Functional joints for Poppelsdorf Castle

Poppelsdorf Palace in Bonn is one of the region’s most significant historic structures and has shaped the cityscape of the former electoral capital since the 18th century. As part of a comprehensive renovation in accordance with historic preservation standards, the historic complex—including the inner courtyard—was restored to both ensure the long-term preservation of the building’s structural integrity and meet today’s functional and technical requirements.

As part of the redesign, the company Otto Bau from Dernau was awarded the contract in 2025 to renovate the approximately 950 m² inner courtyard.

Requirements and Challenges

The particular challenge of the project was to preserve the historic character of the palace while creating a durable and technically functional paved surface. Small stone pavers in three different shades were used for the courtyard design, creating a sophisticated paving pattern.

Since water could not seep into the subsoil in the courtyard area, the surface had to be constructed with a water-impermeable jointing system. Surface water was to be specifically drained away via the slope without placing a burden on the historic building fabric or the subsoil.

ROMEX® Solution

For grouting the paving surface, the choice fell on the cementitious paving joint mortar ROMPOX® - 301 CEM-PF. The material meets the requirements for a water-impermeable joint and is ideally suited for areas with controlled surface drainage.

The combination of high-quality small-stone paving and a durable joint resulted in a technically reliable and visually appealing surface that blends harmoniously into the castle’s overall historic appearance.