Cambridge Uni roof featuring Sika Sarnafil solution

The roof refurbishment of the Central Building at Cambridge University’s Fitzwilliam College is a very special one, as it is one of the first major projects to use a pioneering approach from Sika Sarnafil.

This new method combines the company’s single ply membrane with large areas of its Sikalastic 621, a liquid applied product cokmonly used for areas with complex detailing.

These systems were not the only Sika products to feature in the refurbishment, as they were joined by SikaFloor 420, ensuring a complete building envelope solution.

Working alongside architect Cullinan Studio, Roofing Contractors Cambridge (RCC) and the College itself, Sika Sarnafil developed this innovative waterproofing solution to refurbish the roof, which possesses a very complex design.

Area Refurbishment Manager at Sika Sarnafil, Neil Smith, commented: “From ground level you can see protruding ‘scalloped’ detailing on the roof. If you looked down on the roof from above, it is like a picture-frame, with the scallops forming the border around the edge of the flat roof.

“The challenge was to effectively waterproof both the flat roof – which itself had plenty of challenging details – and scalloped areas, while maintaining the look and integrity of the roof and the building as a whole.”

Dave Stewart from RCC added: “For us, the crucial element of this project was getting the seal right. We worked closely with Sika Sarnafil and did multiple tests to make sure the junction between the Sikalastic 621 and single ply membrane was formed using the most effective detailing.

“The use of Sarnametal created a strong bond between the two products, enabling them to be successfully sealed together.

“This was by far the most challenging part of the project, but demonstrates how well these products can work together for roofs with incredibly complex detailing.”

Alex Abbey from Cullinan Studio was keen to minimise weight on the roof and wanted to steer clear of asphalt and similar products, so Sika Sarnafil’s lightweight products were an ideal choice.

“We needed a product that would not only effectively waterproof but that would sit over the copper scallops and maintain the shape’s detail. The Sikalastic 621 proved ideal and worked in harmony with the Sarnafil membrane.

“As did the SikaFloor 420, which was used on the façade and underside of the scallops; a complete solution from Sika.

“And importantly, the completed roof was awarded a Sarnafil Plus guarantee by Sika, a must for the client, preserving the building as an architectural landmark and study area.”
 

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Watchmead,
Welwyn Garden City,
Hertfordshire,
AL7 1BQ,
United Kingdom

Phone: 01707 394444
Fax: 01707 329129

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