The case for leaving the formwork marks in
Sanding concrete smooth erases the only honest record a wall keeps of how it was made. In Mexico City we learned to stop apologizing for the seams.
The first wall we poured for the Tláhuac studio came out of its plywood molds streaked with board lines, a grid of round tie holes, and a single bruise where a panel had bowed under the wet load. My client wanted it ground flat. I spent two weeks last winter arguing that the bruise was the building telling the truth about its own weight.
Texture is a kind of timestamp
Raw concrete records the hour it was cast — the grain of the timber, the humidity of the morning, the volcanic stone that drifted to the surface as the mix settled. Polish it and you trade that record for a showroom finish that could have come from anywhere. We chose to keep the rake of the afternoon sun catching every seam instead.
A surface that hides its making asks you to trust it. A surface that shows the formwork simply tells you.
None of this is nostalgia. The board marks shed rain, the tie holes vent the slab, the flecked aggregate hardens the face against the dry valley wind. The wall earns its texture the way a hand earns its calluses — by doing the work and refusing to pretend otherwise.