Porcelain paving is strong, dense, and practically non-porous, making it ideal for outdoor spaces.
However, these same properties mean that choosing the correct jointing method is crucial for a durable and attractive finish. The choice between flexible and rigid systems depends on the intended use, the type of base construction, and environmental exposure.
Flexible Jointing Systems
Flexible jointing mortars are polymer- or resin-bound materials formulated for outdoor paving. They are often referred to as ‘brush-in’ or ‘self-compacting’ systems. Once cured, they form a semi-rigid joint that allows only limited movement. These systems are not soft or elastic, but they can tolerate small thermal or structural shifts. High-strength formulations are also suitable for driveways and commercial or forecourt applications when laid on a properly bound base.
Flexible jointing compounds are usually water-permeable, helping drainage and reducing surface runoff. They are easy to apply, frost-resistant, and ideal for patios, paths, and driveways. However, they require clean, deep joints—generally 25–30 mm—and should not be used where the sub-base is unstable.
Rigid Jointing Systems
Rigid systems are typically cement-based or polymer-modified mortars that create hard,
impermeable joints. They form a structural bond between slabs and are highly durable on stable, bound bases. Rigid joints are recommended for driveways, steps, courtyards, and commercial areas exposed to heavy foot or vehicle traffic.
Rigid grouts have little or no movement tolerance, meaning any base movement may lead to cracking. They also require careful cleaning during installation to prevent staining, especially on porcelain surfaces.
Comparison and Selection
Flexible systems provide limited flexibility, are permeable, and simple to maintain. Rigid systems create strong, impermeable joints with greater strength but less tolerance for base movement. For patios, flexible systems are generally ideal. For driveways and commercial installations, use either a driveway-grade flexible or a rigid system depending on the anticipated load and base design.
Correct joint geometry is critical: joints should be 3–10 mm wide and 20–30 mm deep. Always ensure paving is well-bedded, joints are clean, and weather conditions are suitable before grouting.
Proper preparation and curing are essential for ensuring long-term stability and consistent
appearance.
