What is jointing compound and joint sealant?

Jointing compound and joint sealant are materials packed into the gaps between individual paving units such as block paving, slabs, or stone. These products come in several forms: polymeric sand (a blend of sand and resin particles), polyurethane resins, silicone sealants, and other polymeric compounds formulated to harden and bind after application.

The primary purposes are structural and protective. By filling the joints, these materials lock adjacent units together, distributing load more evenly across the surface and improving overall stability underfoot. They also seal the gaps against moisture, preventing water from pooling below the pavers and compromising the sub-base. On a practical level, they block dirt, seeds, and organic matter from settling into the joints where weeds can establish and grow, reducing long-term maintenance.

Different jointing compounds suit different settings. Polymeric sands work well for driveways and patios where foot traffic is moderate, while polyurethane and resin-based sealants offer stronger adhesion and flexibility for areas prone to movement or settling. Permeability is another consideration: some products are designed to allow drainage for gardens and flood-prone areas, while others are fully bonded and impermeable.

Proper application depends on the paver type and site conditions. A qualified patio paving contractor in Cheltenham will select the right product for your surface and ensure joints are correctly prepared and filled to maximize durability and appearance.