The specification for the layered, textured concrete walls evolved through trial panels to achieve the appearance of layered rock strata and a slice through millions of years of geological deposits and formations.
Project Name: The Weston
Studio Name: FEILDEN FOWLES
Four key variables impacted the visual appearance:
- The first was the quantity of pigment added to achieve the desired colour;
- The second variable was the type of aggregate used, of which we selected three local stones – millstone grit, Leicestershire granite and magnesium limestone – graded on the wall with the hardest, granite, in the lower layers;
- Aggregate size was the third variable; our trials ranged from 10mm to 30mm in diameter;
- The final variable is the extent of jet washing after the formwork is removed, a light, medium or heavy pressure was tested to scour away different surface depths to expose the larger aggregates.
The final specification combined these variables to create a nuanced and natural variation across the wall, evoking weathered bands of sedimentary rock. Large detail drawings of each wall section were drawn to clearly communicate the colour, mix and aggregate exposure to the contractor. Of the trial walls, four have remained at the contractor’s premises in order for this material research to be available to others in the future, and one panel was struck in-situ, forming part of the building’s north elevation.
This was used as a contextual reference and agreed prototype. The resulting walls have depth, tone and patterns of erosion which tie it back to the millstone grit boulders extracted from the former quarry and surrounding the budding.