Sika Sarnafil products were used to provide a long-lasting, waterproofing solution for the Napp Building, home of Napp Pharmaceuticals, Cambridge.
Iconic in design, the Napp building is famously nicknamed ‘the Toast Rack’. Housing a multi-million pound pharmaceutical manufacturing facility, it was essential that the building remained watertight and fully operational throughout its roof refurbishment.
Napp’s unique design and architectural significance meant that the aesthetics of the roof were also of great importance, requiring a high quality product and the highest levels of detail, accuracy and craftsmanship.
The project called for an overlay of a 25-year old Sarnafil system and an upgrade of the insulation to current standards. Although the membrane was still performing well, the client wished to refurbish the roof as a precautionary measure, ensuring the continued weatherproofing of the building.
In partnership with Sarnafil Plus, a specification was created to match the existing clean look of the building, and provide a long-lasting, waterproofing solution.
To begin, the original membrane was cut at the perimeter of the roof and at all penetrations. SarnaTherm insulation was then laid in a staggered bond pattern, and fastened with Sarnafil SBT thermally broken stainless steel fasteners.
This was followed by loosely laid Sarnafil S327-18EL Light Grey roofing membrane, in the same direction as the roof deck corrugations. All side and end laps were hot air welded, and then the membrane was mechanically fastened to the metal deck with Sarnabars.
This flame-free application method allowed the building to remain open throughout the work.
To ensure the building remained watertight, careful planning, temporary waterproofing, and night joints were required. Movement of materials and deliveries were also carefully planned and monitored, to ensure minimal disruption to those using the building.
The project was undertaken by Roofing Contractors Cambridge (RCC), in two phases between 2015 and 2016.
As a Sika Sarnafil contractor, RCC has been fully trained in the high quality installation of Sarnafil products, as well as health and safety. Detail work was carried out in accordance with Sarnafil’s exacting standard detailing principles, published Sarnafil technical advice, and the recommendations of the project’s Sarnafil Plus Refurbishment Surveyor during frequent site visits.
Sarnafil completed a final inspection of the project, deeming the workmanship to be of an extremely high standard, and awarding the system a Sarnafil Plus 20-year guarantee.