Gaco Asbestos Roof Waterproofing in County Mayo — Encapsulation Without Removal

Mayo faces the Atlantic along Ireland’s longest county coastline, about 1,168 km, running from Killary Harbour and Lough Corrib in the south to Killala Bay in the north. Mayo County Council’s development plan describes a county of two halves: Atlantic blanket bog across the west and a limestone lowland landscape to the east. Census 2022 recorded 137,970 people, with Castlebar, Ballina, Westport, Claremorris and Ballinrobe the main towns. Out beyond them are the farmyards, outbuildings and haybarns where corrugated asbestos cement roofs are still a familiar sight.

Weather is the defining local fact for any Mayo roof. Met Éireann’s Belmullet station on the north-west coast averaged 1,241.6 mm of rain a year over 1991 to 2020, and recorded 1 mm or more on about 201 days a year. That means rain falls on more days than not. Asbestos cement that stays wet for that much of the year weathers faster: the cement surface erodes, moss and lichen grow thick, fixings corrode and the sheet ends over the gutters soften. On exposed western ground the ridges and verges take the brunt of the wind. Roofs on the more sheltered eastern lowlands still age, just more slowly.

The practical challenge in Mayo is finding the dry spell. Encapsulation with Gaco urethane coatings, U91 and U92 being the grades used on asbestos cement, seals the existing sheets under one waterproof film, but the roof must be dry and conditions within Gaco’s application limits while the coating goes on and cures. An approved installer will survey first, replace broken sheets, remove moss by a method that does not abrade the cement, and then book the coating into a weather window rather than a fixed date. Because the sheets are not removed, there is no asbestos waste to transport from a remote farm. Duratite supplies the coatings and the approved installer carries out the work.

Looking ahead, the development plan points to Ireland West Airport Knock and its Strategic Development Zone as a prospective enterprise hub in the Atlantic Economic Corridor, but most asbestos cement in Mayo today is on farms. Wherever it is, the Safety, Health and Welfare at Work (Exposure to Asbestos) Regulations 2006 (S.I. No. 386 of 2006, as amended) apply, enforced by the Health and Safety Authority. Mayo County Council is the building control authority, with TGD L 2022 relevant if insulation is changed. The island-of-Ireland reference project is SAICA Warrenpoint, Co. Down.

When you contact us about a Mayo roof, tell us roughly where the building is, how exposed the site is to the west, and what the shed is used for through the year. Photos of the ridges, verges and any moss cover help the installer judge the preparation needed.