Most bluestone terraces are laid in large rectangles. This one goes the other way: 12″ × 12″ squares, turned 45 degrees to the walls, with a straight border course running around the perimeter. In a walled courtyard like this, the effect is tailored and a little old-world, like a stone floor that moved outdoors.
Why a diagonal works in a small space.
Square-set paving lines up with the walls and tells you exactly how big a room is. A diagonal breaks that. The joints run corner to corner, the eye follows them out to the edges, and the space reads larger than it is. Small squares add to the effect: more joints means a finer, denser texture, which suits a courtyard seen up close.
The border is what makes it look finished. Every piece that meets an edge on a diagonal is a cut triangle. A band of rectangular stone around the outside hides those cuts, gives the field a clean frame, and makes the transition to planting beds and walls crisp.
Small pieces want a slab.
A 12″ × 12″ square doesn't weigh much, and on a sand or gravel base small pieces can rock or creep over time. That's why we recommend building a terrace like this on a poured concrete slab, with the stone set in mortar. On a slab, 1″ bluestone is the standard thickness: the concrete does the structural work, and thinner stone keeps freight and cost down. (Our thickness guide covers the full rule.)
- Joints: mortared joints of about ¼″ to ⅜″ keep a tight, even grid.
- Border: rectangles such as 12″ × 24″ in the same stone, or a contrasting finish for a subtle frame.
- Drainage: build a gentle fall into the slab so water sheds away from the house.
Ordering a diagonal field.
At 12″ × 12″, one piece covers one square foot, which keeps the count simple. The waste is the part people underestimate. Every edge piece is cut, so plan on about 20% extra for the diagonal field, then order the border separately by its running length. Our estimating guide has the method.
| Element | Typical spec |
|---|---|
| Field | 12″ × 12″ × 1″, set on the diagonal |
| Border | 12″ × 24″ × 1″, square to the walls |
| Base | Concrete slab, stone set in mortar |
| Waste to plan | ~20% on the field |
A diagonal field and a straight border: the simplest way to make a small terrace look designed.
The same idea scales up: 18″ or 24″ squares on the diagonal read bolder and more modern, and at 24″ you can even open the joints to grass, as in our grass-joint grid. If you're weighing sizes for a courtyard, send us the dimensions and we'll lay out the options.