Castellum | De Hoge Woerd


Some time ago, Castellum Hoge Woerd opened in Leidsche Rijn in Utrecht. It is a life-size reconstruction of a Roman fortress as it must have stood there around the beginning of the era, complete with battlements, watchtowers and gates. Alderman Kees Geldof symbolically opened the fortress by handing over a Roman gate key, which was found at the location, to the residents of the newest part Utrecht.

In addition, the fortress also offers space for the impressive arrangement of the preserved Roman ship de Meern 1. This ship, found in 1997, is one of the most spectacular finds ever made in The Netherlands.


On the outside, the walkways had to be provided with a seamless seal that could be walked on. Keeping the wooden construction in mind, the movements from the subsoil as well as expansion and contraction had to be taken into account.


Prokol choose for an inverted roof made of a substructure, a vapor barrier layer, an insulation layer of EPS, finished with waterproof sheet material and our Hotspray Polyurea 136-T/05.

The waterproof sheet material was mechanically attached to the substrate. A gutter construction was realized on the side to drain the rainwater.

The seams were sanded and then provided with a special layer. These were then sanded again so that smooth transitions were created. The substrate was provided with a special sealing primer.

As a seamless skin, a layer of Rocathaan Hotspray PA 136-T was applied in a thickness of 3 mm. Rocathaan Hotspray PA 136-T has crack-bridging properties so that any effect from the substrate can be absorbed.

End result

The architect and, above all, the users of the space are extremely satisfied with the end result. Despite the red color, the space radiates warmth and tranquility. The seamless finish is also easy to maintain.

Project details

Client: Municipality of Utrecht

Architect : SKETS architecture studio

Applicator : Krimpex Coating Systems

Implementation : 4th quarter 2014 and 1st quarter 2015

Function : Waterproofing and Decorative Finish

System applied : Prokol DSN/136-T/AS