Milton Keynes, United Kingdom

Fashion retailer Fossil (UK) Ltd began the refurbishment of its UK headquarters in Milton Keynes following the discovery of corrosion to thepowder-coating on the clad parapets. Although the original Sika-Trocal roof remained in perfect functional condition, Fossil opted to have anew Sika-Trocal-S 1.5mm system installed directly on top of the existing membrane.

Flat Roof Project Requirements

For the new system’s application, Fossil once again appointed Trocal licensed roofing contractor Telclad Ltd to carry out the works – the same company that completed the original project in 1981. As part of Sika-Trocal’s application to extend its British Board of Agrément (BBA) durability statement, samples of the original roof were removed and tested for flexibility and weathertightness.

Sika-Trocal Solutions

Originally installed in 1981, the Trocal-S 1.5mm mechanically-fixed system remained in perfect functional condition more than 30 years later. Demonstrating very similar flexibility and constitution performance to a brand new membrane, this helped Sika-Trocal to have the lifespan of its Type S and SG materials extended up to 35 years by the BBA.

The National Sales Manager for Sika-Trocal, commented: “As samples of the removed Trocal-S material showed very little difference in flexibility and constitution to the brand new membrane,these are now used on a regular basis to reinforce the product’s quality and longevity with clients and specifiers.”

“We know technology is constantly evolving and it’s important that architects are aware of the benefits of single ply membranes. Now with the BBA certification being increased to 35 years, the confidence specifiers have shown in using this excellent product has been officially recognised.”

Products Used


Sika-Trocal Type S 

Sika-Trocal Type SG