast drying2-coat (base + top), cold-applied
Manufacturer warrantyUp to 20 yrsUp to 15 yrsUp to 20 yrs
Relative costLowerLowerHigher
Get a system recommendation — free, from a survey, with no obligation.
Independent comparison

GacoFlex vs Polyroof vs Triflex

Specifiers, contractors and building owners regularly compare these systems for commercial flat-roof and metal-roof projects. The table below sets them out side-by-side using publicly available manufacturer data — no spin. Use it as a starting point, then talk to a specialist for a recommendation that suits your roof.

Compare the systemsRECOMMENDEDGacoFlex S42Duratite — supply in IrelandPolyroofUK manufacturerTriflex ProDetailPMMA · Germany
System type100% silicone, single-coatPolyester-reinforced PUPMMA (acrylic resin)
Manufacturer warrantyUp to 20 yearsUp to 20 years Protec / IBG variantsUp to 25 years specifier scheme
ApplicationCold-applied, brush/roller/sprayCold-applied, fully reinforcedCold-applied, fast-cure PMMA
Cure time (typical)4–8 hrs rainproof; 24 hrs full24–48 hrs resin + reinforcement~30 mins rainproof PMMA
Solar reflectance (CRRC)SR 0.91 white S42Not CRRC ratedNot published
Ponding water ratingPermanent ponding ratedDrainage required
Typical installed cost in IrelandFixed price after free surveyAsk the manufacturerAsk the manufacturer
Pedestrian ratedAdd U92 top coat for trafficYes with anti-slip topcoatYes heavy-duty PMMA
Best forFlat & metal roofs with ponding; refurbishment over existingFlat roof refurbishment with reinforcement layerComplex details, balconies, fast-cure deadlines
Our own figures are Duratite’s. We do not publish installed prices for other manufacturers’ systems — those vary by contractor and specification, and only they can quote them. Everything else here is compiled from publicly available manufacturer data. Talk to a Duratite specialist for an independent recommendation — the right system for your roof, not an allegiance. Ask for an independent recommendation.
Costs

How much does commercial roof waterproofing cost in Ireland?

Commercial roof waterproofing with GacoFlex silicone and heavy-duty urethane systems are priced per roof as a fixed written price. All quotes are fixed-price after a free site survey from Duratite’s technical team.

Roof sizeRECOMMENDEDGacoFlex coating costFully installedFull replacementSaving
500 m²Fixed price after surveyStrip-out, disposal & new roof60–80%
1,000 m²Fixed price after surveyStrip-out, disposal & new roof60–80%
2,500 m²Fixed price after surveyStrip-out, disposal & new roof65–80%
5,000 m²+Fixed price after surveyStrip-out, disposal & new roof70–80%
Typical savings of GacoFlex coating vs full replacement. Your fixed price is confirmed after a free survey. What drives the cost up or down? Substrate condition — pressure washing, primer, rust treatment and lap-seam repairs; older felt or corroded metal needs more prep than sound concrete or single-ply. Roof access — cherry-picker, MEWP, abseil or fixed scaffold carry different cost profiles. System specification — single-coat S42 is higher per litre but covers more m² per pail; 2-coat acrylic and urethane need two passes. Reinforcement at laps and details — fibre-reinforced GacoPatch or SF42 over fixings, end laps, gutters and penetrations adds cost, but is non-negotiable on profiled metal. Project size — 3,000 m²+ attracts better unit pricing; under 500 m² carries a higher per-m² rate.
Compatible substrates

Roof types & substrates we treat

Our coatings are engineered for a wide variety of existing commercial roof constructions. Gaco coatings adhere directly to most surfaces — including weathered or porous substrates — with minimal surface preparation required in many cases.

  • Corrugated metal (galvanised, coated, painted)
  • Aluminium, steel & zinc profile sheeting
  • Cement-fibre corrugated roofs
  • Asbestos sheet roofs
  • Felt, single-ply & built-up flat roofs
  • Concrete decks & foam-insulated pitched decks
Direct-to-substrate · minimal prepNo tear-off, no re-sheeting, no skips of stripped roofCheck My Roof
Industrial warehouse roof prepared for a GacoFlex liquid waterproofing system

Direct-to-substrate · minimal prep

No tear-off of the existing roof is needed on any of these substrates
By sector

Tailored specifications for every industry

We specify the system, reinforcement and programme to each.

Warehouse & distribution

Large-area profiled metal, cut edge, lap-seam leaks and ponding around rooflights. S42 single-coat, fixed price after survey. 2,000–20,000 m²+.

Schools & academies

Patchwork felt and single-ply on tight budgets. 127 acrylic or S42 in half-term windows; white topcoat for BER uplift. Half-term programmes, BER uplift.

Hospitals & HSE

Zero clinical disruption; low-odour, cold-applied. Plant decks above theatres via U91/U92 walk-on urethane, no shutdown.

Offices & corporate HQs

A better BER. S42 with CRRC SR 0.91 reduces summer heat gain and lifts the BER.

Retail & shopping centres

Leak-sensitive (stock liability), trading-hours-sensitive. Out-of-hours rapid-cure silicone, rainproof in 4–8 hrs.

Industrial & factory units

Cut-edge corrosion, ponding, fume exposure and vibration. S42 + SF42 fibre-reinforced, cold-applied, no hot work.

Cool roof & BER

How a cool-roof coating helps the BER

GacoFlex “cool roof” coatings use a highly reflective white finish to cut metal-roof surface temperatures, reduce cooling costs and improve BER ratings — backed by warranties of up to 20 years.

A BER is required when a commercial property is sold or let.

Ask about a cool-roof specWe set out what a reflective coating can deliver for your BERAsk About a Cool-Roof Spec
85%Typical reduction in solar heat absorption vs dark felt / oxidised metal
SR 0.91 — CRRC initial solar reflectance, white S4225–35°C summer surface-temp reduction on a 2,000 m² warehouseA better BER
White reflective cool-roof coating on a large commercial metal roof
Case studies — real projects, real numbers

Duratite projects in the UK and Northern Ireland

Each case shows the building type, the problem, the system applied and the outcome.

Units 1–5 Tresidder Close, Falmouth — profiled metal roof after GacoFlex S42 Series silicone coating

Units 1–5 Tresidder Close, Falmouth, England — 687 m² roof

Original profiled metal roof coated in place with the GacoFlex S42 Series silicone system — no tear-off and no stripping of the existing sheets. Coating completed July 2025. Building owner Treveth Holdings LLP; installed by Gwella Contracting Solutions Ltd.

Industrial units687 m²GacoFlex S42 SeriesNo tear-off
How it works

From your enquiry to a warrantied roof

We’re your single point of contact: Duratite surveys and specifies the system, then matches you with a vetted contractor from our Ireland-wide approved network to carry out the work.

1

You enquire

Owners, tenants and facilities managers send the building, roof and a few photos.

2

Free site survey

Substrate, ponding, cut edges, access and drainage assessed on site.

3

Design & fixed quote

System, reinforcement and any traffic top coat, at a fixed, fully installed price.

4

Approved contractor installs

A vetted contractor from our approved network cold-applies the system — no tear-off, building stays open.

5

Warranty & handover

20-year manufacturer-backed product warranty and documentation.

Large commercial roof finished with a seamless GacoFlex silicone waterproofing system
Got an urgent roof leak?

Protect your commercial roof — without full replacement

Send the building type, roof and a few photos and we’ll book your free site survey. For active leaks, GacoPatch gives an instant-cure repair — even in the wet — while we plan the full system.

FAQ

Commercial roof waterproofing questions

Straight answers on cost, lifespan, systems, asbestos, cut edge, cold-weather application, BER and warranties. Can’t see yours? Ask us directly and we’ll come back to you the same working day.

How much does commercial roof waterproofing cost in Ireland?
Commercial roof waterproofing with liquid-applied coating systems is priced per roof after a free survey, because cost depends on roof size, condition, access requirements and the system specified. Coating an existing roof typically costs a fraction of full replacement. Duratite provides free roof surveys and no-obligation, fixed-price quotations for all commercial roof types.
How long does commercial roof waterproofing last?
GacoFlex silicone and acrylic roof coating systems are backed by manufacturer-backed product warranties of up to 20 years. With proper maintenance, coated roofs can last significantly longer. At end of life, the coating can be recoated without tear-off, providing continued protection decade after decade.
Can you waterproof a commercial roof without replacing it?
Yes. Liquid-applied roof coatings such as GacoFlex are applied directly over your existing roof substrate — whether metal, felt, single-ply, or asbestos cement — creating a seamless, fully bonded waterproof membrane. There is no need for costly tear-off or re-sheeting, and your building remains fully operational during the work.
What is the best — and most durable — waterproofing system for a commercial flat roof?
For commercial flat roofs, GacoFlex 100% silicone roof coating is the leading choice because it is permanently resistant to ponding water — it will not soften, crack or delaminate even under standing water, does not break down under UV exposure and does not become brittle with age, holding its flexibility and waterproofing performance for 20+ years. At end of life it can be recoated without removal, providing indefinite roof protection. For large-area roofs with good drainage, GacoFlex acrylic coatings offer a fast-drying, cost-effective alternative. Both systems form a seamless membrane that eliminates joints, laps and fixings — the most common points of failure on flat roofs.
Do you need planning permission for commercial roof waterproofing?
In most cases, no. Applying a liquid waterproof coating over an existing commercial roof is classified as maintenance and repair, not a material alteration, so planning permission is not required. However, listed buildings or properties in conservation areas may have additional requirements. Duratite can advise on any regulatory considerations during your free roof survey.
What types of commercial roof can be waterproofed with coating systems?
GacoFlex coating systems can waterproof virtually any commercial roof type, including profiled metal roofs (steel and aluminium), flat roofs (felt, single-ply, built-up), asbestos cement roofs, concrete roofs, and gutters. Common building types include warehouses, factories, industrial units, offices, retail units, schools, hospitals, and agricultural buildings.
What is cut edge corrosion and how do you fix it?
Cut edge corrosion occurs when the exposed edges of profiled metal roof sheets lose their factory coating, allowing moisture to corrode the metal at lap joints and sheet ends. Left untreated, it causes persistent leaks and structural damage. Treatment involves cleaning and preparing the affected areas, applying a corrosion-inhibiting primer, then sealing with a flexible waterproof coating. Duratite specifies GacoFlex systems for cut edge corrosion repair, backed by manufacturer-backed product warranties.
Is silicone or acrylic roof coating better for commercial roofs?
It depends on your roof’s conditions. GacoFlex silicone is best for roofs with ponding water, permanent puddles, or areas prone to standing water — silicone will not degrade in constant water contact. GacoFlex acrylic is ideal for large-area roofs with good drainage where fast application and cost-effectiveness are priorities. Both offer excellent UV resistance, reflectivity, and long-term waterproofing. A free Duratite roof survey will determine which system is right for your building.
Can you apply roof coating in winter or cold weather?
GacoFlex silicone roof coatings can be applied in temperatures as low as 0°C, making them suitable for year-round application across Ireland and Northern Ireland. Acrylic coatings require temperatures above 5°C and no rain forecast for 24 hours. Your Duratite-approved contractor will schedule installation around weather conditions to ensure optimal adhesion and curing.
Does roof coating stop leaks on a commercial building?
Yes. GacoFlex liquid roof coatings create a seamless, fully bonded waterproof membrane across your entire roof surface, eliminating the joints, laps and fixings where most leaks originate. For active leaks, GacoPatch silicone sealant provides an instant-cure emergency repair that can be applied even in wet conditions. Once the full coating system is applied, it permanently prevents water ingress.
What is liquid applied roof waterproofing?
Liquid applied roof waterproofing is a cold-applied coating system that is rolled, brushed or sprayed directly onto an existing roof surface. It cures to form a seamless, elastomeric waterproof membrane with no joints or mechanical fixings. GacoFlex systems are a leading liquid-applied waterproofing solution, offering silicone, acrylic and urethane formulations for different roof types and conditions.
Is EPDM or liquid waterproofing better for commercial roofs?
Liquid-applied coatings like GacoFlex offer significant advantages over EPDM for commercial roof refurbishment. Liquid systems are applied directly over existing substrates without tear-off, form a seamless membrane with no joints to fail, and conform to complex roof details. EPDM requires mechanical fixing or adhesive bonding, creates seams that can fail over time, and typically requires removal of the existing roof covering. For new-build flat roofs, EPDM can be appropriate, but for refurbishment of existing commercial roofs, liquid waterproofing is faster, less disruptive and more cost-effective.
What preparation is needed before commercial roof waterproofing?
Surface preparation for commercial roof waterproofing includes pressure washing or mechanical cleaning to remove dirt, moss and loose material; treatment of any rust or corrosion on metal substrates; repair of damaged areas, holes or failed fixings; and application of a compatible primer where required. GacoFlex systems bond to most existing roof substrates including metal, felt, single-ply membranes, asbestos cement and concrete. No tear-off of the existing roof is needed.
Can you waterproof an asbestos roof without removing it?
Yes. GacoFlex roof coatings can be applied directly over asbestos cement roof sheets, encapsulating the asbestos fibres and providing a new waterproof membrane without the enormous cost and regulatory burden of asbestos removal. HSA guidance recognises managing sound asbestos cement in situ rather than removing it, and encapsulation is one of the recognised ways to do that. The coating seals the surface, prevents fibre release, and extends the roof’s serviceable life by 20+ years. All asbestos-roof work is survey-led and carried out by trained operatives with the correct controls.
How long does it take to waterproof a commercial roof?
Most commercial roof waterproofing projects are completed within 1–3 weeks depending on roof size and complexity. A typical 1,000m² warehouse roof takes approximately 5–7 working days. GacoFlex silicone coatings cure rapidly and are rain-resistant within hours of application. Your building remains fully operational throughout — there is no need to close or vacate the premises during installation.
Do commercial roof coatings reduce energy costs?
Yes. GacoFlex white reflective roof coatings reflect a high proportion of solar radiation — white S42 carries a CRRC initial solar reflectance of 0.91 — significantly reducing heat absorption through the roof. This can lower internal temperatures in summer, reducing air conditioning and cooling costs. Cool roof coatings also contribute to a better BER (Building Energy Rating).
What warranty do you get with commercial roof waterproofing?
GacoFlex commercial roof waterproofing systems are backed by manufacturer-backed product warranties of up to 20 years covering material defects and waterproofing performance. Warranties are issued by GacoFlex (an Amrize brand), one of the world’s largest coating manufacturers. At end of warranty, the roof can be recoated to extend protection without replacement. Duratite also ensures all installations are carried out by trained, approved contractors.
Can roof waterproofing be applied over an existing metal roof?
Yes. GacoFlex liquid roof coatings are specifically designed for application over existing metal roof substrates including profiled steel, aluminium, galvanised and pre-coated metal sheets. The coating bridges fixings, laps and joints — the most common leak points on metal roofs — creating a seamless waterproof barrier. Cut edge corrosion is also treated as part of the process. No removal of the existing metal sheets is required.
Free roof survey

Get a fixed-price roof waterproofing quote

Tell us about your roof — type, approximate size and the problem. We survey it free, design the right GacoFlex system and issue a fixed quote with a 20-year manufacturer-backed warranty.

Reviewed by a roof coatings specialistNo obligation, no hard sellSilicone, acrylic or urethane systemsIreland-wide approved contractor network

Send my enquiry

Prefer to talk? Email info@duratite.ie — Mon–Fri, 8am–5pm.

Mon–Fri 8am–5pm · info@duratite.ie

Areas we cover

Duratite across Ireland and Northern Ireland

Free survey and fixed written specification in every county, installed through our approved installer network. Choose your area.

Commercial Roof Waterproofing

Roof Waterproofing DublinRoof Waterproofing CorkRoof Waterproofing GalwayRoof Waterproofing LimerickRoof Waterproofing WaterfordRoof Waterproofing KilkennyRoof Waterproofing DroghedaRoof Waterproofing DundalkRoof Waterproofing AthloneRoof Waterproofing SligoRoof Waterproofing LetterkennyRoof Waterproofing TraleeRoof Waterproofing EnnisRoof Waterproofing NavanRoof Waterproofing WexfordRoof Waterproofing BelfastRoof Waterproofing DerryRoof Waterproofing NewryRoof Waterproofing LisburnRoof Waterproofing Armagh
Roof Waterproofing by county (32)
County CarlowCounty DublinCounty KildareCounty KilkennyCounty LaoisCounty LongfordCounty LouthCounty MeathCounty OffalyCounty WestmeathCounty WexfordCounty WicklowCounty ClareCounty CorkCounty KerryCounty LimerickCounty TipperaryCounty WaterfordCounty GalwayCounty LeitrimCounty MayoCounty RoscommonCounty SligoCounty CavanCounty DonegalCounty MonaghanCounty AntrimCounty ArmaghCounty DownCounty FermanaghCounty LondonderryCounty Tyrone

Technical guides for Ireland

TGD L 2022 insulationImprove your BERAsbestos cement roofsFarm building condensationWarehouse insulationFlat roof leaksOpen vs closed cellNorthern Ireland guide

All areas we cover →

Free Site Survey

Get a Free Site Survey & Quote

Tell us about your building and we’ll recommend the right system — foam, waterproofing or both — surveyed, specified and quoted at no cost.

  • Reviewed by a Duratite specialist
  • No obligation, no hard sell
  • One team from survey to warranty
  • Ireland and Northern Ireland coverage
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