Significant dirt build-up can also detract from the artists’ original intention and even promote certain types of degradation. Paintings are prone to picking up surface dirt during display and over time, which can alter the appearance of the colours by reducing brightness and saturation, and changing surface gloss. For access to the spaces, the architects cut new openings into the raw walls and left the edges exposed as an evidence of their intentional manipulation.In water sensitive paintings when a dampened cotton swab (for example) is gently rolled over the paint surface, some pigment and binder are removed, which can cause concern and impacts established conservation practices for modern and contemporary oil paintings.

Herzog and de Meuron tried to minimalize interference with the Tanks, as original patina with all its stains, marks and discoloration was preserved and, new concrete necessary for structural reinforcement, blends subtly into the overall patchwork. Yet, their charm lies in their roughness and their history is revealed through their exposed nature. Sculpted from raw concrete, these tanks seem to be in direct opposition to the pristine and formal geometry of existing white gallery spaces found above ground. “From the beginning, Tate’s and our objective for this new project has been to fuse the extension with the power station’s past and history, so that like the original conversion, it would always refer back to the building as it once was, which was rough and industrial,” explained Herzog and de Meuron.

Upon a site visit over ten years ago, Herzog and de Meuron were captivated by the potential of the power station for their ability to merge the history of the site with its contemporary purpose.

Tate modern tate modern oil tank walls