York NHS trust HQ roof refurbished with no disruption to staff


Leaking roof is put right using Sika Liquid Plastics innovations

Early this year it was discovered that the original rock asphalt roof and balcony of the York Teaching Hospital NHS Foundation Trust headquarters was in a very poor condition and in desperate need of repair.

Located just next door to Scarborough Hospital, the office building would have to be in constant use during the refurbishment, due to the vital nature of the services its staff provide. This presented a challenge for Sunderland-based roofing contractor, Group Tegula, working alongside the Sika Liquid Plastics refurbishment team.

An initial survey by Sika Liquid Plastics assessed the condition of the failing roof, which was allowing water ingress and damaging the building below. The project was then taken forward to the specification stage, where it was decided that the sensitive nature of the hospital site, combined with working on a roof and balcony of an occupied building, required the use of a waterproofing product that would cause as little disturbance as possible.

It was essential that the product chosen would enable fast installation without the risks associated with hot works. Not only were speed and safety key – a low-odour solution was required so as not to disrupt those working in the offices.

In order to meet these vital requirements, Decothane Ultra, a low-odour liquid-applied roofing membrane from Sika Liquid Plastics, was specified for the refurbishment. Decothane Ultra uses patented technology, which has been developed specifically for use in highly-sensitive areas, such as hospitals, food manufacturing plants and schools. Odournet, a team of independent consultants that develops, manages and delivers top level expertise on sensory analysis techniques, found Decothane Ultra to be much lower odour when benchmarked against other single-pack polyurethanes available in the market. Plus, as the product is cold applied, it requires no heat or naked flame during application, a must for populated areas where health and safety is paramount.

Sarah Spink, product manager at Sika Liquid Plastics said: “One of the main issues facing the use of liquids in various refurbishment situations, still relates to the odour emitted during and for a short period after application. Decothane Ultra negates this problem, with its innovative formulation that achieves scientifically-proven lower odour, as well as offering a cold-applied option which again suits more-sensitive areas.”

The roof of the headquarters included parapet detailing, plant and a plant room. Group Tegula, a Sika Liquid Plastics Quality Assured Contractor, was able to quickly install the liquid membrane over the top of the existing roof covering, even around the more-difficult areas. This was thanks to the liquid application and unique formulation of Decothane Ultra, which allowed the use of Glass Fibre Matting around plant details.

Dave Murray at Group Tegula said: “We are always pleased with the way the liquid membrane goes down – it’s fast and easy to use, as well as being rapidly rain resistant, meaning the roofing is free from rain damage immediately after application. Any odour from the product quickly disappeared and didn’t cause any issues with the staff using the building.”

Group Tegula also installed a Sika Liquid Plastics Versirail on the roof from Latchways, the edge protection system specialists, to ensure any subsequent inspection or maintenance on the roof could be conducted safely by staff or contractors.

Murray said: “Access was very difficult during the project. We were three storeys up at the front of the building. We had to set up a debris chute to dispose of waste as there was no way of getting it back out through the offices.”

To make sure that the project caused as little disruption to staff as possible, the team liaised closely with buildings manager, John Nicolls. Work was scheduled for weekends and evenings when possible, and had to be undertaken with speed, precision and minimum noise.

Alongside the roof refurbishment, the communal balcony area, accessible via French doors from the office, needed to be waterproofed. As it would be used daily by staff for breaks and meetings, it was important that it looked aesthetically pleasing. As Decothane Ultra is liquid applied, it allowed for a seamless and attractive finish, which was well received by the client and staff alike. Group Tegula also installed a bespoke handrail around the edge of the balcony to finish the job.

Steve Cookson, technical services manager at Sika Liquid Plastics, said: “Our single-point guarantee covers the entire roofing system from the deck upwards and gives the client peace of mind for years to come. Decothane Ultra is also BBA certified, a quality assurance that is only awarded to the very-highest standard of building products.

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“We continue to drive forwards with customer focused product advancements – first there was the single pack, then the 15, 20 and 25 year systems, root resistant technology, balcony systems and continual aesthetic developments. Now, Decothane Ultra presents opportunities for architects, specifiers and contractors, to use liquid waterproofing within sensitive areas. Feedback so far from those who use our products is that this is a real breakthrough.”