With projects, the challenge can always be in different things. Sometimes it's the scope, sometimes it's a tight deadline and sometimes it's the cultural importance. Our work on Fort Asperen in Gelderland definitely falls into the latter category. Within the restoration of 19th century Fort Asperen, we provided the 'roofing'. The higher goal for the fort? To be included on the UNESCO World Heritage List.

National heritage

Fort Asperen is one of the forts in the Nieuwe Hollandse Waterlinie (a major defence line in Dutch history). The large-scale restoration of Fort Asperen is part of the decision taken in 1999 to secure the future of the Waterlinie and have this piece of national heritage included on the UNESCO World Heritage List. The tower fort was built in 1846 and has served several purposes over the past century and a half: from transit point for people in hiding to art studio. Since its restoration, the fort has served as a tavern.

Old and new come together

Trisoplast was used for a fluid-tight covering layer on the fort's underground roof construction. The old stone construction, covering 1,600 m2, was leaking. Because of Trisoplast's flexible and good adhesion properties, we could easily connect the mixture to various old stone and concrete structures. Our seven-centimetre-thick mineral sealing layer thus blends beautifully and seamlessly into the underlying beautiful old structure and the soil layers and green areas laid on top of it.