Commercial Roof Waterproofing in Dublin — GacoFlex S42 Silicone Roof Coating

As Ireland’s largest commercial property market, Dublin has an enormous area of flat and low-pitched roof: office blocks, retail parks, hotels, logistics units along the M50, and warehousing around Dublin Port, whose operating company has run the port since 1997. Felt, asphalt, single-ply and profiled metal all appear, often on the same estate. When a covering fails, stripping it means skips, weather exposure and disruption to whoever is working underneath — so a liquid-applied coating over a sound existing roof is often the more practical fix. Older office roofs also carry plant, vents and cable routes added over the years, and each penetration is a potential leak.

Met Éireann’s Dublin Airport station recorded an average of 772.5 mm of rain a year over 1991–2020. That is low for Ireland, but it falls on close to 200 days a year with at least 0.2 mm. Frequent light rain on a flat roof with slight deflection or partly blocked outlets leaves shallow standing water, and ponding is what finishes off many conventional coverings. Seams lift, sunlight and frost work on exposed membrane, and water tracks through to ceilings, servers and stock.

GacoFlex S42 is a silicone coating formulated for low-slope roofs where water can pond, and SF42 is its fibre-reinforced grade — the reinforcement is built in, so no separate fleece is laid. Both can be sprayed, brushed or rolled. Applied as a two-coat system, S42 carries a 20-year manufacturer-backed product warranty. Before coating, the approved installer tests adhesion on the existing surface, repairs splits and blisters, clears outlets and checks for wet insulation that would need replacing. Duratite supplies the Gaco materials and passes Dublin projects to an approved installer. Around plant bases and upstands, SF42’s reinforcement earns its place, because those are the points where movement and water concentrate.

On its own, a coating is a weatherproofing repair rather than an energy upgrade. If a Dublin project adds or replaces insulation at the same time, Technical Guidance Document L 2022 comes into play: for a flat roof undergoing material alteration, the average U-value target is 0.25 W/m²K. Dublin City Council’s building control section is the authority within the city. The Health and Safety Authority regulates roof work, so edge protection, fragile rooflights and safe access are all part of the installer’s plan. Hotels, offices and data rooms beneath flat roofs usually stay in use throughout.

Many Dublin roof leaks are reported long before anyone looks at the roof itself. A stain appears on a hotel bedroom ceiling, a drip lands in a server room or water collects beside a rack in a logistics unit near the airport, and the facilities team starts a log. That log is one of the most useful things to hand the installer. Note the date of each leak, the weather at the time, and exactly where it appeared inside. Water often travels under a covering before coming through, so a pattern of leaks after wind-driven rain points to different causes than drips after every light shower. Beyond the log, collect roof plans or drawings, any warranty or maintenance records for the existing covering, and details of plant, vents, solar panels or cable routes added since it was laid. Access needs thought in a busy city. Confirm where a scaffold tower, hoist or roof ladder can be set up, whether the roof has permanent edge protection or a safety line, and whether roof access passes through occupied areas such as guest corridors or tenants' offices. Buildings on shared estates may need the landlord or management company to approve contractors and working hours. With that information, the approved installer can test adhesion on the existing surface, check for wet insulation and plan a programme that keeps the building weathertight each evening. Duratite supplies the Gaco silicone and arranges the introduction to an installer covering Dublin.