How to Apply Paving Jointing Compounds Correctly

When it comes to jointing paving slabs, there are a few different methods you can use and it’s quite often a debated topic among those who have spent time doing outdoor paving projects and renovations. 

Paving jointing compounds, which are a type of patio grout, are becoming increasingly popular for their ease and convenience – and when used correctly, are just as effective as cement mix. Not only do jointing compounds remove the laborious task of mixing sand and cement, but they are very easy to get the hang of, saving you lots of time and hassle. 

Perfect for outdoor tiles, slabs and paving stones, ready-mix jointing compounds are suitable for a whole host of patio or driveway projects and can even be applied to any existing exterior paving for new features or touch-ups. 

If you’re new to using off-the-shelf patio jointing compound products, here’s a guide on how to use them.   

Find the right paving jointing compound for your needs 

Before you get started, there are two different types of patio jointing compounds to choose from. These are:

• Single-tub ready-mix resin compounds 
• Two-part Slurry mixes (with part-mixed components)

For most patios, pathways and DIY projects at home, ready-mix jointing compounds are sufficient. The slurry mixes (which usually require you to add the hardener into the resin/sand and whisk for several minutes) offer professional strength and performance, making them suitable for high vehicle traffic areas. 

While the single-tub ready mix option is by far the most convenient, both options are still much easier than having to create your own cement mix. 

For porcelain patios, there are specialist porcelain grout products available. 

How to apply resin-based compounds correctly

If you’re looking for a paving slab jointing compound that is easy to use, giving you consistently high-strength performance every time, single-tub compounds are ideal. These usually come vacuum-packed for ease and offer a range of colours to suit your paving (such as the Nexus ProJoint™ Fusion™ which comes in neutral, mid grey, basalt and black). 

To apply resin-based paving compounds, follow these steps:

1. Soak the laid slabs with water with a hose – make sure the slabs are as damp as possible as this type of compound works best when the stone is wet. 
2. Pour the patio jointing compound onto the slabs and wet the compound with a hose. 
3. Use a wire brush to brush the compound into the gaps, using extra water when required. 
4. Encourage any last bits of the compound into the gaps with more water if necessary. 
5. All to cure for 24-48 hours. 

How to apply two-part slurry mixes correctly

This is a slightly more technical paving jointing compound to use, but it’s extremely high strength, meaning it can take the weight of heavy vehicles. When mixed with the hardeners, the compound develops its setting properties. 

Here are the steps to follow for applying it:

1. Ensure the slabs are clean before application and wet them thoroughly for best results.
2. Make sure the paving slab jointing compound is mixed well – do this with a plasterer’s whisk in its tub for three minutes or until it has the consistency of a slurry.
3. While the slabs are still wet, brush the slurry into the gaps. Patio jointing squeegee tools tend to work best for this part. 
4. Leave the compound to rest for 10-15 minutes then use a wire brush to sweep away any of the excess sand/slurry to prevent staining of your stone. 
5. Let garden patios/pavements cure for 12 hours, and allow driveways to cure for 24 hours in order to handle the weight of traffic. 

How to apply porcelain jointing compound 

If you are laying porcelain paving or flooring, you’ll find a range of ready-mixed porcelain grout products that are very easy to use.  

These are the steps for applying porcelain jointing compound: 

1. If your grout needs mixing, follow the instructions on the container and ensure the mixture is smooth and lump-free. This is best done using a drill and a paddle or plasterer’s whisk. 
2. Allow the mixture to stand for a couple of minutes before mixing again. This will allow the polymer additives to dissolve and activate.
3. Work the grout into the joints using a rubber float tool and work on one small area at a time. 
4. Keep working the grout into joints until it is flush with the paving, and remove excess grout as you go. 
5. Use a damp cloth to remove any leftover grout on the tiles – this can be done up to 30 minutes after applying. Textured porcelain paving slabs may need further cleaning once the grout is dry. 
6. Allow to cure before walking over the paving for at least three hours. For a full cure, wait 72 hours – but always add extra time in colder temperatures. 

Top tip: If you are working in hot temperatures, you can use a fine mist spray to keep freshly grouted joints damp.