Detailing flexible stone on curved walls and columns.

Curved work is where flexible stone stops being a substitute for something else and becomes the only sensible answer. It is also where most of the technical queries we receive originate — because a radius on a drawing and a radius on a substrate are rarely the same number.

What the sheet can and cannot do

The material bends, but it is not a fabric. Two limits matter:

• Minimum bend radius — a KASARO sheet handles a 50 mm radius. Below that, the surface begins to fight the substrate.
• Convex versus concave — a convex column is easier than a concave reveal. On the inside of a tight curve the sheet is in compression, and edges can lift.

The practical working minimum for production detailing is more conservative than the laboratory figure, because the radius has to survive site tolerances. We set the working limit per finish and per thickness, and confirm it against your actual substrate — not against the drawing's nominal dimension.

Setting out a curved elevation

For straight work, a panel layout is arithmetic. For curved work, it is a sequence:

1. Establish the true radius of the finished substrate, not the structural element behind it.
2. Divide the arc into panels that never exceed the maximum sheet length in either direction.
3. Place joints where the curvature changes, never across a tangent point.
4. Allow for movement at every edge that meets a rigid element — frames, sills, reveals.
5. Check the corner return: a 90° column corner in one sheet is possible only if the radius and thickness allow it.

This is what we produce as a setting-out drawing. Send the elevation in DWG or PDF and we return the panel layout with corner and return details, expansion joints and a cutting schedule — before the first sheet is produced.

Joints: the part that decides whether a curve reads

A curved wall in rigid stone needs mitred or curved-cut pieces, and every cut is a place where the figure breaks. A flexible sheet can be carried around a radius in one piece, which is why a forty-metre KASARO elevation holds together visually.

Match joints to the geometry, not to the sheet size. A joint that falls on a tangent is a joint that will read as a mistake for the next thirty years.

What to send us

With those six inputs we can tell you within a day whether the geometry is achievable, which thickness to use, and where the joints should fall.

On site: test before you commit

For any curved work we recommend a small-area test installation on the real substrate. Bonding three or four sheets around the worst radius takes an hour and removes the risk of a failed first elevation. Method statements and tool lists are issued with every order, and on-site commissioning support is included above 1,000 m².

Send us the curve

The technical department reviews curved elevations against the actual substrate and returns a setting-out drawing, a cutting schedule and a feasibility answer.