Cast the unit upside down, flip it, stack it. The floor of the form becomes the top of the wall.
Precast wall units that combine balloon-cast concrete pebbles with red brick facings — a rock-and-lumber aesthetic, not the pink Instagram look.
The pebbles are the bulk fill, not an inclusion: concrete cast in balloons, packed between two faces of red brick, and squashed out of round by the weight of everything above them while the pour sets.
The unit is cast the wrong way up on purpose. Whatever the form floor gives you is the face the wall shows at the top, so the unit comes out, gets turned over, and goes on the stack that way.
Target unit is about 2′ wide and 1′ tall; the freestanding walls are about 2′ high. Two courses, and the wall is up.
The look is a constraint rather than a finish — rock and lumber, not the pink poured-and-polished thing — which is why the first test pour is a facings test and not a strength one.
Three moves, and the second one is the whole trick.
Balloons are the bulk fill
Concrete pebbles, cast in balloons, doing the volume of the unit between a brick facing on each side.
Cast upside down
The unit is poured inverted, so the floor of the form comes out as the top of the wall. The balloons squash under the weight while it sets.
Flip and stack
Out of the form, turned over, stacked. Two courses of a 1′ unit make the roughly 2′ freestanding wall.
Nothing poured. A test plan, in order, from September 2026.
The order is the point. The facings box answers what the wall looks like, the taller box answers what the balloons do under load, and neither answer is worth guessing at in the other's absence.