To achieve a strong and durable finish, most brush-in jointing compounds require your patio joints to be at least 3mm wide and 25mm deep. Shallow gaps will not hold the mixture correctly, which can lead to cracking. If your joints are too shallow, you may need to rake out the old bedding material to create enough depth before applying the new compound.
Choosing and Applying Patio Jointing Compound
Filling the gaps in patios and pathways helps create a seamless surface that resists weed growth and weather damage. The jointing compound category includes brush-in grouts, resin-based sands, and pointing mortars designed to lock paving stones together firmly. Whether completing a large driveway or a smaller garden path, these mixtures provide a solid, long-lasting finish. They are compatible with a wide range of surfaces, working exceptionally well alongside traditional concrete paving slabs and natural stone paving flags to complete any outdoor space.
Most modern compounds cure upon contact with the air, meaning they can be swept directly into the joints without complex mixing or waiting for dry weather. Many options are water-permeable to assist with surface drainage, preventing puddles from forming around rustic cobbles or smooth porcelain tiles. Technical specifications typically include frost resistance and compliance with standard paving requirements, ensuring the joints will not crack or wash away during heavy rain or freezing winter temperatures.
Supplied in ready-to-use 15kg or 20kg tubs, applying these products is highly straightforward and saves significant time during installation. The compound is simply brushed across the wetted surface and worked into the gaps, setting hard once dry while remaining flexible enough to handle slight ground movement. For a neat and flush finish, standard hand tools like trowels can be used to strike the joints lightly before they fully cure, leaving a smooth, professional appearance that withstands regular power washing and sweeping.
Jointing Compound FAQ's
Yes, many modern compounds are designed for all-weather application and can be used during wet conditions. In fact, thoroughly soaking your paving before and during the application process is highly recommended, as the water helps wash the sand mixture deeply into the joints and prevents any residue from sticking to the surface.
In dry and mild conditions, your patio should be safe to walk on within 24 to 48 hours after application. However, it typically takes between three and seven days for the mixture to fully cure and reach its maximum strength. Cold or damp weather will naturally extend these drying times, so it is best to avoid heavy foot traffic or pressure washing until the joints feel completely solid.
Applying brush-in compound is a highly straightforward task that does not require mixing or heavy machinery. You will simply need a hose to thoroughly wet the area, a stiff yard brush to sweep the mixture into the gaps, and a soft broom for the final clean-up. For a particularly neat finish, a pointing trowel or jointing iron is useful for striking the joints lightly as they begin to set.
Any unused compound can be saved easily, provided it is an air-curing product. Simply return the remaining mixture to its original tub and cover it with a layer of clean water, ensuring the sand is completely submerged. This water barrier stops the curing process, allowing you to seal the lid tightly and store the tub in a cool, frost-free place for later use.