Back in 2014, Trinity College Dublin decided to address the student accommodation crisis in the capital by announcing plans to demolish Oisín House and to build a 250-unit student accommodation block in its place, located on Pearse Street and at the time occupied under lease by the Department of Social Protection. The building contract was awarded to Bennett Construction and the project, designed by McCullough Mulvin Architects and O’Mahony Pike Architects, consisted of three new, interconnected buildings with each building featuring a stone-sculptured, multi-pitched and multi-faceted roof – an eye-catching design that came with its unique challenges.
Roofing installed by Titan Roofing
For the project Soprema provided a waterproofing solution for the roofs and worked closely with Titan Roofing. Titan Roofing carried out the work of waterproofing Oisín House’s more than 70 different roof planes, using Soprema systems. Keith Proudfoot, the Managing Director at Titan Roofing explained “We had worked with Soprema a number of times before, for instance on New Priory. When tendering for Oisín House, we proposed a Soprema system because we knew they had the technical capabilities to make the project a success.”
Soprema’s heavy involvement in the initial design process
Prior to commencing the roofing works, Soprema worked on the design of the Oisín House roofs together with O’Mahony Pike Architects, Bennett Construction, and Titan Roofing. The roof pitches of the three-block student accommodation have varying angles and arise from three different floor levels, leading to 74 different roof planes and an enormous amount of detailing. Keith Proudfoot explained “Before the project got to site, we had weekly meetings for eight months, figuring out the design and how everything was going to work together.”
As the entire roof of Oisín House is covered in a stone cladding, Soprema had to make sure the detailing was incredibly robust. The team of Titan Roofing, in turn, had to manage working underneath the steel structure that was already in place to hold the stone. Keith Proudfoot explained “This greatly increased the level of difficulty. In addition, we had to give the waterproofing extra care and attention, making sure it was fully sealed, watertight and flood tested before it was handed over, because once the roof would be fully covered in stone, it would become impossible to reach the waterproofing.”
Bitumen felt warm roof solution by Soprema
In April 2019, the works on the roof started, and they took fifteen months to complete. Due to the steepness of some of the roof slopes (the angles of the roof planes range from 25 up to 72 degrees), special scaffolds had to be erected to guarantee safe access for workers, as well as other design solutions for the transfer of the loads to the roofs. Keith Proudfoot explained that working on the almost vertical slopes made it tricky to even stand on the roof. “We took a number of safety precautions, such as harnesses hooked over the installers’ heads, which really restricted their movements. Sometimes we had to walk on a ladder with a harness on and install the torch-on system like that.”
Despite their complexity, all of the works were completed with existing Soprema systems and are now covered by Soprema’s 25-year warranty. Titan Roofing installed 180 millimetres of SOPRATHERM T insulation and a warm roof build-up in bitumen felt, using a SOPRAROCK underlay and a SOPRALENE FLAM 250 AF cap sheet. For the detailing and accessories, liquid ALSAN was chosen. Keith Proudfoot explained “The details were very intricate, and the area was small and restricted, so ALSAN was a perfect choice for that situation.” To guarantee the necessary robustness, roof details would often be reinforced with other details: a bitumen felt detail for instance being reinforced with liquid ALSAN.
Complicated building, impressive end result
Once the works were underway, Soprema did regular site inspections and site reports. Keith is very happy with the collaboration, calling it “seamless” - “Soprema’s service was great. Any changes during construction were very easily managed and presented to the architect for approval. Everything was done in a timely manner.”
Fergus Byrne, Technical Team Manager at Soprema Ireland, notes that “Oisín House is probably the most complicated building we have ever worked on”. Keith, too, says that “in almost twenty-five years in roofing, this was absolutely the most complex project that we encountered. It was a great learning experience for Titan Roofing and for Soprema; we worked very well together to overcome all of the detailing and the difficulties presented by this project. The finished building looks fantastic.”
The end result looks stunning indeed. Providing 250 student rooms and featuring an undulating stone roof folded into the most complex angles, Oisín House truly is a project to be proud of.
Get in touch
Contact our experts on technical@soprema.ie to find out how our solutions can be incorporated in your project.