Introduction
The Georgian building in Mountjoy Square is a five storey mid terrace property, formerly used by a technical college. The impressive building, suitable for a wide variety of commercial tenants required refurbishment. With evidence of water ingress into the building below, the roof required renovation to provide a robust, watertight building for future tenants for the long term.
The challenge
The existing roof waterproofing was an asphalt roof system. A solar reflective coating had been applied at some time in the roof’s history. In addition, there was evidence of torch on felt patch repairs as well as blisters in the asphalt surface. Complete removal of the existing solar reflective coating was undesirable for both project time and budget requirements. Consequently, an effective overlay option was sought. Any such overlay solution needed to ensure that the bond of the new waterproofing membrane was secure to the asphalt substrate below, rather than solely to the reflective coating. Bonding to the solar reflective coating would mean that the waterproofing membrane would not withstand potential wind uplift stresses. In addition, failing mortar joints were found at intersection between the flat roof and pitched roof.
The solution
The Triflex Technical team carried out an assessment of the flat roof area to propose the best technology for an overlay solution. Assessment included testing in situ to establish the correct pre-treatment and priming of the existing surface to achieve a fully bonded cold applied liquid waterproofing system to the reflective coated asphalt substrate.
The resulting bespoke project specification proposal recommended the Triflex ProTect waterproofing system together with the Triflex ProDetail system for the upstands and details. Both the Triflex ProTect liquid waterproofing membrane and Triflex ProDetail systems are highly compatible with asphalt substrates, with the technologically advanced PMMA resins forming exceptionally strong bonds rapidly.
Alongside a general clean, the solar reflective coated asphalt required only a light grind in places, rather than removal. Repairs were required to some areas of the existing substrate prior to overlay with the Triflex ProTect liquid membrane. This included the removal of layers of previously installed torch on felt patch repairs as they were found to be saturated. The asphalt blisters were cut out and filled with Triflex PMMA based repair materials, which were also used to repair the failing mortar joints. The swiftly cured repair materials meant that the substrate was soon ready for overlay by the Triflex ProTect system.
Triflex ProDetail is a fleece reinforced system that is ideal for waterproofing upstands, gutters and roof penetrations due to its thixotropic formula, allowing it to be installed onto vertical surfaces. Here it was used to provide seamless waterproofing to awkward forms of the mushroom vents and balustrades, as well as upstands and ridge capping.
With the project works taking place in November, the certified Triflex ProTect and Triflex ProDetail systems provided a robust seamless waterproofing that rapidly cured even in the low winter temperatures. The Triflex systems are rainproof in just 30minutes, providing further reassurance for the program of works in the Dublin winter.
The Mountjoy Square roof project was soon completed without the need to fully remove the existing solar reflective coating. The asphalt overlay solution providing a cost-effective approach and far less waste than any strip up and replacement option. The asphalt overlay approach was not compromised by the presence of a solar reflectance coating thanks to the proven high compatibility of Triflex waterproofing systems. All works were carried out to a high standard by Triflex Authorised Contractor, Larsen Contracts.
