
Bendable Tile Backer Boards for Curves and Shapes
Precision-cut XPS foam board with cementitious coating — bends to a tight radius for curved walls, columns, arches and custom shapes while maintaining waterproofing and tile adhesion.
Insutile Flexboard is a waterproof, thermally insulating tile backer board engineered for curves. Precision-cut slots run along one face of its high-density XPS core, letting the rigid 20mm board bend smoothly around archways, cylindrical columns, curved partition walls, bath panels, shower seats, and tailored architectural features — achieving radii as tight as 200mm, well beyond what standard flat boards allow.
Once shaped and fixed against a frame or wall, the slots are filled with tile adhesive to lock the curve in place and restore full structural rigidity. The result is a solid, waterproof, pre-primed cementitious surface ready for direct tiling, mosaic work, or plaster — with the thermal and acoustic benefits of the XPS core built in.
Standard boards are 20mm thick with a 200mm minimum bend radius. Custom thicknesses and tighter radii are available to order for specialist projects.
Ready for tiling straight out of the box, Insutile Flexboard is cost-efficient, easy to install, and the fastest way to turn complex curved designs into finished surfaces.
Precision-cut slots on one surface enable smooth bending to tight radii without cracking or damage.
Fill slots with adhesive to restore full structural rigidity and create a permanent curved substrate.

Insutile® Flex Board delivers superior performance for curved applications:
Pre-slotted design allows smooth bending to tight radii without cracking or structural compromise.
Pre-cut slots bend smoothly to tight radii — columns, arches, and curved bath panels with no fracture.
XPS core is inherently waterproof and maintains moisture resistance even when bent and filled.
Closed-cell XPS core resists moisture even when bent and adhesive-filled — true wet-area durability.
Cementitious surface bonds reliably with all standard tile adhesives on curved surfaces.
Cementitious face bonds to all tile adhesives on curves — no movement, no bond failure.
No need for on-site slotting — simply bend along the precision-cut slots and fill with adhesive.
Factory slots eliminate on-site cutting — bend, fill with adhesive, done.
Fill slots with adhesive to restore full structural rigidity for a permanent, solid curved substrate.
Once adhesive fills the slots the board cures rigid — solid load-bearing curves.
Bends either way — slits inside the curve, or smooth face inside — for total layout flexibility.
Bends either way — slits inside for tightest radius, or smooth face inside when layout demands.
Flexible yet durable — can be bent by hand without special equipment or tools.
Bends by hand — no specialist bending machinery, no equipment rental.
Compatible with ceramic, porcelain, and natural stone tiles of all sizes and styles.
Supports ceramic, porcelain, and natural stone on curves — no material restrictions.
Perfect for creating curved walls, columns, arches, niches, and custom architectural shapes.
Perfect for curved walls, columns, arches, and niches — bring design vision to life.
Insutile® Flex Board — available dimensions and key performance specs:
| Thickness | Width | Length |
|---|---|---|
| 20 | 600 | 1200 |
| 20 | 600 | 2400 |
Flex Board bends to a minimum radius of 200 mm using its factory-cut slots — ideal for columns, arches, curved partitions, and organic architectural shapes. No heat forming, no site-mixed forms, no timber bracing required to hold the curve.
Bends either way. Preferred: slits inside the curve for the tightest radius — fill slits with adhesive and embed fiberglass mesh across the curve. Alternative: smooth face inside when the layout demands it.
Ideal for a wide range of applications in residential, commercial, and specialty settings.
Seven essential steps for a successful Insutile® Flex Board install. Click a step to view its plate.
Measure the curved surface and cut Flex Board to length using a fine-tooth saw or utility knife — no power tools needed.
Cut to length with a fine-tooth saw.
Confirm curve falls within min-bend spec.
Test the curve before any adhesive.
Tile adhesive into slots + substrate.
Bend into place; press firmly.
Pack slots with adhesive; add mesh if slits are inside.
Let cure, then tile directly.
Flex Board can be bent either way. Preferred: bend with the slits on the inside of the curve for the tightest radius, fill the slits with cement-based adhesive, and embed fiberglass mesh across the curve for extra support.
The steps shown are a recommended installation guide. Site conditions, substrates, and finishes vary — always consult a qualified contractor or specifier to confirm the correct method for your project.
Insutile® Flex Board outperforms alternatives for curved applications:
| Property | Insutile® Flex Board | Scored Standard Board | Flexible Plasterboard | Render on Mesh |
|---|---|---|---|---|
| Minimum Bend Radius | Very Tight (150mm+) | Very Limited | Moderate | Limited |
| Tile-Ready Surface | ✓ | ✗ | ✗ | ✗ |
| Waterproof Core | ✓ | ✗ | ✗ | ✗ |
| Structural After Bending | ✓ | ✗ | ✗ | Partial |
| Installation Speed | Fast | ✗ | Moderate | Slow |
| Curve Quality Consistency | Excellent | Poor | Good | Variable |
| Weight | Lightweight | Heavy | Light | Heavy |
Insutile offers a complete line of specialty construction insulation products:
Our technical team is ready to help you choose the right thickness, discuss bend radii, and ensure perfect installation on your curved surfaces and architectural features.